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Science and Technology of Polymers(2nd Cycle)
Courses
Reactions of Polymers and Production of Polymers
and
https://fenix.ist.utl.pt/disciplinas/ctp364/2012-20 13/2-semestre
Coordination:Pedro Teixeira Gomes
Departamento de Engenharia Química
Instituto Superior Técnico
Reactions of Polymers and Production of Polymers(3rd Cycle)
https://fenix.ist.utl.pt/disciplinas/rppp-2/2012-20 13/2-semestre
STRUCTURE OF THE SUBJECT(2012-13)
Block 1 – Fundamentals of Macromolecular ChemistryDefinitions, nomenclature and classifications. Macr omolecular structures and their characterization. Solutions of polymers. Defin ition and determination of average molecular weights and molecular weight dist ributions.
12 hours13/02 – 28/02
Pedro T. Gomes
Block 2 – Polymerization Reactions and Reactions of PolymersNon-vinyl polymers (step polymerization). Vinyl poly mers (chain polymerization): radical polymerization ; copolymeriza tion; cationic polymerization; anionic polymerization; coordination polymerization; chemical reactions in vinyl polymers. Controlled/living poly merization .
16 hours06/03 – 04/04
Pedro T. Gomes
Block 3 – Polymer Melts and Polymers in the Solid St atePolymer melts: non-newtonian behaviour, visco-elast icity, rheological aspects of processing. Polymers in the solid state: amorpho us state and glass transition; crystalline state and melting. Techniqu es of characterization of thermal, structural and morphological properties. E lastomers. Mechanical properties and techniques of thermo-mechanical char acterization. Electrical and optical properties.
12 hours10/04 – 24/04
Jorge Morgado
Block 4 – Production of PolymersReactive polymers with industrial importance. Produ ction of composites. Main transformation processes (special emphasis on chemical aspects of processing). Chemical aspects in the main applicati ons of polymers. Polycondensation and polyaddition reactors. Dimensi oning of polymerization reactors. Thermoplastic formulation. Durability and degradation of polymers.
16 hours02/05 – 23/05
João C. Bordado
BIBLIOGRAPHY
- M. P. Stevens, "Polymer Chemistry - An Introduction", 3rd ed., Oxford Univ. Press, 1999 (DEQ library: 2 nd ed., 1990)
- G. Odian, “Principles of Polymerization”, 4th ed., Wiley-Interscience, N.Y., 2004(Pedro T. Gomes’ office)
- F. Rodriguez, “Principles of Polymer Systems”, Taylor & Francis, 4th ed., N.Y., 1996.(DEQ library: 2nd ed., McGraw-Hill, 1983)
- J. K. Fink, “Reactive Polymers Fundamentals and Applications - A Concise Guide to Industrial
Main Bibliography
Polymers”, William Andrew Publishing, 2005. (J. C. Bordado’s office)
- M Michalovic, K. Anderson, L. Mathias, “The Macrogalleria”, site of Polymer Site LearningCenter (da University of Southern Mississippi) (http://www.pslc.ws/macrog.htm)
- P. Munk, T.M. Aminabhavi, "Introduction to Macromolecular Science", 3rd ed., John Wiley &Sons, N.Y., 2002. (DEQ library : 1st ed., 1989)
- F. Billmeyer, "Textbook of Polymer Science", Wiley-Interscience, 3rd ed., N.Y., 1984.(DEQ library)
Other Bibliograhy
- “Encyclopedia of Polymer Science and Technology”, 3rd ed., Wiley-Interscience, 2004 (DEQ library )
- J. C. Salamone, Ed., “Polymeric Materials Encyclopedia”, John Wiley, 1996.(DEQ library )
- “Comprehensive Polymer Science”, Pergamon Press, Oxford, 1989(Complexo Interdisciplinar, CQE -Group II room )
- “Polymer Handbook”, Wiley-Interscience, 4th ed., John Wiley & Sons, 2003
Encyclopedias, Handbooks
- “Polymer Handbook”, Wiley-Interscience, 4 ed., John Wiley & Sons, 2003(DEQ library )
ASSESSMENT(2012-13)
CTP – Science and Technology of Polymers (2nd Cycle)
- Continuous assessment: 4 tests (at the end of eac h of the 4 blocks) and/or final exam(2 oportunities: 4 tests + 1 exam or 2 exams)
RPPP – Reactions of Polymers and Production of Polymers (3rd Cycle)
- Continuous assessment: 4 tests (at the end of eac h of the 4 blocks) and/or final exam(2 oportunities: 4 tests + 1 exam or 2 exams)(2 oportunities: 4 tests + 1 exam or 2 exams)
Alternatively:
- Writing up 1 monography (máx. 10-20 pages) in each of Blocks 2 and/or 3, to be delivered until the date of the corresponding test. Oral discussion.
