Enhancing Mechanical and Thermal Properties of ...downloads.hindawi.com/journals/apt/2019/2318347.pdf · ReseachArticle Enhancing Mechanical and Thermal Properties of Polyurethane

Research ArticleEnhancing Mechanical and Thermal Properties of PolyurethaneRubber Reinforced with Polyethylene Glycol-g-Graphene Oxide

Li Wang 1 Wen Fu 2 Wenlong Peng2 Haotuo Xiao2 Shenglin Li2

Jianning Huang2 and Cuiwen Liu2

1College of Chemical Engineering Guangdong University of Petrochemical Technology Maoming 525000 Guangdong China2College of Material Science Guangdong University of Petrochemical Technology Maoming 525000 Guangdong China

Correspondence should be addressed to Wen Fu a449192213163com

Received 5 June 2019 Accepted 21 July 2019 Published 5 August 2019

Guest Editor Hong Liang

Copyright copy 2019 Li Wang et alThis is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

This paper attempted to achieve the purpose of increasing the tensile strength and toughness of polyurethane rubber (PUR)simultaneously by introducing polyethylene glycol (PEG) onto the surface of graphene oxide (GO) to introduce hydrogenbond interactions into the PUR-GO system GO was grafted with PEG and added to PUR by mechanical blending Thepolyethylene glycol-g-graphene oxide (MGO) was characterized by infrared spectroscopy Raman spectroscopy X-ray diffractionand thermogravimetric analysis The PURMGO composites were tested by tensile testing machine thermogravimetric analysisdynamic thermal analysis and scanning electron microscopyThe results demonstrated that PEG was successfully grafted onto thesurface of GO and the grafting rate was about 37 The grated PEG did not affect the crystalline structure of GO The addition ofMGO could improve the thermal stability of PUR vulcanizate After the addition of GO the glass transition temperature (Tg) ofvulcanizate was shifted to higher temperatureHowever theTg of vulcanizate reinforced byMGOwas shifted to lower temperatureThe strength and toughness of vulcanizate were significantly improved by adding MGO The reason was that the hydrogen bondinteractions between MGO and PUR were destroyed and the hidden length was released during the strain process A lot of energywas consumed and thus the strength and toughness of PUR vulcanizate were improved

1 Introduction

Generally raw rubber without reinforcer has poor mechan-ical properties For most practical applications the rubbershould be reinforced with some additives Carbon black andsilica are the commonly used reinforcing agents In recentyears graphene has been studied as a new type of reinforc-ing agent for rubber The Youngs modulus of monolayergraphene is about 11 TPa and the fracture strength is 125GPa [1] Hence graphene should have promising prospectin the field of rubber reinforcement [2ndash4] However it wasreported that graphene could increase the strength of rubbermatrix but will damnify the toughness and ductility [5ndash7]How to optimize the strength and toughness of graphenereinforced rubber is still an important issue in the field ofmaterial science

Natural biomaterials such as spider silk and animal bonealways exhibit an amazing balance among the strength

toughness and ductility Studies have revealed that it is dueto the sacrificial bonds and hidden length at the soft-hardinterface so these natural biomaterials can achieve both highstrength and ductility [8ndash10] Inspired by the structure ofthese natural biomaterials some reports about constructingsacrificial bonds at the interface between inorganic filler andelastomer to increase the strength and toughness of materialshave emerged recentlyThe strength of noncovalent sacrificialbonds such as hydrogen bond [11 12] 120587-120587 conjugate interac-tions [13]120587-cation interactions [14] and ionic bonds [15] areweak however through the breaking of reasonable sacrificialbonds and sliding of some chain segments the interfacial loadcould be transferred and the strength could be enhanced

Tang [16] constructed a network of sacrificial metal-ligand bonds in pyridyl styrene-butadiene rubber (VPR)and achieved 278 MPa tensile strength of the vulcanizatewhich was higher than that of VPR reinforced by carbonblack and silica Huang [17] modified solution polymerized

HindawiAdvances in Polymer TechnologyVolume 2019 Article ID 2318347 11 pageshttpsdoiorg10115520192318347

2 Advances in Polymer Technology

MGO

OH

OH

OH

OH OH

OH

OH

OH

OH

OH OH

OH

COOH

COOH

OH

OH

OH

OH

OH

O

O

O

OO

O

O

O

O

OO

O

HOHOHO

HOOC

O

OO

O

O

OO

OO

C

C

C

C

C

O

O

O

O

OO

OO

O

O

O

O O

OH

COOH

COOH

COOH

COOHCOOH

COOH

GO

75∘C

Figure 1 Preparation of polyethylene glycol graft modified graphene oxide

styrene butadiene rubber (SSBR) with triazolidinedione byclick chemistry and introduced the urezo groups to SSBRto provide hydrogen bonds thereby the sacrificial bondswere constructed in the system The tensile strength of themodified SSBR had been significantly enhanced to 764 MPawhich was higher than that of the pure SSBR Wu [18]used themaleic anhydride-modified polyisoprene rubber andaminomodified carbon nanodots to construct the networkof sacrificial bonds and used unsaturated bonds to constructthe chemically cross-linked network The tensile strengthapproached 305 MPa when the dosage of carbon nanodotswas only 3 phr which was stronger than that of the poly-isoprene rubber reinforced by 40 phr N330 carbon blackMao [19] added a kind of VPR into GOstyrene butadienerubber (SBR) system and constructed ionic bond interactionbetween pyridine group (positive) in the vinyl pyridine unitof VPR and oxygen-containing functional group (negative)on the surface of GO Wu [20] characterized the interfacialinteraction of VPRGO composites by the dielectric relax-ation spectra of the vulcanizates with different interactions(ionic bond hydrogen bond) The results revealed that thevelocity of segmental relaxation and interfacial relaxation ofVPRGO composite bonded by ionic bond was higher thanthat of composites bonded by hydrogen bond indicating thatthe internal interaction of GOVPR composites bonded byionic bond was stronger Li [21] found that the dissociationenergy of hydrogen bond in polyurethane was about 167kJmol In general the bonding energy of C-C covalent isover 300 kJmol It means that the hydrogen bond is likely tobe destroyed during the strain process and additional strainenergy will be consumed so the strength and toughness ofmaterial are guaranteed

