Dept of Chemical and Biomolecular EngineeringDept of Chemical and Biomolecular Engineering

CN4203R Polymer Engineeringy g g

Dr Tong Yen WahDr. Tong Yen WahOffice: E5-03-15Tel: 6516 8467Tel: 6516-8467

Email: chetyw@nus.edu.sg

Polymer Science vs EngineeringPolymer Science vs Engineering

Polymer Science Polymer EngineeringPolymer Science Polymer chemistry and

synthesis

Polymer Engineering Post-synthesis

processing of Polymer physics Structure and

mechanical properties

polymers Manufacturing of end-

productsmechanical properties Characterization

products Reaction engineering

Class ScheduleClass Schedule

Lectures : Tuesdays, 2 to 3 pmat E1-06-01at E1 06 01Wednesdays, 9 to 11 am at E5-03-20T t i l T d 3 t 4 Tutorials : Tuesdays, 3 to 4 pmat E1-06-01

Course OutlineCourse Outline

Week 1: IntroductionWeek 1: Introduction Basic concepts, definitions and nomenclature,

types of polymers molecular weighttypes of polymers, molecular weight Week 1 - 3: Synthesis

Step growth polymerization Step-growth polymerization Chain-growth polymerization, i.e. free-radical,

ionic and emulsion polymerizationionic and emulsion polymerization Copolymerization

Course OutlineCourse Outline

Week 4 - 6: PhysicsWeek 4 - 6: Physics Structure and configuration, i.e. crystalline

and amorphous melting and glass transitionand amorphous, melting and glass transition Thermodynamics and molecular weight Characterization by GPC mass spectrometry Characterization by GPC, mass spectrometry,

NMR, IR, light scattering, viscosity Mechanical behaviourMechanical behaviour

Course OutlineCourse Outline

Week 7 - 12: Polymer ProcessingWeek 7 - 12: Polymer Processing Week 13: Review

Course TextCourse Text

Principles of Polymer Processing (2nd Ed.), by Z.Principles of Polymer Processing (2 Ed.), by Z. Tadmor and C.G. Gogos, 2006

Polymers: The Elements of Polymer Science & y yEngineering (3rd Ed.), by A. Rudin and P. Choi, 2013

Supplementary readings: Introduction to Physical Polymer Science (4th Edition),

b L H S li 2006by L.H. Sperling, 2006 Introduction to Polymers (2nd Edition), by R.J. Young

and P A Lovell 1991and P.A. Lovell, 1991

Course AssessmentCourse Assessment

Final exam:Final exam: May 6, 2014 (AM) 2 hours, all varieties of question types2 hours, all varieties of question types 50%

Quiz: Feb or March, 2013Quiz: Feb or March, 2013 During lecture 30 minutes, short answer questions, q 10%

Group ProjectGroup Project

Group Design ProjectGroup Design Project

Group work groups of 2 students eachGroup work, groups of 2 students each Form group and select topic by Jan 28,

20142014 Presentation during last 6-7 weeks 40%

Course WebsiteCourse Website

On IVLE search for module CN4203ROn IVLE, search for module CN4203R Update your IVLE email, announcements

will be made through IVLEwill be made through IVLE Lecture notes and materials will be posted

IVLE kbion IVLE workbin IVLE forum is open to participation,

questions and debate

Journals for PolymersJournals for Polymers Macromolecules Advances in Polymer Science POLYMER

A P l i Acta Polymerica Journal of Polymer Science, Part A (polymer

chemistry) and Part B (polymer physics)chemistry) and Part B (polymer physics) Journal of Macromolecular Science Trends in Polymer Science Macromolecular Symposia Plastics Engineering

History of PolymersHistory of Polymers

Natural polymersNatural polymers 1820 natural rubber

1840 it ll l 1840 nitrocellulose 1870 celluloid 1910 first truly synthetic polymer :