Tests (provisional dates): Wednesady, 05/03 ( Block 1 Test ), 18 hTuesday, 09/04 ( Block 2 Test ), 18 hTuesday, 30/04 ( Block 3 Test ), 18 h
1st Exam: Wednesday, 05/06 (and also Block 4 Test ), 11:30 h 2nd Exam: Friday, 28/06, 11:30 h
Bloco 1
Fundamentals of Macromolecular Chemistry
Pedro Teixeira Gomes
MILESTONES IN THE USE OF STRUCTURAL MATERIALS BY MA NKIND
HISTORY
MODERNAGE
STONEAGE
PRE-HISTORY
METALSAGE
PROTO-HISTORY
ANCIENTAGE
MIDDLEAGE
CONTEMPORARYAGE
CEMENTCONCRETE
WOODCHIPPED STONEPOLISHED STONE
COPPER (4000 AC)TINBRONZEIRONCERAMICS
GLASS(1500 BC)
METALALLOYS
POLYMERS
1496 – Colombus (rubber balls brought in his 2nd expedition to America; the Mayans already used it for centuriesand the tree was called caoutchouc)
1763– rubber dissolved in turpentine oil is sold as a glue in France
1748– Charles Marie de La Condamine, description of latex collected from “Hevea Brasiliensis”(native rubber tools)
ORIGINS OF RUBBER TECHNOLOGY
1763– rubber dissolved in turpentine oil is sold as a glue in France
1770– rubber is used as an eraser to delete pencil(Priestley)
1791-1823–Mackintosh clothing, made with natural rubber (McIntosh)
1844– Goodyear vulcanizesrubber with sulphur
1906– Harries polymerizes isoprene with sodium
1907– Hofman (Bayer) uses 2,3-dimethylbutadiene to make methyl rubber
1870– Hyatts, cellulose nitrate + camphor = CELLULOID (billiard balls (coating), table tennis balls)
1892– Cross e Bevan, cellulose acetate and xanthate →→→→ viscose rayon fibres
1907– Baekeland, first phenol-formaldheyde resin →→→→ BAKELITE
1846– Schonbein, first synthetic plastic →→→→ cellulose nitrate
ORIGINS OF PLASTIC TECHNOLOGY
- CELLULOSE NITRATE- CELLULOSE ACETATE
1918– Only 3 plastics industries : - CELLULOSE ACETATE- BAKELITE
OHO
HOOH
OH
OH
OO
HOOH
O
OH
O
HOOH
OH
O
HOOH
O
OH
- n H2O
CELLULOSEββββ-GLUCOSE
UNTIL 1918 – Polymers were thought to be aggregates of small molecules associated bysecondary forces (Van der Waals)
CONCEPT OF MACROMOLECULE (POLYMER)
1918 - 1920– Staudingerproposed that in many macromolecules the repeating units were covalently bonded→→→→ High molecular weight molecules.
• Synthesis of poly(ethyene oxide), poly(methylene oxide), polystyrene (1920-1930)
• Notion of molecular weight distribution. Viscometric method for the determinationof molecular weightsof molecular weights
1929– Meyer e Mark explained the vulcanization of rubber. Study of polymers by X-rays
1931– Carothers, first polycondensation reactions (polyesters, polyamides) leading to high molecular weight polymers
MACROMOLECULES
AGGREGATES – of small molecules, bonded by Van der Waals forces
POLYMERS – Long molecules containing an unit which is repeated throughout the chain. The repeating repeated throughout the chain. The repeating units are covalently bonded to each other
SYNONIMS: PLASTICS, RESINS, ETC. (according to their properties and/or physical appearance)
DEFINITIONS
POLYMER – Greek →→→→ Poly + mer(many) (parts)
MONOMER – Greeek →→→→ Mono + mer(one) (part )
OLIGOMER – Greek →→→→ Oligo + mer(few) (parts)
REPEATING UNIT – group of atoms (from the monomers) that
CH2 CH CH2
n
CH3CH2 CH2
REPEATING UNIT – group of atoms (from the monomers) that repeat throughout the polymer chain
part ≡≡≡≡ repeating unit≡≡≡≡ monomeric unit
END GROUPS – structural units situated at the polymer chain ends
End Groups
Repeating Unit
C C
H
H
H
H
n CH2 CH2n
Ethylene
Monomer
Poly(ethylene) ≡≡≡≡ Polyethylene
Polymer
NOMENCLATURE – According to IUPAC, the polymers are named by its monomer as:poly(monomer)
Example: The molecular weight of a polyethylene with DP=5000 is:
M = M RU ×××× DP= 28 ×××× 5000 = 140 000
MRU = repeating unit molecular weight =28
n = Degree of polymerization (DP) – total number of repeating units (RU), including terminal groups
it is related with:
CHAIN LENGTH MOLECULAR WEIGHT (M)
When DP is high, the importance of end groups is irrelevant and we should write:
or
When DP is low –oligomer - the importance of end groups is relevant. We should write :
MY Y'n
M Mn
The synthetic polymers (and oligomers) generally have chains of variable length (i.e. a molecular weight
distribution).
MONODISPERSE POLYMERS – a single chain length
POLYDISPERSE POLYMERS– several chain lengths ≡≡≡≡ molecular weight distribution
Then we should define an AVERAGE DEGREE OF POLYMERIZATION (DP)
TYPES OF POLYMERIZATION
•••• STEP POLYMERIZATION (Polycondensation)
HO OH + CCO
OH
O
HO
HO O CC
O
O
O
Hn
n n
+ (2n-1) H2O
Diol Diacid
•••• CHAIN POLYMERIZATION (Polyaddition)
n
Polyester
There can be elimination of small molecules: H2O, ROH, HCl, ...
CH
Xn CH
X
CH2n
CH2
There is no elimination of small molecules
The ultimate mechanical properties of any polymer result from a balance of:
• MOLECULAR WEIGHT / MOLECULAR WEIGHT DISTRIBUTION
• CHEMICAL STRUCTURE
A polymer must attain a certain value of molecular weightfor possessing
useful mechanical properties, but that molecular weight depends very much
on the molecular structure of the polymer.on the molecular structure of the polymer.