In the present paper graphene oxide was grafted withpolyethylene glycol 600 by means of the reaction betweenthe carboxyl groups on the surface of graphene oxide andthe hydroxyl groups at the end of polyethylene glycol andthen added to PUR The grafted graphene oxide reinforcedthe PUR significantly through hydrogen bonds on the filler-rubber interfaces Additional strain energy was dissipatedby destructing the hydrogen bond sacrificial unit duringthe strain process thereby the strength and toughness wereimproved simultaneously

2 Experiment

21 Materials Polyurethane rubber (PUR type of HA-5)was purchased from Shanxi Institute of Chemistry Indus-try China Graphene oxide (GO lamellar size of 10-50120583m layers of 6sim10) was purchased from SuZhou TanfengCo Ltd China Polyethylene glycol (PEG AR number-average molecular weight of 600) 4-dimethylaminopyridine(DMAP AR) N N-dicyclohexylcarbodiimide (DCC AR)and dicumyl peroxide (DCP AR)were purchased from SigmaAldrich Company USA All materials were used directlywithout further treatment

22 Sample Preparation

221 Preparation ofGraedGrapheneOxidewith PolyethyleneGlycol 600 mg GO and 350 ml toluene were added to a 500ml single-neck flask at room temperature and dispersed byultrasound for 30minutesThen 20 g PEG 058 gDMAP and119 g DCCwere added to the flask successively and dispersedby ultrasound for 30 minutes thereafter the content wasstirred by magnetic force for 24 h at temperature 75∘C Thereaction product was filtered by polytetrafluoroethylene filterpaper with 02 120583m aperture Filter cake was washed with 50ml of toluene and 700ml of deionized water in turn and thenwas dried in vacuum oven at 60∘CThe product was denotedas MGOThe preparation process was depictured in Figure 1

222 Preparation of PURMGO A mill (type of XK-150Zhanjiang Machinery Factory China) was used to mix theraw materials The roller gap of mill was adjusted to about01 mm then PUR GO (or MGO) and DCP were added inturn After each addition the PUR compounds were side-cutboth sides in turn 5 times and then triangle-packed 5 timesand thin-passing 5 times finally the rubber compounds wererolled into 2 mm sheet After being parked for 24 h the sheetwas vulcanized on a press (type of KSH-R100 DongguanKesheng Industrial Co Ltd China) with 16 MPa for t

90+2

min at 175∘C The mass ratio of PUR DCP was 100 2 Theamount of GO or MGO was variable For example if theamount of MGO was 05 phr the sample was marked asPURMGO-05

Advances in Polymer Technology 3

23 Characterizations The chemical structure of sampleswas characterized by an 8400S FTIR spectrometer (Shi-madzu Japan) The scanning range was 4000sim400 cmminus1the scanning time was 32 and the sample was produced bypressing potassium bromide troche

Raman spectrum was determined by a LabRAM AramisRaman microscope (HORIBA Jobin Yvon France) The exci-tation source was He-Ne laser and the excitation wavelengthwas 5320 nm

The crystalline structure was analyzed using a D8 X-raydiffractometer (Bruker Germany) The radiographic sourcewas Cu-K120572 the accelerated voltage was 40 kV the emissioncurrent was 40mA the scanning speed was 01 sstep and thescanning range was 2120579=5sim60∘

The thermal stability was characterized by a 209 F3thermogravimetric analyzer (Netzsch Germany) The exam-ination range was 50sim900∘C for GO and MGO fillers andthe examination range was 50sim800∘C for PUR rubber Theheating rate was 30 Kmin and the nitrogen stream was 20mlmin

The GOPEG samples for FTIR Raman spectra X-raydiffraction test (XRD) and thermogravimetric test (TGA)were purified by reflux condensation with toluene for 2 hthen washed with 50 ml toluene and dried

The dynamic mechanical properties were performed ona 214E dynamic mechanical analyzer (Netzsch Germany) atstretching mode with a heating rate of 3 Kmin from -80sim60∘CThe exciting frequency was 5 Hz and the amplitude was60 120583m

The tensile properties were measured with a 2080 tensiletesting machine (UC Taiwan) according to the GBT 528-2009 the thickness of specimens was 10 mm the tensilespeed of cyclic tension-recovery test was 50mmmin and thetensile speed of tensile strength test was 200 mmmin Thesample shape was a dumbbell-shaped strip

The structure and morphology were recorded by aTM3030 scanning electron microscopy (Hitachi Japan)The acceleration voltage was 15 kV and the samples werefirst sputtered with platinum film before measurement Theinvestigated surface was the tensile fracture surface

3 Results and Discussion

31 Interface Structures of GOPEG The FTIR analyses wereused to detect the molecular bonds details of the GO MGOand PEG MGO GO and PEG were analyzed with FTIRand the obtained spectra were shown in Figures 2(a) and2(b) Compared with GO the peak intensity of MGO at 3440cmminus1 2921 cmminus1 and 1105 cmminus1 was bigger These three peakscorrespond to the stretching vibration of the O-H bond C-Hbond and C-O-C bond respectively [22] At 1257 cmminus1 and831 cmminus1 two new peaks appeared in MGO which resultedfrom the stretching vibration of the C-O bond and the out-of-plane bending of O-H bond All of these changes came fromthe grafting of PEG which indicated that the PEG interactedwith GO and successfully grafted on the surface of GO

