Jhaiquashia Peterson, Muneer Shaik, Dr. Ed Kolodka, Dr. Guodong DuDepartment of Chemistry, University of North Dakota, 151 Cornell Street, Grand Forks, ND 58202

BACKGROUND

OBJECTIVES• Perform ring-opening polymerization of beta-

butyrolactone utilizing amido-oxazolinatezinc complexes as catalysts and diolinitiators to increase the chain length oflinear polyesters with degradable properties.

• Employ nuclear magnetic resonance (NMR),thermal gravimetric analysis (TGA), anddifferential scanning calorimetry (DSC) tocharacterize the polymer products

• To achieve the goal, a Schlenk line was usedfor optimization of inert conditions.

• Dr. Edward Kolodka• Dr. Alena Kubatova• Dr. Frank Bowman • UND Departments of Chemistry and

Chemical Engineering

This material is based upon work supported by the National Science Foundation REU under Grant No. CHE 1460825. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation

1H NMR BBL + 1,4 Cyclohexanediol in CDCl3

1H NMR BBL + 1,4 Benzenedimethanol in CDCl3

• Abbina, S.; Chidara, V. K. ChemCatChem2017, 9 (7), 1343-1348.

• Abbina, S.; Du, G. ACS Macro Lett. 2014, 3, 689-692.

• Binda, P. I.; Abbina, S.; Du, G. Synthesis 2011, 2609-2618.

• Ebrahimi, T.; Aluthge, D. C.; Hatzikiriakos, S. G.; Mehrkhodavandi, P. Macromolecules 2016, 49, 8812-8824.

InterdisciplinaryRenewable & EnvironmentalChemistry REU

• Plastics are commonly produced frompetroleum-based materials.

• These structures of these materials typicallydo not break down easily, so they accumulatewithin the environment creating pollution.

• BBL is a petroleum-derived monomer whosestructure contains an ester bond

• Ester bonds are weaker than the alkane andether bonds that make up most commonlyused petroleum monomers and more likely tobreak down.

1:1:1 substrate: catalyst: initiator: BBL

DCMHexanes

PurificationReaction set up Synthesis

Reaction Approach

Ø With initiator 1:1:200

Table 1. Results of BBL ROP

Ø 1H NMR spectrum shows the expected coupling and splitting of the polymer chain protons as well as the initiator’s presence and the hydroxyl polymer end groups.

O-ringjoints

Main trap

To diffusion

pump

O-ringjoints

O-ringjoints

End cap

End cap w/ Teflon

stopcock

Pre-trap

Apparatus is connected here using O-ring joints

8 mm bare Teflon stopcocks

Hook up inert or

reactant gas here

O-ring joints for connection to

vacuum, nitrogen gauges

MATERIALS AND METHODSOptimized Reaction

O

O

Toluene, 100oC O

O

n

Catalyst

Ø Without initiator 1:200

Catalyst – Amido-Oxazolinate Zinc Complexes

RESULTS AND DISCUSSION

Initiators – Alcohols

aAll reactions were performed in toluene (4 mL) at 100 °C for 90 mins with a catalyst L10: initiator: monomer ratio of 1:1:200. bDetermined by measuring the intensities of peaks on 1H NMR spectroscopy.

CONCLUSION• Amido-oxazolinate complexes are active and

sufficient for production of high molecular weight polymers.

• Diol initiators successfully reacted and increased chain length of the polymer.

• Isolated pure polymers are characterized and the linear structure of the polymer confirmed by 1H NMR.

Future Work• Analyze initiator effect on molecular weight

using gel permeation chromatography (GPC).

• Analyze polymer properties using DSC and TGA to find glass transition temperature (Tg) and melting temperature (Tm).

Figure 2. 1H NMR Spectrum of Pure Reaction Mixture of ROP of β-BBL with a initiator-d and catalyzed by L10

Figure 1. 1H NMR Spectrum of Pure Reaction Mixture of ROP of β-BBL with a initiator-c and catalyzed by L10

ACKNOWLEDGEMENTS

REFERENCES

Ø 1H NMR spectrum shows the expected coupling and splitting of the polymer chain protons, as well as the presence of aromatic protons from the initiator and the hydroxyl polymer end groups.

Ø Ratio of moles of initiator to zinc catalyst necessary to achieve optimal reaction conditions

N N

O

Ph

R:N(SiMe3)2

N N

O

N

O

N N

O

Zn Zn Zn ZnR R RR

R:N(SiMe3)2 R:N(SiMe3)2 R:N(SiMe3)2L14 L15

N

L10L9

F3C

CF3R:N(SiMe3)2

N N

O

Zn

R

L6

OH

OH

OH

OH

HO OH

OH

OHO OHO

OHOH

a b c d

e f

Entry Initiators Mn (calcd) Mn (NMR)b Conv (%)

1 a 17326 17428 100

2 b NR NR NR

3 c 17334 17452 100

4 d 17359 18884 100

RING-OPENING POLYMERIZATION OF BETA-BUTYROLACTONE UTILIZINGAMIDO-OXAZOLINATE ZINC COMPLEXES TO OBTAIN DEGRADABLE POLYMERS