STRUCTURE and MOLECULAR WEIGHT condition the INTERMOLECULAR FORCES:
• Hydrogem Bonds
- permanent dipole - permanent dipole (Keesom)
• Van der Waals Forces: - permanent dipole-induced dipole (Debye)
- instantaneous dipole-induced dipole (London)
• Ion-dipole Forces
•••• PRIMARY STRUCTURE – resulting from the covalent bonds between repeating units
•••• SECONDARY STRUCTURE – resulting from the spatial arrangement of the main chain segmentsaccording to regular patterns, which are dictated by stereochemistry (most stable conformations) or hydrogen bonds (αααα-helix or ββββ-sheet)
•••• QUATERNARY STRUCTURE – resulting from the interaction between different chains
•••• TERTIARY STRUCTURE – resulting from the whole tridimensional structure of the chain, which is conditioned by intramolecular forces and hydrogen bonds between distant segments of the chain
PRIMARY STRUCTURE
PRIMARY
• LINEAR
• CYCLO-LINEAR
• BRANCHED
• COPOLYMERS
resulting from the covalent bonds between repeating units
PRIMARYSTRUCTURE
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
• LINEAR
• CYCLO-LINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
CARBON CHAIN POLYMERS
• Polymeric hydrocarbons (C=C chain polymerization)
- Nomenclature- some important polymers
•••• LINEAR POLYMERS- CARBON CHAIN POLYMERS- HETEROATOM CHAIN POLYMERS- INORGANIC CHAIN POLYMERS
PRIMARY STRUCTURE
• Polymeric hydrocarbons (C=C chain polymerization)
• POLYETHYLENE (Polyethene; Polymethylene (IUPAC))
CH2n CH2 CH2n
CH2
- Electrical insulating- Piping- Packing (films)- Bags- Agriculture (gree-houses)
•••• Low Density (branched- radical polymerization)•••• High Density (linear – coordination polymerization)
PE
• POLYPROPYLENE (Polypropene; Poly(1-methylethylene) (IUPAC))
- Fibres (ropes, carpets)- Packing (films and semirigids)- Piping
CH
H3Cn CH
CH3
CH2n
CH2
High density (coordination)PP
• POLY(ISOBUTYLENE) (Poly(isobutene); Poly(1,1-dimethylethylene) (IUPAC))
- Component of BR rubber- Inner tubes (bikes)- Motor gaskets- Electrical insulating
C
H3Cn C
CH3
CH2n
CH2
CH3H3C
• POLYBUTADIENE
n CH
HC
CH2n
CH2
HCH2C
CH CH2
1 2
3 4
HCH2C
CH CH2CH
H2C
CH
CH2
1,2-POLY(1,3-BUTADIENE)(Poly(1-vinylethylene) (IUPAC))
SYNTHETIC RUBBER
HCH2CH2C CH2 nn
TRANS-1,4-POLY(1,3-BUTADIENE)(trans-Poly(1-butenylene) (IUPAC))
CIS-1,4-POLY(1,3-BUTADIENE)(cis-Poly(1-butenylene) (IUPAC))
HCH2C CH CH2
n
CHHC CH2 CH2
n
≡
nCH CH2
CH2C1 2
3 4
CH2C
CH CH
C
H2C
CH
CH2n
CH3H3C
CH3
• POLY(ISOPRENE)
1,4-CIS
NATURALRUBBER
- Hevea Brasiliensis- Guayule
GUTTA-PERCHA
Hard material :low percentage
of 1,2 and 3,4 units CH CH2 n
1,4-TRANS
Hard material :- Insulator- Golf balls (old ones)
• POLYSTYRENE (Poly(1-phenylethylene) (IUPAC))
- General use plastic- Thermal insulator- Packing of fragile goods- Engineering plastic (syndiotactic)
CHn CH CH2n
CH2
of 1,2 and 3,4 units
• Polymers containing halogen substituents
• POLY(VINYL CHLORIDE) (PVC; Poly(1-chloroethylene) (IUPAC))
- Piping- Flooring- Packing (bottles, “tupperware”, etc. )
- Hoses, waterproof goods,seat covers
CH
Cln CH
Cl
CH2n
CH2
When additivated(esters, epoxides, etc.)
Radical polymerization (emulsion)
• POLY(TETRAFLUOROETHYLENE) (PTFE; TEFLON; Poly(difluoromethylene) (IUPAC))
- Insoluble- Thermally stable
- Frying pans coating (non-sticking material)-Kitchen tools - Waterproof material
CF2n CF2 CF2n
CF2
n
CH CH2
CH2C
Cl
CH2C
CH CH2 n
Cl
• POLY(CHLOROPRENE) (Poly(neoprene); Poly(1-chloro-1-butenylene) (IUPAC))
- Best hydrocarbon-proof rubber- High vacuum applications
1,4-TRANS
• Polymers with polar side groups
low percentageof 1,4-cisand 3,4 units
• POLY(METHYL ACRYLATE) (Poly(1-methylcarboxylatoethylene) (IUPAC))
- Rubber (without commercial application)
CH
C
n CH
C
CH2n
CH2
O
OCH3 O OCH3
• POLY(METHYL METHACRYLATE) (Plexiglas; Perspex; Poly(1-methyl-1-methylcarboxylatoethylene) (IUPAC))
- Highly transparent- Glasses for airplanes and shops- Good resistance to acids and bases
C
C
n C
C
CH2n
CH2
O
OCH3 O OCH3
H3C CH3
• POLY(HYDROXYE THYL M ETHA CRYLATE) (Poly-HEMA; Poly(1-methyl-1-hydroxyethylcarboxylatoethylene) (IUPAC))
- Swells with water → Gel (35% water)- Elastic and strong Cn C CH2CH2
H3C CH3
- Elastic and strong - Contact lenses andother biomedical
applications
C
C
n C
C
CH2n
CH2
O
OCH2CH2OH O OCH2CH2OH
• POLY(ACRYLIC ACID) • POLY(METHACRYLIC AC ID)
R= HR= CH3
- Polyelectrolyte- Soluble in basic medium