Raman spectroscopy can effectively characterize the crys-tal structure and charge transfer of GO The Raman spectra

of GO and MGO were shown in Figure 2(c) It can be seenfrom the figure that GO had two distinct characteristic peaksat 1580 cmminus1 and 1342 cmminus1 which correspond to G-bandand D-band of GO respectively [23] MGO also exhibitedthe G-band and D-band peaks but the peak position of thesetwo peaks shifted to 1589 cmminus1 and 1334 cmminus1 respectivelyThis is because the interaction between PEG and GO leads toelectron transfer [24] In addition theD-band is related to thevibration of sp3 hybridized carbon and defects on the edges ofGO formed during the oxidationTheG-band is caused by thevibration of sp2 hybridized carbon in the graphite lattice Theintensity ratio of D-band and G-band (IDIG) is commonlyused to characterize the defects of graphene and monitor thefunctionalization of graphene [23]The larger the IDIG is themore the C atomic lattice surfaces defects exist The smallerthe IDIG is the less the C atomic lattice surfaces defects existThe IDIG of GOwas 023 while that ofMGOwas 083 whichwas significantly higher than that of GOThis is because PEGwas randomly grafted on the GO surface by covalent bondsresulting in the increase of the surface defects

Figure 2(d) showed the TGA analysis curves of GO andMGO The weight loss rate of GO at 200sim900∘C was only201 which was caused by the decomposition of oxygen-containing functional groups in the sample while the weightloss rate of MGO at 50sim200∘C was 125 which was causedby the loss of adsorbed water in the sample The weightloss rate at 200sim900∘C was 389 which was mainly dueto the ablation of polyethylene glycol molecules graftedon the surface of the sample Secondly it also includesthe decomposition of oxygen-containing functional groupson the surface of the sample Therefore the graft ratio ofpolyethylene glycol on the surface of GO was about 37

XRD can characterize the crystalline structure before andafter GO modification The XRD diagrams of GO and MGOwere shown in Figure 2(e) A narrow and strong diffractionpeak appeared at 264∘ in the diagram of GO correspondingto the interlayer spacing of 0337 nm In addition two weakerdiffraction peaks appeared at 446∘ and 546∘ which werethe typical peaks of the multilayer grapheme [25] Comparedwith GO MGO also showed diffraction peaks at these threeplaces which indicated that the addition of PEG on thesurface of GO did not affect the crystalline structure of GOnor did it affect the interlayer spacing of GO sheets What ismore MGO had a diffuse peak near 22∘ which could ascribeto the addition of PEG PEG was an amorphous substancewhich was grafted to the surface of GO by the covalent bondand led to the appearance of diffuse peak [26]

32 ermal Stability of PURMGO Composites The ther-mogravimetric analyses of PUR PURGO and PURMGOvulcanizates were shown in Figure 3 and Table 1 Comparedwith the pure PUR vulcanizate the initial decompositiontemperature (Ti) maximum decomposition temperature(Tmax) and termination decomposition temperature (Tt) ofthe vulcanizate added with 05 GOwere increased by 19∘C168∘C and 178∘C respectively Meanwhile the Ti Tmax andTt of the vulcanizate added with 05 MGO were increasedby 27∘C 189∘C and 229∘C respectively When the addition


GOMGO

80

85

90

95

100

Tran

smitt

ance

()

3500 3000 2500 2000 1500 1000 5004000Wavenumber (＝Ｇminus1)

(a)

PEG

20

40

60

80

100

Tran

smitt

ance

()


(b)

G-bandD-band

Inte

nsity

(au

) MGO

GO

1200 1300 1400 1500 1600 1700 18001100Raman Shift (＝Ｇminus1)

(c)

GOMGO

40

50

60

70

80

90

100

Mas

s (

)

200 400 600 800 10000Temperature (∘C)

(d)

GOMGO

Inte

nsity

(au

)

10 20 30 40 50 6002 (∘)

(e)

Figure 2 Structural characterizations of GOMGO and PEG (a) FTIR characterization of GO andMGO (b) FTIR characterization of PEG(c) Raman spectra characterization of GO andMGO (d) TGA characterization of GO andMGO (e) XRD characterization of GO andMGO

of GO or MGO were increased to 1 the Ti Tmax andTt of the vulcanizates were increased again This indicatedthat the addition of GO or MGO was helpful for improvingthe thermal stability of the vulcanizates This improvementphenomenon was the same as the addition of a filler such as

carbon black to the rubber matrix to improve the thermalstability of the vulcanizate [27] In addition the thermalstability of MGO-added compounds was better than that ofGO-added compounds at the same dosage because MGOwas dispersed better in the rubber matrix after the graft


PURGO-0PURGO-05PURGO-10PURMGO-05PURMGO-10



320 340 360 380 400 420300Temperature (∘C)

400 420 440 460 480380Temperature (∘C)

0

20

40

60

80M

ass (

)

20

40

60

80

100

Mas

s (

)

200 400 600 8000Temperature (∘C)

0

20

40

60

80

100

Mas

s (

)

Figure 3 Thermogravimetric analyses of PUR PURGO and PURMGO composites

Table 1 The key data of thermogravimetric analyses of PUR PURGO and PURMGO composites

Sample Ti(∘C) Tmax (∘C) Tt(∘C)PURGO-0 3888 3957 4044PURGO-05 3907 4125 4222PURGO-10 4024 4189 4395PURMGO-05 3915 4146 4273PURMGO-10 4110 4203 4428

modification and formed stronger interaction with rubbermolecular chains through molecular hydrogen bond [28]What is more after adding GO orMGO the increasing rangeof theTmax andTt of the vulcanizatewas larger than that of theTi This is because GO or MGO is a lamellar structure whichwould form a physical fire barrier layer in the rubber matrixafter high-temperature combustion The escape of decompo-sition products was slowed down and the further degradationwas delayed because of the existence of this fire barrier [29]

33 Dynamic Mechanical Property of PURMGO CompositesThe dynamic mechanical properties of PUR PURGO andPURMGO vulcanizates were shown in Figure 4 As canbe seen from Figure 4(a) compared with the pure PURvulcanizate the initial storage modulus of the vulcanizatewith GO or MGO was significantly increased This is becausethe rigidity of the filler phase is much larger than that of therubber phase and the addition of a rigid filler phase to theflexible rubber phase produces a significant reinforcing effect



minus60 minus40 minus20 0 20 40 60minus80Temperature (∘C)