Bakelite 1930 to current present polymers

Names and numbersNames and numbers

mer - part of a repeating sequencemer part of a repeating sequence Monomer molecule that combines with other

monomers, one basic repeating unit, p g Polymer a large molecule that is composed of

many monomers (molecular weight >5000?)y ( g ) Oligomer molecule with fewer monomers Macromolecule large moleculeac o o ecu e a ge o ecu e Repeat unit portion of polymer that is repeated

Names and numbersNames and numbers

How to name a polymer:How to name a polymer: Look for monomer or repeat unit Identify possible precursory p p Poly(precursor) eg. Polyethylene

C C

H H

P l (h th l di id )

C C

H Hn

Poly(hexamethylene adipamide)

N (CH2)6

H

N

H

C (CH2)4 C( 2)6 ( 2)4O O n

Names and numbersNames and numbers

Polymerization reaction of monomers toPolymerization reaction of monomers to link up forming long chains

Functionality number of bonding sites in Functionality number of bonding sites in a monomer available for polymerizationL t t f ti lit f ti l Latent functionality functional groups that are not reacted during initial

l i ti l i tipolymerization, eg. vulcanization, epoxy

StructureStructure

Linear polymer straight chainLinear polymer straight chain Branched polymer with side chains

bonded to main branch at branch pointsbonded to main branch at branch points Network polymer 3D structure with many

i t t d h i d finterconnected chains, degree of crosslinking

HomopolymersHomopolymers

Polymer from only one species of monomer,Polymer from only one species of monomer, eg. polystyrene

But also for polymer from one type of repeat p y yp punits, eg. poly(ethylene terephthalate)

Structure:

A A A A Ann

CopolymersCopolymers

Polymer from more than one species ofPolymer from more than one species of monomer

More commonly used for polymer of more than y p yone type of repeat unit, poly(A-co-B)

Statistical copolymer: distribution obeys p y ystatistics, poly(A-stat-B)

Random copolymer: distribution is random, poly(A-ran-B)

A A A B A A B B B A

CopolymersCopolymers

Alternating copolymer: repeat units alternate,Alternating copolymer: repeat units alternate, poly(A-alt-B)

A B A B A B A B A B

Block copolymer: repeat units are in long

A B A B A B A B A B

Block copolymer: repeat units are in long sequences, polyA-block-polyB

A A A A AA A A A A B B B B B

CopolymersCopolymers

Graft copolymer: branch chains have differentGraft copolymer: branch chains have different type of repeat units, polyA-graft-polyB

B B B B B B B B

A A A A A A A A A A

B B B B B B B B

Other types of copolymers

BBBBBB

Other types of copolymers

Thermoplastics/ThermosetsThermoplastics/Thermosets Thermoplastic

polymer which soften and flows when heated cooling and heating cycle can be repeated

Thermoset Rigid, normally are network polymers cooling and heating cycles very little

Elastomer cross-linked rubbery polymer can be deformed (stretched) and recover quickly

Fibre stretchable but breaks, only recovers partly

Plastic intermediate tensile modulus, breaks when stretched

Natural PolymersNatural Polymers

Poly(amino acids)Poly(amino acids) Poly(saccharides)

P l ( l tid ) Poly(nucleotides)

Molecular WeightMolecular Weight Molar mass or molecular weight

Molar mass of one repeat unit multiplied by degree of polymerization (DPn or xn)

M = xM M = xM0

Polymers have distribution of molar mass

An

Polymers have distribution of molar mass Number average molar mass, Mn

ii MxMNM Weight average molar mass, Mw

iiin MxNM

2 ii

ii

iw MwMN

MNM i

2

Molecular WeightMolecular Weight z-average molar massg

2

3

i

i

MNMN

Mi

iw

Polydispersity Index (PDI) wMMPDI

i

Breadth of molar mass distribution Typical polymer PDI = 1.5 2.0

M di l PDI 1 0

nM

Monodisperse polymer PDI = 1.0 Also number-average DP,

W i ht DPnn MMx / 0

Weight average DP,oww MMx /