C
C
n C
C
CH2n
CH2
O
OH O OH
R R
• POLY(SODIUM ACRYLATE)
- Polyelectrolyte- Super-absorbent (babby nappies, etc.)- Agriculture
CH
C
n CH
C
CH2n
CH2
O
O- O O- Na+Na+
• POLYCYANOMETHYLACRYLATE) (Poly(1-cyano-1-methylcarboxylatoethylene) (IUPAC))
C C
N N
• POLY(ACRYLONITRILE) (PAN; Poly(1-cyanoethylene) (IUPAC))
- Acrylic Fibres (Orlon)- Insoluble in the majority of solvents- Precursor to carbon fibres
CH
Cn CH
C
CH2n
CH2
NN
- Super-gluesC
C
n C
C
CH2n
CH2
O
OCH3 O OCH3
• POLY(VINYL ALCOHOL) (Poly(1-hydroxyethylene) (IUPAC))
- Water solubleCH CH2
n
OH-CH CH2
n
CH
O
n CH
O
CH2n
CH2
C R
O
C
O
R
• POLY(VINYL ACETATE) • POLY(VINYL BUTYRAT E)
R= CH3R= CH2CH2CH3
- Flexible transparent films- Photographic films (old ones)
- Water soluble- PolyelectrolyteOH
nO
n
C
O
R
Poly(vinyl acetate)
• POLY(VINYL PYRROLIDONE) • POLY(VINYL CARBAZOLE)
- Biocompatible; contact lenses (with “cross-links”)
CH
Nn CH
N
CH2n
CH2
OO
CH
N
n CH
N
CH2n
CH2
- Used in Xeroradiography
HETEROATOM CHAIN POLYMERS
Normally prepared by: 1) Polycondensation;2) Ring Opening Polymerization of heterocyclic monomers
• Polyeters
• POLY(OXYMETHYLENE) (POM; poly(methylene oxide); poly(oxymethylene) (IUPAC))
- Hard and strong material- Good thermal stability- Engineering plastic(it replaces metals in light and medium dutyapplications)
C
H
n CH2 On
O
HH+
applications)
• POLY(ETHYLENE OXIDE) (Poly(ethyleneglycol); PEG; PEO; Poly(oxyethylene) (IUPAC))
- Water soluble- Ionic conductor
H2Cn CH2 CH2 On
CH2
OH+ (B-)
• Polyesters
• POLY(ETHYLENE TEREPHTHALATE) (PET; Poly(oxyethylenoxyterephthaloyl) (IUPAC))
- Main polymer of polyester textiles (textile fibres)- Beverage bottles
CH2
HOn CH2
OH+ C C
O
OH
O
HO
-2n H2OO CH2 CH2 On C
O
C
O
n
ethyleneglycol terephthalic acid(Cyclolinear polymer)
PET
- Beverage bottles- Engineering plastic (mould construction)
CH2C C
O
OH
O
HO
nx
H3C C O
O
C CH3
O
n +- 2n CH3COOH
CH2C Cx
O
O O
n
CC
O
O
O
n
- Resistant fibres
acetic anhydride diacid
• Polyanhydrides
- Manufacture of organic lenses- Safety glass- Beverage bottles containers
diolphosgene
O C O C
CH3
CH3
O
n
• Polycarbonates
• Polyamides
CO On
O
HO OHn n+ C
O
Cl Cl
-2n HCl
+C C
O
OH
O
HO
-2n H2On C
O
C
O
NH
n
NHH2N NH2
terephthalic acid p-phenylenediamine KEVLAR
- Impact resistant fibres (bullet-proof vests, tire inner lining, sport objects, etc.)
- Texteis
εεεε-caprolactam Poly(εεεε-caprolactam) ≡ NYLON 6 ≡ Poly(imino(1-oxahexamethylene)) (IUPAC)
NH
O
CH2NH C5
O
n
H+
CH2N Nn3
+ CH2NH NH3
C C O
n
OOn
CNH NHC
O
CO C O
O
O
O
HO OH
O
- Elastic fibres (aliphatic)- Varnishes (aromatic)- Elastomers- Thermal insulating- Packing- Pillows, mattresses, etc.
diol Polyurethane
• Polyurethanes
diisocianate
- Pillows, mattresses, etc.
• Polyureas
- Properties similar to polyurethanes
diamine
CNH NHn
O
H2N NH2n n+ C
O
Cl Cl
-2n HCl
phosgenePolyurea
• Poly(isocyanates)
B-
Nn C OR N C
O
R n
• Polymers containing sulphur in the main chain
RubbersCH2 Sbx n
Poly(alkylene poly(sulphide))
- Rubbers
O C O
CH3
CH3 n
S
O
O n
- High temperatures resistance- Electrical insulator- Materials for high precision moulding
Poly(sulfone)
INORGANIC CHAIN POLYMERS
• Polymeric sulphur
- Elastic material1) ∆∆∆∆ (170ºC)
n S82) quenching
S S S S2n
Reversible Reaction !
• Poly(siloxanes) (Silicones)
Si ClCl
R
n + n H2O-2n HCl
Si O
R R= - alkyl- cyanoalkyl- perfluoroalkyl
R
2
Rn
- Rubbers (-30 to 200ºC) (high molecular weight)- Oils (low molecular weight)
- perfluoroalkyl- phenyl
Si ClCl
R
R'
nNa, ∆∆∆∆
Si
R
R' ntolueno
- 2n NaCl
• Poly(silanes)
- Used as photoresists(Si-Si bond sensitive light)
The -Cl atoms can be substituted by -OR, -CF3, -NR2 groups
• Polyphosphazenes
- Good chemical resistance- Good thermal resistance- Specialty rubbers, films
P N
Cl 3n
N
PN
P
NP
Cl Cl
Cl
Cl
Cl
Cl
Cl∆∆∆∆
• LINEAR
• CYCLOLINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
•••• CYCLOLINEAR POLYMERS- WITH ALTERNATING CYCLIC-LINEAR FRAGMENTS- WITH BONDED RINGS- WITH FUSED RINGS
• Polymers with alternating cyclic-linear fragments
• POLY(p-PHENYLENE OXIDE) (PPO; poly(oxy-2,6-dimethyl-1,4-phenylene) (IUPAC))
CH3
OH
CH3
O
n
n + n/2 O2 + n H2Oamina
Cu2+
- Hard polymer- Engineering plastic (easy to be machined → article parts)
CH3 CH3
• POLY(VINYLACETAL) AND • POLY(V INYLBUTYRAL)
- Used In the manufacture of safety laminated glasses (car windscreens, etc.)