0

1000

2000

3000

4000

5000

6000

7000

(MPa

)

(a)



minus02

00

02

04

06

08

10

12

Tan

(b)

Figure 4 Dynamic mechanical properties of PUR PURGO and PURMGO composites

[28]This effect caused the initial storage modulus of vulcan-izate to continue to increase when the filler phase content wasincreased from05 to 10 In addition the storagemodulusof PURMGOwas larger than that of PURGOwith the samefiller content This is due to the stronger interaction betweenMGO and PUR molecular chains [28]

The glass transition temperature (Tg) of elastomer cangenerally be obtained from the peak of the tan 120575-temperaturecurve It can be seen from Figure 4(b) that the Tg of thepure PUR vulcanizate was -308∘C and after adding 05 and10 of GO the Tg rose to -292∘C and -255∘C respectivelyIt was shown that the addition of GO caused the Tg ofvulcanizate to shift to higher temperature This indicatedthat the low temperature resistance of vulcanizate decreasedwhen GO was added This is because the glass transitiontemperature is the reflection of the transition of the chainsegments and the molecular chains motion form and it is thelowest temperature for the molecular chain segments to havethe motion ability in polymer GO had a strong interactionwith the rubber molecular chains limiting the ability of themolecular chain tomove resulting in the increase ofTg Afterthe addition of MGO the peak shape of the vulcanizate nearthe glass transition temperature had changed significantlyfrom the original high and sharp peak shape to a low andwide peak shape In general crystalline polymers exhibit awide temperature range during the melting process Thistemperature range is called the melting range which isrelated to the melting of crystals with different crystallinityat different temperatures Similarly PURMGO compositesalso exhibit a wide temperature range during the glasstransition process This temperature range can be calledthe glass transition range of the polymer which should berelated to the multiple motion mechanisms of the molecularchains in PURMGO composites During the dynamic strainprocess of PURMGO besides the movement of microrubber

molecular chain segments the destruction and recombina-tion of hydrogen bonds between rubber molecular chainsand MGO surfaces were also included This destruction andrecombination of hydrogen bonds will dissipate a portion ofthe energy resulting in the change of the tan 120575 peak shape Inaddition the glass transition range of PURMGO-05 was-304sim-403∘C and the glass transition range of PURMGO-10 was -316sim-427∘C Unlike the movement rule of theglass transition temperature of the vulcanizate with GO theglass transition temperature of the vulcanizate was shiftedto lower temperature and the low temperature resistance ofthe material was increased after the addition of MGO Thisis because the movement of hydrogen bonds is a kind ofsecondary transformation and can take place at lower temper-ature This also explains why the glass transition temperatureof PURMGO-10 was lower than that of PURMGO-05because more hydrogen bonds were formed

34 Tensile Properties of PURMGO Composites The intro-duction of sacrificial hydrogen bonds in PUR matrix couldimprove the toughness of thematerial which could be provedby the cyclic tension-recovery curve of vulcanizate When thePUR PURMGO-05 and PURMGO-10 samples wererespectively stretched to a preset strain of 100 the values ofthe hysteresis loops were 3303 3866 and 4299 respectively(Figure 5(a)) It can be seen that the obvious hysteresis lossoccurred after adding MGO and the value of hysteresis losswas increased with the increase of MGO content This isbecause the hydrogen bonds will be produced when MGOwas added to the PUR matrix and the hydrogen bonds inthe PURmatrix were destroyed during the stretching processand a large amount of energy was dissipated which led to theincrease of hysteresis loss

However hydrogen bond is reversible and it can beregenerated during the storage or heat treatment of material


PURGO-0PURMGO-05PURMGO-10

20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1

1 min10 min30 min120 min

00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()

Storage Time at 60∘C

(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)

Figure 5 Tensile properties of PUR PURGO and PURMGO composites

to achieve dynamic reversibility In general the recovery ofhydrogen bond is dependent on the time and temperatureTaking PURMGO-10 as an example the cyclic tension-recovery curves of PURMGO-10 vulcanizate with differ-ent recovery time at 60∘C were discussed (Figure 5(b)) Itcan be found that hydrogen bonds can spontaneously recoverduring high-temperature storage which leaded to a gradualincrease of hysteresis loss

The hysteresis loss recovery of PURGO-10 andPURMGO-10 under different conditions was quantita-tively compared in Figure 5(c) W

1st was the initial tension-recovery hysteresis loss of the sample and the W

2nd wasthe tension-recovery hysteresis loss of the samples after ithad recovered for a certain time at a certain temperatureFirstly with the prolongation of storage time the hysteresisloss of PURGO-10 gradually recovered which was relatedto the recrimping reentanglement of microrubbermolecular

chains and the interaction recovery of filler-rubbermolecularchains Under the same storage time the recovery rate ofhysteresis loss of PURMGO-10 was higher than that ofPURGO-10 This was because for PURMGO-10 sam-ple besides the recrimping reentanglement of microrubbermolecular chains and the interaction recovery of filler-rubbermolecular chains the regeneration of hydrogen bonds alsoled to an increase of recovery rate Secondly the recovery ratewas increased with the increase of the storage temperatureThe recovery rate of PURGO-10 was 8758 after storageat 25∘C for 120 min and the recovery rate was increased to9453 after storage at 60∘C for 120 min The recovery rateof PURMGO-10 was 9074 after storage at 25∘C for 120min and the recovery rate was increased to 9888 afterstorage at 60∘C for 120 min In addition under the samestorage temperature the recovery rate of the samples withMGO was higher than that of samples with GO This is not


only related to the recrimping reentanglement of microrub-ber molecular chains and the recovery of the interactionbetween fillers and rubber molecular chains but also to thefaster spontaneous recovery of dissociated hydrogen bondsat higher temperature

The stress-strain curves of PUR PURGO and PURMGO vulcanizates were shown in Figure 5(d) The tensilestrength and elongation at break of pure PUR vulcanizatewere 865 MPa and 431 After adding 05 GO the tensilestrength of the vulcanizate was increased to 1364 MPa andthe increase rate was 577 but the elongation at break wasdecreased to 417 and the decrease rate was 32When theamount of GO was increased by 1 the tensile strength ofthe vulcanizate continued to rise to 2475 MPa the rate ofincrease was 1861 the elongation at break was decreased to395 and the decrease rate was 84 It was shown that thetensile strength of vulcanizatewas improvedwith the increaseof GO content but the elongation at break was decreasedThat is the strength of vulcanizate was increased and thetoughnesswas decreasedwhenGOwas addedHowever afteradding 05MGO the tensile strength of the vulcanizate wasincreased to 2065 MPa the increase rate was 1387 theelongation at break was increased to 570 at the same timeand the increase rate was 322 When the amount of MGOwas increased by 1 the tensile strength of the vulcanizatecontinued to rise to 2644 MPa the increase rate was 2057the elongation at break continued to rise to 645 and theincrease rate was 496 It can be seen that the addition ofMGO is helpful for improving the strength and toughness ofvulcanizate simultaneously

35 SEM Analyses of PURMGO Composites SEM can beused to analyze the dispersion of fillers in rubber matrix andthe interactions between the filler and rubber matrix Thetensile fracture surface of PUR PURGO and PURMGOvulcanizates were shown in Figure 6 As can be seen fromthe figures the pure PUR vulcanizate had a relatively simplecross-section structure and the fracture surfaces were smoothin each fault (Figure 6(a)) After adding 05 GO or MGOthe fracture surfaces of the vulcanizates were rough andthe height difference between the cross-section layers wasreduced Moreover the cross-section layers were parallel-peeled (Figures 6(b) and 6(c)) This indicated that thereshould be a kind of force perpendicular to the direction oftensile stress during the fracture of vulcanizate This forceshould originate from the sheet exfoliation of graphene oxidelamellae from rubber matrix by the tensile force (as shownin the red circle in Figure 6(c)) When the amount of GOor MGO was added to 1 the sense of layering of thecross-section tented to be more obvious (Figures 6(d) and6(e)) because the filler and rubber matrix produced moresheet exfoliation Comparing PURGO and PURMGO with1 fillers (comparing Figure 6(d) with Figure 6(e)) it canbe found that the sense of layering of the cross-section ofthe PURMGO was stronger than that of PURGO and thesection of the PURMGO vulcanizate was rich and scatteredThe reason was that the compatibility between the rubbermatrix and GO was improved when GO was modified with

PEG and the dispersibility of MGO in the rubber matrix wasalso improved Therefore the interaction points between thefillers and the rubber molecular chains were increased andthe interaction force was improved

36 Mechanism on Strengthening and Toughening PURMGOComposites The strengthening and toughening mechanismof PURMGO composites was shown in Figure 7 InPURMGO system continuous hydrogen bonds were formedbetween the PUR molecular chains and the PEG molec-ular chains which was grafted on the surface of GO bycovalent bonds (120582=120582

0) During the stretching process the

PUR molecular chains were firstly oriented along the stressdirection (120582=120582

1) If the strain was increased continuously

(120582=1205822 1205823) the hydrogen bonds between PUR and PEG

would be gradually dissociated and the hydrogen bondinteractions would be destroyed gradually with the increaseof strain A large amount of strain energy was consumedand the hidden length hid between the PUR molecularchains and the PEG molecular chains was released duringthe strain process Thus the tensile strength and toughnessof the rubber material could be improved simultaneouslyIn PURMGO system the PUR molecular chains had beencross-linked because of the presence of DCP vulcanizingagent If the vulcanizate was not broken at the macroscopiclevel during the strain process it will show macrorecoveryunder the action of the DCP permanent cross-linking bondswhen the stress was removedMeanwhile the PEGmolecularchains and the PURmolecular chainswere close to each otherat the microscopic level whichmade it possible to regeneratehydrogen bonds between the PEG molecular chains and thePUR molecular chains during the storage or heat treatmentprocess and thereby the reversible recovery of hydrogenbonds was realized (120582=1205821015840

0)

4 Conclusions

The hydrogen bond sacrificial units were introduced into thePUR-MGO system by grafting PEG onto the surface of GOThe FTIR analysis showed the PEG was successfully graftedonto the surface of GO The TGA analysis indicated thegrafting rate was about 37 The XRD analysis determinedthe addition of PEG did not affect the crystalline structure ofGOThe hydrogen bond sacrificial units of PURMGO com-posites were destroyed and the hidden length was releasedduring the stretching process thereby the tensile strengthand elongation at break were improved simultaneously Com-pared with pure PUR vulcanizate the tensile strength andelongation at break of PURMGO-10 were increased by2057 and 496 respectively while the tensile strength ofPURGO-10 was increased by 1861 but the elongationat break was decreased by 84 In addition the addition ofGO or MGO can improve the thermal stability of PUR andthe improvement of MGO was better The Tg of PURGO-10 was increased by 53∘C However the Tg of PURMGO-10 was shifted to lower temperature What is interestingwas that a kind of glass transition range appeared due tothe introducing of hydrogen bonds What is more increasing


TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)

TM3030 N D44 times30k 30 m

(f)

Figure 6 SEM analyses of PUR PURGO and PURMGO composites (a) PURGO-0 (b) PURGO-05 (c) PURMGO-05 (d)PURGO-10 (e) PURMGO-10 (f) PURMGO-10

the heat treatment temperature and prolonging the heattreatment time were helpful for the reversible recovery ofhydrogen bonds

Data Availability

The figure and table data used to support the findings of thisstudy are included within the article

Conflicts of Interest

The authors declare that they have no conflicts of inter-est

Authorsrsquo Contributions

Li Wang and Wen Fu contributed equally to this paper


PUR PEGhydrogen bond

0 1 2 3 0lt lt lt

Figure 7 Strengthening and toughening mechanism of PURMGO composites

Acknowledgments

This research was supported by Natural Science Foundationof Guangdong Province (2017A030310663 2018A030307018and 2018A0303070003) Distinguished Young Talents inHigher Education of Guangdong (2016KQNCX107) Guang-dong Research Center for Unconventional Energy Engineer-ing Technology (GF2018A005) and Maoming Science andTechnology Project (Maokezi 2019 (33))