CH
OH
CH2n
R C
O
H
+- n H2O
CH CH2 CH CH2
O OCH
R
n/2n/2
R= HR= CH2CH2CH3
• CYCLIZATION OF POLY(METHYLVINYLKETONE)
- n H2OCH CH2 CH CH2
n
O CH3 O CH3
CHCH2
CH CH2n
H3C CH O
Poly(methylvinylketone) Aldol condensation
• Polymers with bonded rings
• POLY(p-PHENYLENE) (poly(1,4-phenylene) (IUPAC))
C
O
C C
O
C
O
O
O
O
H2N NH2+- 2n H2O
C
N
C C
N
C
O
O
O
O
n
n n
• POLY(IMIDES)
Pyromelytic dianhydridep-phenylenediamine
- Very hard polymer; - High melting point; - Thermally stable; - Insulating varnishes; - Parts of airplane motors
nAlCl 3
nCuCl2
- Good electrical conductor (when doped)
• Polymers with fused rings - (Ladder Polymers)
• POLY(PHENYLSILSESQUIOXANE)
- Soluble in the majority of organic solvents
Si ClPh
Cl
Cl
n + n H2O- n HCl
Si O
Ph
O
Sin
O
Ph
O
Si SiO O
Ph Phn
OH-
- Soluble in the majority of organic solvents
C
O
C C
O
C
O
O
O
O
+ - 2n H2On n
NH2
NH2H2N
H2N
N
C
N N
C
N
CC
C
N
C
N
OOO
n
• POLY(IMIDAZO PYRROLONE)
• CYCLIZATION OF POLYACRYLONITRILE
- Very hard polymers- Intermediates in the synthesis of carbon fibres
(by pyrolisis at very high temperatures)
• LINEAR
• CYCLOLINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
•••• BRANCHED POLYMERS
LINEAR
• • •
•
• •• • • •
• ••
COMB TYPE
•••• ••••
STATISCALLY BRANCHED
•
•
••
•
• •
••
•
NETWORK
••
•
•
••
••
• •
•
•
•
• • ••
•
••
•
•
DENDRIMERS
STAR TYPE
• LINEAR
• CYCLOLINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
HOMOPOLYMER – Polymer synthesized from the same monomer (A)
COPOLYMER – When 2 monomers A and B (or more) are incorporated in the samemacromolecule
-A-A-A-A-A-A-A-A-
•••• COPOLYMERS
Considering there are n polymers, there will be n(n-1) copolymers
We can also vary the composition of monomers within the macromolecule
“Exponential” growth of materials available
TYPES OF COPOLYMERS
-A-A-B-A-B-B-A-B- RANDOM (OR STATISTIC) COPOLYMER
-A-A-A-A- B-B-B-B- BLOCK COPOLYMER OF THE AB (diblock) TYPE
-A-B-A-B-A-B-A-B- ALTERNATING COPOLYMER
-A-A-A-A-B-B-B-B-A-A-A-A--A-A-A-A-B-B-B-B-A-A-A-A-
-A-A-A-A-A-A-A-A-
-B-B
-B-B
- GRAFT COPOLYMER
BLOCK COPOLYMER OF THE ABA (triblock) TYPE
NOMENCLATURE OF COPOLYMERS
Ex: •••• Styrene-methyl methacrylate copolymer
Poly(styrene-alt-(methyl methacrylate))
Polystyrene-block-poly(methyl methacrylate)
Poly(styrene-ran-(methyl methacrylate))
ORPoly(styrene-a-(methyl methacrylate))
Poly(styrene-b-poly(methyl methacrylate))
Poly(styrene-r-(methyl methacrylate))
Polystyrene-graft-poly(methyl methacrylate)
-copoly(styrene/methyl methacrylate)
altblockgraftran
Poly(styrene-g-poly(methyl methacrylate))
OR
Ex: •••• Polybutadiene-block-(polystyrene-graft-polyacrylonitrile)
B = butadieneS = styreneA = acrylonitrile
-B-B-B-B-B-B-S-S-S-S-S-S-
-A-A
-A-A
-A-A
-
block-copoly(butadiene/graft-copoly(styrene/acrylonitrile))
Ex: •••• Poly(styrene-alt-acrylonitrile)- block-polybutadiene-block-(poly(methyl methacrylate)-graft-polystyrene)
B = butadieneS = styreneA = acrylonitrileM = methyl methacrylate
-S-A-S-A-S-A-S-A-B-B-B-B-B-B-B-B-B-M-M-M-M-M-
-S-S
-S-S
-S-S
-
• LINEAR
• CYCLOLINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
R R H R R H HH H R H H R R
•••• ISOMERISM IN POLYMERIC CHAINS - TACTICITY
CONFORMATIONS – Resulting from the rotation around a chain bond or side group
P H H
0 120 240 θθθθ
Epot
P
HR
H H
P
HR
H PP
HR
P H
θθθθ
CONFIGURATIONS – Resulting from the existence of pro-chiral atoms
ISOTACTIC
RRRRRRR r r r r r rSYNDIOTACTIC
n
RRRRRRR
n
m mr r r rATACTIC
= r (racemic) diad = syndiotactic diad
= m (meso) diad = isotactic diadm
r
• LINEAR
• CYCLOLINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
•••• MACROMOLECULAR NETWORKS
• Loose Networks
••••••••
•••• ••••
••••
••••
••••
••••
ELEMENTARY CHAIN
Portion of chain in between 2 branching points
••••••••
••••
ELEMENTARY CHAIN > 5 MONOMERIC UNITS
Exs: •••• VULCANIZED RUBBER
Sx
Sx~ x=3
~ 1 crosslink/ 300 RU
•••• crosslinked POLY-HEMA (Poly(hydroxyethyl methacrylate))
This polymers forms loose networks when crosslinked.The solvent penetrates the interstitial voids forming a gel (it swells)
• Dense Networks(Thermosets)
ELEMENTARY CHAIN < 5 MONOMERIC UNITS
The linear polymers are thermoplastics
THERMOSETS:
- ARE INSOLUBLE
- DO NOT SWELL WITH ANY SOLVENT
- ARE RIGID
- ARE INFLEXIBLE
- ARE BREAKABLE
The linear polymers are thermoplastics
Exs: •••• EPOXY RESINS
HO OH(n+1) CH CH2
O+ (n+2) CH2Cl
- (n+2) NaCl
NaOH
HCH2C
O
CH2 O O CH2 CH CH2
OH
O O CH CH2
O
CH2
n
bisphenolepichlorohydrin (excess)
“prepolymer” (DP n = ~3 – 10)
Pre-polymer reacts with epoxyfunctonal groups
∆∆∆∆
DENSE NETWORKS
- Strong glues (ARALDITE© type)
- “Fibreglass” for leisure boats, laminates, etc.