References

[1] C Lee X Wei J W Kysar and J Hone ldquoMeasurementof the elastic properties and intrinsic strength of monolayergraphenerdquo Science vol 321 no 5887 pp 385ndash388 2008

[2] V D Punetha S Rana H J Yoo et al ldquoFunctionalization ofcarbon nanomaterials for advanced polymer nanocompositesA comparison study between CNT and graphenerdquo Progress inPolymer Science vol 67 pp 1ndash47 2017

[3] S He N D Petkovich K Liu Y Qian C W Macosko and AStein ldquoUnsaturated polyester resin toughening with very lowloadings of GO derivativesrdquo Polymer Journal vol 110 pp 149ndash157 2017

[4] M Suominen P Damlin S Granroth and C KvarnstromldquoImproved long term cycling of polyazulenereduced grapheneoxide composites fabricated in a choline based ionic liquidrdquoCarbon vol 128 pp 205ndash214 2018

[5] J Wang H Jia Y Tang et al ldquoEnhancements of the mechanicalproperties and thermal conductivity of carboxylated acryloni-trile butadiene rubber with the addition of graphene oxiderdquoJournal of Materials Science vol 48 no 4 pp 1571ndash1577 2013

[6] C Wu X Huang G Wang et al ldquoHyperbranched-polymerfunctionalization of graphene sheets for enhanced mechanicaland dielectric properties of polyurethane compositesrdquo Journalof Materials Chemistry vol 22 no 14 pp 7010ndash7019 2012

[7] X She C He Z Peng and L Kong ldquoMolecular-level disper-sion of graphene into epoxidized natural rubber morphologyinterfacial interaction and mechanical reinforcementrdquo PolymerJournal vol 55 no 26 pp 6803ndash6810 2014

[8] S Keten Z Xu B Ihle and M J Buehler ldquoNanoconfinementcontrols stiness strength and mechanical toughness of beta-sheet crystals in silkrdquoNatureMaterials vol 9 no 4 pp 359ndash3672010

[9] M E Launey M J Buehler and R O Ritchie ldquoOn themechanistic origins of toughness in bonerdquo Annual Review ofMaterials Research vol 40 no 1 pp 25ndash53 2010

[10] A Gautieri M J Buehler and A Redaelli ldquoDeformation ratecontrols elasticity and unfolding pathway of single tropocolla-gen moleculesrdquo Journal of the Mechanical Behavior of Biomedi-cal Materials vol 2 no 2 pp 130ndash137 2009

[11] M Hayashi S Matsushima A Noro and Y MatsushitaldquoMechanical property enhancement of ABA block copolymer-based elastomers by incorporating transient cross-links into softmiddle blockrdquoMacromolecules vol 48 no 2 pp 421ndash431 2015

[12] B J Gold C H Hovelmann C Weiss et al ldquoSacrificial bondsenhance toughness of dual polybutadiene networksrdquo PolymerJournal vol 87 pp 123ndash128 2016

[13] M CR L M J YL S L and R K RT ldquoAdsorptionbehaviour of reduced graphene oxide towards cationic andanionic dyes Co-action of electrostatic and 120587 ndash 120587 interactionsrdquoMaterials Chemistry and Physics vol 194 pp 243ndash252 2017

[14] J Yuan H Zhang G Hong et al ldquoUsing metalndashligandinteractions to access biomimetic supramolecular polymerswith adaptive and superb mechanical propertiesrdquo Journal ofMaterials Chemistry B vol 37 no 1 pp 4809ndash4818 2013

[15] L Zhang L R Kucera S Ummadisetty et al ldquoSupramolecularmultiblock polystyrenendashpolyisobutylene copolymers via ionicinteractionsrdquo Macromolecules vol 47 no 13 pp 4387ndash43962014


[16] Z Tang J Huang B Guo L Zhang and F Liu ldquoBioinspiredengineering of sacrificial metalndashligand bonds into elastomerswith supramechanical performance and adaptive recoveryrdquoMacromolecules vol 49 no 5 pp 1781ndash1789 2016

[17] J Huang L Zhang Z Tang et al ldquoBioinspired design of arobust elastomer with adaptive recovery via triazolinedioneclick chemistryrdquo Macromolecular Rapid Communications vol38 no 7 pp 1600678ndash1600684 2017

[18] S Wu M Qiu Z Tang J Liu and B Guo ldquoCarbon nanodotsas high-functionality cross-linkers for bioinspired engineeringof multiple sacrificial units toward strong yet tough elastomersrdquoMacromolecules vol 50 no 8 pp 3244ndash3253 2017

[19] Y Y Mao S P Wen Y L Chen et al ldquoHigh performancegraphene oxide based rubber compositesrdquo Scientific Reportsvol 3 no 3 pp 2508ndash2514 2013

[20] W Wu C Wan S Wang and Y Zhang ldquoPhysical prop-erties and crystallization behavior of ethylene-vinyl acetaterubberpolyamidegraphene oxide thermoplastic elastomernanocompositesrdquoRSCAdvances vol 3 no 48 pp 26166ndash261762013

[21] S M Liff N Kumar and G H McKinley ldquoHigh-performanceelastomeric nanocomposites via solvent-exchange processingrdquoNature Materials vol 6 no 1 pp 76ndash83 2007

[22] D Luo F Wang B V Vu et al ldquoSynthesis of graphene-basedamphiphilic Janus nanosheets via manipulation of hydrogenbondingrdquo Carbon vol 126 pp 105ndash110 2018

[23] X Liu W Kuang and B Guo ldquoPreparation of rubbergrapheneoxide composites with in-situ interfacial designrdquo Polymer Jour-nal vol 56 pp 553ndash562 2015

[24] H Sun G-L Xu Y-F Xu et al ldquoA composite material ofuniformly dispersed sulfur on reduced graphene oxide aqueousone-pot synthesis characterization and excellent performanceas the cathode in rechargeable lithium-sulfur batteriesrdquo NanoResearch vol 5 no 10 pp 726ndash738 2012

[25] J Zhang Y Xu L Cui et al ldquoMechanical properties of graphenefilms enchanced by homo-telechelic functionalized polymerfillers via120587ndash120587 stacking interactionsrdquoComposites Part A AppliedScience and Manufacturing vol 71 pp 1ndash8 2015

[26] L Zhang R Jamal Q ZhaoMWang andTAbdiryim ldquoPrepa-ration of PEDOTGO PEDOTMnO

2 andPEDOTGOMnO

2

nanocomposites and their application in catalytic degradationof methylene bluerdquo Nanoscale Research Letters vol 10 pp 148ndash156 2015

[27] Z X Ooi H Ismail and A A Bakar ldquoA comparative study ofaging characteristics and thermal stability of oil palm ash silicaand carbon black filled natural rubber vulcanizatesrdquo Journal ofApplied Polymer Science vol 130 no 6 pp 4474ndash4481 2013

[28] H Lian S Li K Liu L Xu K Wang and W Guo ldquoStudy onmodified graphenebutyl rubber nanocomposites I Prepara-tion and characterizationrdquo Polymer Engineering amp Science vol51 no 11 pp 2254ndash2260 2011

[29] J R Potts D R Dreyer C W Bielawski and R S RuoffldquoGraphene-based polymer nanocompositesrdquo Polymer Journalvol 52 no 1 pp 5ndash25 2011

CorrosionInternational Journal of

Hindawiwwwhindawicom Volume 2018

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Materials Science and EngineeringHindawiwwwhindawicom Volume 2018


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Chemistry

Analytical ChemistryInternational Journal of


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Polymer ScienceInternational Journal of



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Journal ofEngineeringVolume 2018

Applied ChemistryJournal of


NanotechnologyHindawiwwwhindawicom Volume 2018

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High Energy PhysicsAdvances in

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

TribologyAdvances in



ChemistryAdvances in


Advances inPhysical Chemistry


BioMed Research InternationalMaterials

Journal of


Na

nom

ate

ria

ls


Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom


MGO

OH

OH

OH

OH OH

OH

OH

OH

OH

OH OH

OH

COOH

COOH

OH

OH

OH

OH

OH

O

O

O

OO

O

O

O

O

OO

O

HOHOHO

HOOC

O

OO

O

O

OO

OO

C

C

C

C

C

O

O

O

O

OO

OO

O

O

O

O O

OH

COOH

COOH

COOH

COOHCOOH

COOH

GO

75∘C

Figure 1 Preparation of polyethylene glycol graft modified graphene oxide

styrene butadiene rubber (SSBR) with triazolidinedione byclick chemistry and introduced the urezo groups to SSBRto provide hydrogen bonds thereby the sacrificial bondswere constructed in the system The tensile strength of themodified SSBR had been significantly enhanced to 764 MPawhich was higher than that of the pure SSBR Wu [18]used themaleic anhydride-modified polyisoprene rubber andaminomodified carbon nanodots to construct the networkof sacrificial bonds and used unsaturated bonds to constructthe chemically cross-linked network The tensile strengthapproached 305 MPa when the dosage of carbon nanodotswas only 3 phr which was stronger than that of the poly-isoprene rubber reinforced by 40 phr N330 carbon blackMao [19] added a kind of VPR into GOstyrene butadienerubber (SBR) system and constructed ionic bond interactionbetween pyridine group (positive) in the vinyl pyridine unitof VPR and oxygen-containing functional group (negative)on the surface of GO Wu [20] characterized the interfacialinteraction of VPRGO composites by the dielectric relax-ation spectra of the vulcanizates with different interactions(ionic bond hydrogen bond) The results revealed that thevelocity of segmental relaxation and interfacial relaxation ofVPRGO composite bonded by ionic bond was higher thanthat of composites bonded by hydrogen bond indicating thatthe internal interaction of GOVPR composites bonded byionic bond was stronger Li [21] found that the dissociationenergy of hydrogen bond in polyurethane was about 167kJmol In general the bonding energy of C-C covalent isover 300 kJmol It means that the hydrogen bond is likely tobe destroyed during the strain process and additional strainenergy will be consumed so the strength and toughness ofmaterial are guaranteed

In the present paper graphene oxide was grafted withpolyethylene glycol 600 by means of the reaction betweenthe carboxyl groups on the surface of graphene oxide andthe hydroxyl groups at the end of polyethylene glycol andthen added to PUR The grafted graphene oxide reinforcedthe PUR significantly through hydrogen bonds on the filler-rubber interfaces Additional strain energy was dissipatedby destructing the hydrogen bond sacrificial unit duringthe strain process thereby the strength and toughness wereimproved simultaneously

2 Experiment

21 Materials Polyurethane rubber (PUR type of HA-5)was purchased from Shanxi Institute of Chemistry Indus-try China Graphene oxide (GO lamellar size of 10-50120583m layers of 6sim10) was purchased from SuZhou TanfengCo Ltd China Polyethylene glycol (PEG AR number-average molecular weight of 600) 4-dimethylaminopyridine(DMAP AR) N N-dicyclohexylcarbodiimide (DCC AR)and dicumyl peroxide (DCP AR)were purchased from SigmaAldrich Company USA All materials were used directlywithout further treatment

22 Sample Preparation

221 Preparation ofGraedGrapheneOxidewith PolyethyleneGlycol 600 mg GO and 350 ml toluene were added to a 500ml single-neck flask at room temperature and dispersed byultrasound for 30minutesThen 20 g PEG 058 gDMAP and119 g DCCwere added to the flask successively and dispersedby ultrasound for 30 minutes thereafter the content wasstirred by magnetic force for 24 h at temperature 75∘C Thereaction product was filtered by polytetrafluoroethylene filterpaper with 02 120583m aperture Filter cake was washed with 50ml of toluene and 700ml of deionized water in turn and thenwas dried in vacuum oven at 60∘CThe product was denotedas MGOThe preparation process was depictured in Figure 1