HO C OHCH3
CH3
bis-phenol A
•••• PHENOL-FORMALDEHYDE RESINS
Reaction with an excess of phenol
Prepolymer (n ~ 3 - 10) (Novolac)
In moulding, further formadehyde is added(or paraformaldehyde or hexamethylenetetramine)
OH
+ C O
H
H
OH OHOH
excess
pH ~ 4.5 - 6
SnR4 ou M(OR)n
- H2O
- Parts of electrical equipment- Electrical switches- Telephones (old ones)- Heaters, etc.- Furniture coatings
DENSE NETWORK
CH2 CH2
CH2
OH
CH2
CH2
OH
CH2
CH2
OH OH
CH2
CH2
CH2OH
H2C
H2C
Resite- Insoluble- Infusible
Reticulated polymer
∆∆∆∆(>230ºC)
CH2O
OH
CH2
OHOH
CH2
n
Novolac(linear prepolymer with n ~ 3-10)
C O
H
H
+ C
O
H2N NH2∆∆∆∆
C
O
H2N NH CH2 OH +
H
O
H
C
O
NH NH CH2 OHCH2HO
C
O
NH NCH2
CH2
N
CH2CH2N
CH2 NH CH2
C NH CH2O
∆∆∆∆ ∆∆∆∆
+ H2O
H
O
H
H
O
H
+ ++
urea
•••• UREA-FORMALDEHYDE RESINS
C NH CH2O
- Furniture coatings- Electrical equipment
∆∆∆∆
DENSE NETWORK
etc.
CH2N N CH2 NCH2N
C
CC
C
CH2 N
CO
O O
O O
CH2N N CH2 NCH2N
C C
CH2 N
OO
Reticulated polymer
C O
H
H
+∆∆∆∆N
N
N
H2N NH2
NH2
N
N
N
N NH
NH2C CH2
CH
HOH2C
CH2melamine
•••• MELAMINE-FORMALDEHYDE RESINS
- Furniture coatings (Formica©)
CH2CH2melamine
∆∆∆∆
DENSE NETWORK
etc.
• LINEAR
• CYCLOLINEAR
• BRANCHED
• COPOLYMERS
PRIMARY STRUCTURE
PRIMARY
resulting from the covalent bonds between repeating units
• COPOLYMERS
• POLYMER CHAIN ISOMERISM AND TACTICITY
• MACROMOLECULAR NETWORKS
• NATURAL MACROMOLECULES
PRIMARYSTRUCTURE
•••• NATURAL MACROMOLECULES
- POLYSACCHARIDES- PROTEINS AND POLYPEPTIDES- NUCLEIC ACIDS- NATURAL RUBBER
• Polysaccharides
DP=15000 (in cotton)
DP=10000 (in wood)
Native cellulose
DP=2600
Cellulose separation from lignin
(there is some degradation)
(DP=150-7000)
(DP>7000)
cellulose xanthate(water soluble)
• Cellulose (Modifications)
spinningfibres H+
Cellulose
fibresviscose rayon
slit
H+
Cellophane sheet
Textile fibres
Rayon acetate
spinning
Regenerated Cellulose
cellulose nitrate
Plastics, lacquers, explosives
cellulose hydroxyacetate
emulsifier, shampoo
additives (thickeners)
cellulose acetate Rayon acetate
10 - 11% N 13.5% N
aminoacid
• Polypeptides (Proteins)
They are polymers (or copolymers) of aminoacids
- H2O
PEPTIDE BOND
Peptides → 2 – 10 units
Polypeptides → > 10 units
Exs: - Wool, hair, etc. → αααα-keratin
- Silk → ββββ-keratin (fibroin)
• Nucleic Acids
Polyesters obtained from the condensation reaction between phosphoric acid and a sugar (D-ribose, D-2-deoxyribose)
DNARNA
O
H
HH
H
CH2
HO
PO
O
OH
base
Ex: DNA
SECONDARY STRUCTURE
resulting from the spatial arrangement of the main chain segments according to regular patterns, which are dictated by stereochemistry (most stable conformations) or hydrogen bonds (αααα-helix or ββββ-sheet)
Ex: Isotactic vinyl polymers tend to acquire a minimum energy conformation by curling up on itself,
adopting an αααα-helix conformation, that enables the minimization of the repulsion between side groups
R R R R R R R
n
Hydrogenbond
•••• αααα-Helix
Ex: Some proteins acquire αααα-helix- or ββββ-sheet structures owing to the establishment of intramolecular hydrogen bonds
Hydrogenbond
αααα-Helix(top view)
Hydrogenbond
bond
Hydrogenbond
•••• ββββ-Sheet(folded)
Protein foldsin ββββ-sheets
TERTIARY STRUCTURE
resulting from the whole tridimensional structure of the chain, which is conditioned by intramolecular forces and hydrogen bonds between distant segments of the chain
Intramolecular arragement RIBONUCLEASE
•••• Tertiary structures composed only by αααα-helices secondary structures
•••• Tertiary structures composed only by ββββ-sheets secondary structures
•••• Tertiary structures composed by αααα-helices and ββββ-sheets secondary structures
QUATERNARY STRUCTURE
resulting from the interaction between different chains
DNA(resulting from the association of 2
polynucleotide chains, through H-bonds between the bases)
HEMOGLOBINE(resulting from the association of 4 proteins: 2 αααα-globines and 2 ββββ-globines. Each globine has a hemecontaining a Fe atom)
AGREGGATES
• COLLOIDS
• MICELLES
•••• Colloids
Basically insoluble materials, which are kept in solution, as molecular aggregates(very tiny and invisible), owing to stabilizing factors, for example, electrostatic repulsion.
These factors prevent particle growth and precipitation
SOL – When the colloids move without kinematic restrictions
GEL – When the colloids touch each other forming semi-permanent bonds, restrictingtheir thermal motion (physic gel) → analogy with polymeric networks
COLLOIDSHydrophobic
Hydrophilic
•••• Micelles
Agreggates of small molecules, generally thermodynamically stable (opposite to colloids)
Observed in molecules containing a:
- Hydrophilic part (polar group)
- Hydrophobic part (nonpolar group)
Detergentsor
Surfactants
Increase of thesurfactant concentration
Increase of thesurfactant concentration
LAYERS(formation in bulk
solution)MICELLES(formation in bulk
solution)
INDUSTRIAL POLYMERSmost important
Gross annual consumption of polymers: 150 Mton/Year
- PE (LDPE + HDPE)- PP- PVC- PS- Styrene-Butadiene- Acrylonitrile-Butadiene-Styrene (ABS)- Polyamides (Nylon-6) - Polyesters (PET and PBT)
TH
ER
MO
PLA
ST
ICS
(85
%)
COMMODITY(90%)
- Polyamides (Nylon-6,6)- Polycarbonates- Polyesters- Poly(oxymethylene) (POM)
99%
- Phenol-formaldehyde- Urea-formaldehyde- Unsaturated Polyesters- Epoxy Resins- Melamine-Formaldehyde
90%
TH
ER
MO
SE
TS
(15
%)
PLASTICS(56%)
TH
ER
MO
PLA
ST
ICS
ENGINEERING- Poly(oxymethylene) (POM)- Poly(phenylene oxide) (PPO)- Poly(imides)- Polysulfones- etc.
- Polyester (PET, etc.)- Polyamides (Nylon 6 and 6,6, etc.) - Olefinic (PP, etc.)- Acrylic (AN 80-90% + VA or VC)
70%
- Cellulose acetate (rayon acetate)- Cellulose xanthate (viscose rayon)CELLULOSIC
NON-CELLULOSIC
FIBRES(18%)
SYNTHETIC
(18%)
NATURAL(50%)
- Cotton (polysaccharide)(~80%)- Wool (polypeptide) (20%)-Silk (polypeptide) (less important)
RUBBERS(11%)
SYNTHETIC(Elastomers)
- Styrene – butadiene (SBR)- Polybutadiene (“synthetic rubber”)- Ethylene-propylene-diene (EPDM rubber)- Polychloroprene (“neoprene rubber”)- Poly(isoprene) ( “natural synthetic rubber”)- Acrylonitrile-butadiene (“nitrile rubber”)- Isobutylene-isoprene (“butyl rubber”)- Polysiloxane (“silicone rubber”)- Polyurethane (“urethane rubber”)- ABA copolymers (“thermoplastic elastomers”)
70%
(11%)
NATURAL(Trees)
- Hevea Brasiliensis (obtained from the latex, which contains 32-35% ofpoly(isoprene) 97% 1,4-cis)
- Guayule (Parthenium argentatum) (obtained from the tree pulp,which is boiled and refined)
- Chicle (obtained from the latex, which contains 32-35% of a mixture oflow molecular weight poly(isoprene) 1,4-cisand 1,4-trans)
- Styrene-butadiene latex- Poly(vinyl acetate)- Poly(acrylate esters)
PAINTS
With very complicated formulations:including solvents, filling agents,
- Phenol-formaldehyde- Urea-formaldehyde- Epoxy Resins- Cyanoacrylates
ADHESIVES
including solvents, filling agents,stabilizers, pigments, etc.
Polymers
Fibres Termoplastics Thermosets Elastomers
CrystallineCrystalline Amorphous
Amorphous Amorphous
PROPERTIES AND STRUCTURE
Cristalitos
Matriznão cristalina
crystallites (crystalline zones)
Amorphous zones
Crystalline or Semicrystalline Polymers
When the percentage of crystallites is largely the majority with respect to amorphous zones.In other words, when there are:
Syndiotactic
- Strong intermolecular forces(hydrogen bonds and Keesom forces)
- Highly stereoregular structures(isotactic or syndiotactic polymers)
Isotactic Nylon 6,6- Hydrogen bonds
- permanently aligned dipoles
It is characterized by a melting temperature – Tm
Amorphous Polymer
When the morphology is mainly amorphous, lacking or having few crystallites.
It is characterized by a glass transition temperature–Tg
Tg - temperature at which long range (20 to 50 atoms) chain rotations and translations are observed, the polymer
acquiring elastomeric properties. Further increasing the temperature the polymer will lose these properties
and will melt to give a liquid.