222 Preparation of PURMGO A mill (type of XK-150Zhanjiang Machinery Factory China) was used to mix theraw materials The roller gap of mill was adjusted to about01 mm then PUR GO (or MGO) and DCP were added inturn After each addition the PUR compounds were side-cutboth sides in turn 5 times and then triangle-packed 5 timesand thin-passing 5 times finally the rubber compounds wererolled into 2 mm sheet After being parked for 24 h the sheetwas vulcanized on a press (type of KSH-R100 DongguanKesheng Industrial Co Ltd China) with 16 MPa for t

90+2

min at 175∘C The mass ratio of PUR DCP was 100 2 Theamount of GO or MGO was variable For example if theamount of MGO was 05 phr the sample was marked asPURMGO-05


















GOMGO

80

85

90

95

100

Tran

smitt

ance

()


(a)

PEG

20

40

60

80

100

Tran

smitt

ance

()


(b)

G-bandD-band

Inte

nsity

(au

) MGO

GO


(c)

GOMGO

40

50

60

70

80

90

100

Mas

s (

)

200 400 600 800 10000Temperature (∘C)

(d)

GOMGO

Inte

nsity

(au

)

10 20 30 40 50 6002 (∘)

(e)








320 340 360 380 400 420300Temperature (∘C)

400 420 440 460 480380Temperature (∘C)

0

20

40

60

80M

ass (

)

20

40

60

80

100

Mas

s (

)

200 400 600 8000Temperature (∘C)

0

20

40

60

80

100

Mas

s (

)









0

1000

2000

3000

4000

5000

6000

7000

(MPa

)

(a)



minus02

00

02

04

06

08

10

12

Tan

(b)









20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1


00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()


(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)


















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





















GOMGO

80

85

90

95

100

Tran

smitt

ance

()


(a)

PEG

20

40

60

80

100

Tran

smitt

ance

()


(b)

G-bandD-band

Inte

nsity

(au

) MGO

GO


(c)

GOMGO

40

50

60

70

80

90

100

Mas

s (

)

200 400 600 800 10000Temperature (∘C)

(d)

GOMGO

Inte

nsity

(au

)

10 20 30 40 50 6002 (∘)

(e)








320 340 360 380 400 420300Temperature (∘C)

400 420 440 460 480380Temperature (∘C)

0

20

40

60

80M

ass (

)

20

40

60

80

100

Mas

s (

)

200 400 600 8000Temperature (∘C)

0

20

40

60

80

100

Mas

s (

)









0

1000

2000

3000

4000

5000

6000

7000

(MPa

)

(a)



minus02

00

02

04

06

08

10

12

Tan

(b)









20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1


00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()


(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)


















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





GOMGO

80

85

90

95

100

Tran

smitt

ance

()


(a)

PEG

20

40

60

80

100

Tran

smitt

ance

()


(b)

G-bandD-band

Inte

nsity

(au

) MGO

GO


(c)

GOMGO

40

50

60

70

80

90

100

Mas

s (

)

200 400 600 800 10000Temperature (∘C)

(d)

GOMGO

Inte

nsity

(au

)

10 20 30 40 50 6002 (∘)

(e)








320 340 360 380 400 420300Temperature (∘C)

400 420 440 460 480380Temperature (∘C)

0

20

40

60

80M

ass (

)

20

40

60

80

100

Mas

s (

)

200 400 600 8000Temperature (∘C)

0

20

40

60

80

100

Mas

s (

)









0

1000

2000

3000

4000

5000

6000

7000

(MPa

)

(a)



minus02

00

02

04

06

08

10

12

Tan

(b)









20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1


00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()


(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)


















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls








320 340 360 380 400 420300Temperature (∘C)

400 420 440 460 480380Temperature (∘C)

0

20

40

60

80M

ass (

)

20

40

60

80

100

Mas

s (

)

200 400 600 8000Temperature (∘C)

0

20

40

60

80

100

Mas

s (

)









0

1000

2000

3000

4000

5000

6000

7000

(MPa

)

(a)



minus02

00

02

04

06

08

10

12

Tan

(b)









20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1


00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()


(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)


















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls







0

1000

2000

3000

4000

5000

6000

7000

(MPa

)

(a)



minus02

00

02

04

06

08

10

12

Tan

(b)









20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1


00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()


(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)


















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls






20 40 60 80 1000Strain ()

00

02

04

06

08

10

12

Stre

ss (M

Pa)

(a)

Cycle 1


00

02

04

06

08

10

12

Stre

ss (M

Pa)

20 40 60 80 1000Strain ()


(b)

20 40 60 80 100 1200Storage Time (min)

84

86

88

90

92

94

96

98

100

７2Ｈ＞

７1ＭＮ

()

PURMGO-10 60∘C

PURGO-10 25∘C

PURMGO-10 25∘C

PURGO-10 60∘C

(c)


100 200 300 400 500 600 7000Strain ()

0

5

10

15

20

25

30St

ress

(MPa

)

(d)


















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls















0)

4 Conclusions



TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls





TM3030 N D42 times500 200 m

(a)

TM3030 N D43 times500 200 m

(b)

TM3030 N D43 times500 200 m

(c)

TM3030 N D44 times500 200 m

(d)

TM3030 N D44 times500 200 m

(e)


(f)



Data Availability








0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls






0 1 2 3 0lt lt lt


Acknowledgments


References




























2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls
















2 andPEDOTGOMnO

2







Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls






Advances in



Journal of

Chemistry















Journal of





Volume 2018









Journal of


Na

nom

ate

ria

ls




Documents

Enhancing Mechanical and Thermal Properties of ...downloads.hindawi.com/journals/apt/2019/2318347.pdf · ReseachArticle Enhancing Mechanical and Thermal Properties of Polyurethane