There is:- an increase of specific volume- a change in the specific heat
Amorphous and semicrystalline polymeershave aTg and aTm
Amorphous and semicrystalline polymers:Elastomers: Tg < Tambient
Thermoplastics: Tg > Tambient
- a change in the specific heat - alteration of the refractive index and thermal conductivity
T T Tv f
Volu
me
espe
cífi
co
Sólido
não cristalino
Líquido
Cristal
g
TYPES OF AVERAGE MOLECULAR WEIGHTS OF POLYMERS
Molecular Weight ≡≡≡≡ Molecular Mass≡≡≡≡ Molar Mass(Units: g/mol)
It depends basically on the determination method used:
- Colligative methods(freezing-point depression, boiling point elevation,changes in vapour pressure, osmometry)
•••• NUMBER-AVERAGE MOLECULAR WEIGHT,
Resulting from measurements depending on the number(concentration) of macromolecules:
nM
i i ii 1 i 1
w w N M∞ ∞∞ ∞∞ ∞∞ ∞
= == == == == == == == =∑ ∑∑ ∑∑ ∑∑ ∑
w = total mass of polymer samplewi = mass of a chain with a degree of polymerization of iNi = number of moles of a chain with a molecular weight of M i
changes in vapour pressure, osmometry)
- End group analysis
i ii 1
n i ii 1
i ii 1 i 1
N Mw
M x M
N N
∞∞∞∞
∞∞∞∞====
∞ ∞∞ ∞∞ ∞∞ ∞====
= == == == =
= = == = == = == = =∑∑∑∑
∑∑∑∑∑ ∑∑ ∑∑ ∑∑ ∑
xi = molar fraction of a chain of the i type = i i
TOTALi
i 1
N NN
N∞∞∞∞
====
====
∑∑∑∑
i i ii 1 i 1
ni
iii 1 i 1
N M w
Mw
NM
∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =
= == == == =∑ ∑∑ ∑∑ ∑∑ ∑
∑ ∑∑ ∑∑ ∑∑ ∑
- Light Scattering
•••• WEIGHT-AVERAGE MOLECULAR WEIGHT,
Resulting from measuremnts depending on the massof macromolecules:
wM
- Equilibrium Sedimentation
2i i i i
i 1 i 1w i i
i 1i i i
i 1 i 1
w M N MM m M
w N M
∞ ∞∞ ∞∞ ∞∞ ∞
∞∞∞∞= == == == =
∞ ∞∞ ∞∞ ∞∞ ∞====
= == == == =
= = == = == = == = =∑ ∑∑ ∑∑ ∑∑ ∑
∑∑∑∑∑ ∑∑ ∑∑ ∑∑ ∑
mi = mass fraction of a chain of the i type = i i
TOTALi
i 1
w ww
w∞∞∞∞
====
====
∑∑∑∑
2i i i i
i 1 i 1w
i i ii 1 i 1
N M w M
M
N M w
∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =
= == == == =∑ ∑∑ ∑∑ ∑∑ ∑
∑ ∑∑ ∑∑ ∑∑ ∑
Resulting from measurements of ultracentrifugation sedimentation of polymer solutions
3 2i i i i
i 1 i 1z
2i i i i
i 1 i 1
N M w M
M
N M w M
∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =
= == == == =∑ ∑∑ ∑∑ ∑∑ ∑
∑ ∑∑ ∑∑ ∑∑ ∑
•••• Z-AVERAGE MOLECULAR WEIGHT, zM
a 1 ai i i i
i 1 i 1
a a 1i i i i
i 1 i 1
N M w M
M
N M w M
∞ ∞∞ ∞∞ ∞∞ ∞++++
= == == == =∞ ∞∞ ∞∞ ∞∞ ∞
−−−−
= == == == =
= == == == =∑ ∑∑ ∑∑ ∑∑ ∑
∑ ∑∑ ∑∑ ∑∑ ∑
•••• GENERAL EQUATION OF MOLECULAR WEIGHTS
n
w
z
M a 0
M a 1
M a 2
⇒⇒⇒⇒ ====
⇒⇒⇒⇒ ====
⇒⇒⇒⇒ ====
z w nM M M≥ ≥≥ ≥≥ ≥≥ ≥Thus:
z w nM M M= == == == =• When:
w
n
M1
M====
M i
Ni
ALL THE CHAINS HAVE THE SAME LENGTH
MONODISPERSE POLYMER
•••• POLYDISPERSITY INDEX (POLYDISPERSITY), w nM / M
z w nM M M> >> >> >> >• When:
w
n
M1
M>>>>
M i
Ni
THE CHAIN HAVE A MOLECULAR WEIGHT DISTRIBUTION
POLYDISPERSE POLYMER
M i
Ni
σσσσ
22
i i i iN M N MM
∞ ∞∞ ∞∞ ∞∞ ∞
∑ ∑∑ ∑∑ ∑∑ ∑
σσσσ – distribution standard deviation:
i i i iwi 1 i 1
nn
i ii 1 i 1
N M N MM
M 1M
N N
= == == == =∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =
σ = − = −σ = − = −σ = − = −σ = − = −
∑ ∑∑ ∑∑ ∑∑ ∑
∑ ∑∑ ∑∑ ∑∑ ∑
2nd moment ofthe distribution
1st moment of the distribution
The larger , the broader the distributionw
n
MM
Resulting from viscometry measurements in polymer solutions
1 1
1i i i i
i 1 i 1v
i i ii 1 i 1
a aa aN M w M
M
N M w
∞ ∞∞ ∞∞ ∞∞ ∞++++
= == == == =∞ ∞∞ ∞∞ ∞∞ ∞
= == == == =
= == == == =
∑ ∑∑ ∑∑ ∑∑ ∑
∑ ∑∑ ∑∑ ∑∑ ∑
•••• VISCOSITY-AVERAGE MOLECULAR WEIGHT, vM
[[[[ ]]]] avKMη =η =η =η =
[ηηηη] = intrinsic viscosityK = constanta = constant (normally, 0,8 > to > 0,5)
tabulated or measuredexperimentally
w v nM M M≥ ≥≥ ≥≥ ≥≥ ≥
normally closer to wM
Problem 2: After mixing 9 g of a polymer sample with a molecular weight of 30000 to 5 gof a polymer with a molecular weight of 50000, what are the Mn, Mw, Mz and Mw/M n of the resulting sample?
Problem 1: After mixing 9 mol of a polymer sample with a molecular weight of 30000 to 5 molof a polymer with a molecular weight of 50000, what are the Mn, Mw, Mz and Mw/M n of the resulting sample?
Problem 3: Calculate the Mn, Mw, Mw/M n and σσσσ for the following molecular weight distribution(the coordinates of 9 particular points of the distribution are shown):
70
10, 16000
25, 26000
50, 3600055, 46000
65, 56000
40, 66000
20, 7600015, 86000
5, 960000
10
20
30
40
50
60
70
0 50 100 150
M x 10 -3
Uni
dade
s ar
bitr
ária
sA
rbitr
ary
Uni
ts
- M. P. Stevens, "Polymer Chemistry - An Introduction", 3rd ed., Oxford Univ. Press, 1999 (DEQ library: 2 nd ed., 1990)
- P. Munk, T.M. Aminabhavi, "Introduction to Macromolecular Science", 3rd ed., John Wiley &Sons, N.Y., 2002. (DEQ library: 1 st ed., 1989)
Bibliography (Block 1)
- G. Odian, “Principles of Polymerization”, 4th ed., Wiley-Interscience, N.Y., 2004(Pedro T. Gomes office )
- M Michalovic, K. Anderson, L. Mathias, “The Macrogalleria”, site do Polymer Site LearningCenter (da University of Southern Mississippi) (http://www.pslc.ws/macrog.htm)
Recommended