Macromolecular Chemistry

Paul J Flory 1910-1985 Wallace H. Carothers 1896-1937

Chemistry 367L/392N

Nomenclature Methods

 Source name (more common use) – based on monomer name (polystyrene)  IUPAC, constitutional repeating unit – used in both source and structure names…messy!

 Abbreviations and acronyms – PMMA [poly(methyl methacrylate)]…also common  Trade names – marketing and technological literature

Chemistry 367L/392N

O CH CH O C CH 2 CH 3 O CH CH 2 CH 2 CH C N CH 2

Examples

1. Poly(1-acetoxyethylene) -

structure

2. Poly(vinyl acetate) -

source

1. Poly(but-1-ene-1,4-diyl) 2. Polybutadiene

a

1. Poly(1-cyanoethylene) 2. Polyacrylonitrile O CH 2 O 1. Poly(methylene) 2. Polyethene; polyethylene CH 2 1. Poly[(2,5-dioxotetrahydrofuran 3,4-diyl)(1-phenylethylene)] 2. Poly(maleic anhydride-

alt

-styrene) Ph

Chemistry 367L/392N

Industrial Influence: Trade Names

          PVC poly (vinylidene chloride) Saran wrap PVC poly (vinyl chloride) Pipe and records PET poly (ethylene teraphthalate) Coke bottles, Dacron Polystyrene Cups and packaging Delrin Bushings and engineering parts Lexan Bullet proof glass Teflon Non stick pans PVDF speakers and microphones Kevlar bullet proof vests Nylon Rope and fiber

Chemistry 367L/392N

Common Abbreviations

ABS LLDPE PA66 PC PET Selected examples (acrylonitrile butadiene styrene) (linear low density polyethylene) [polyamide (Nylon) 66] (polycarbonate) [poly(ethylene terephthalate)] PMMA PS PVC TP [poly(methyl methacrylate)] (polystyrene) [poly(vinyl chloride)] (thermoplastic elastomer polyolefin) PVF2 [poly(vinlylidine fluoride)] (www.plasticsusa.com/tradename.html)

Chemistry 367L/392N

Class Names

 Polyolefin  Polyester  Polyamide  Polycarbonate  Polyurethane Naming “classes” of polymers

Chemistry 367L/392N

Name ‘em or draw ‘em

Cl Br Cl Br Cl Br CH 2 -O -CH-CCl-CH 2 -O-CH-CHCl-CH 2 -O-CH-CHCl CH 3 CH 3 CH 3 Poly(ethylene-alt-carbon monoxide) Poly(1-oxopropanediyl) Poly(vinyl alcohol) Poly(1-methyl-1-phenylethylene)

Chemistry 367L/392N

Wallace Hume Carothers 1896-1937 Carothers, W.H., J. Am. Chem. Soc . 1929,

51

, 2548-58

Chemistry 367L/392N

Carothers Paper

Chemistry 367L/392N

Addition polymer

 Polystyrene H C H C H H ( C H H C H C H H C ) n

Chemistry 367L/392N

Addition Polymer

 Polyvinylchloride H H C C Cl H chloroethene H C H H C H C Cl H H C Cl poly(chloroethene) aka polyvinylchloride (pvc)

Chemistry 367L/392N



Condensation Polymer

Dacron

n

HO O C O C OH +

n

HO CH 2 CH 2 OH heat with an acid catalyst H 2 O + O C O C O CH 2 CH 2 O

n

poly(ethan-1,2-diyl benzene-1,4-dicarboxylate)

Chemistry 367L/392N

Condensation Polymer

Nylon 6,6 H N H (CH 2 ) 6 1,6-diaminohexane N H H O HO O C (CH 2 ) 4 C OH hexanedioic acid H 2 O + ( N H O (CH 2 ) 6 N C (CH 2 ) 4 H part of a nylon polymer chain O C ) n

Chemistry 367L/392N

Chemistry 367L/392N

HO 2 C CO 2 H + HO

A d d it io n

OH - H 2 O O O HO

(

O

Condensation

O

(

H N C O + N C O HO OH OCN H N O O O

Condensation?

O N H Ar O O O O

Addition?

O O

Condensation?

Chemistry 367L/392N

Another Problem

O O R C O R

Polyester from lactone

O C OH R CO 2 H O R O C + H 2 O

from ω-hydroxycarboxylic acid

Chemistry 367L/392N

Paul J Flory

1910-1985

The Nobel Prize in Chemistry 1974

"for his fundamental achievements, both theoretical and experimental, in the physical chemistry of the macromolecules"

Chemistry 367L/392N

Flory Clears Things Up

Polymer Structure is distinct from Polymerization Process.

O Addition Polymerization O HO O O Condensation Polymer H Condensation Polymerization HO O O H

Process Structure Addition Condensation

 Similar connections  Ring-opening  No by-products  New functional groups  Same composition (monomer = polymer)  Release of small molecules  Degradation gives different composition

Chemistry 367L/392N

Basic Types of Polymerization Mechanisms

Step-growth

HO O C CH 2 CH 2 OH Dimer Tetramer Octamer Hexamer ...

H O O C CH 2 CH 2 O H H 2 O

Chain-growth Ring-opening

RO -

+

O O O O O RO O H

Chemistry 367L/392N

Chain growth system

The characteristic of a chain polymer is that

polymer growth takes place by monomer reacting only with the reactive centers

.

Monomer does not react with monomer and the different-sized species such as dimer, trimer, and n-mer do not react with each other. The polymerization ceases when the active center is destroyed by termination reaction(s).

Chemistry 367L/392N

Step Growth system

A condensation takes place between two polyfunctional molecules to produce one larger polyfunctional molecule with the possible elimination of a small molecule such as water. The reaction continues until one of the reagents is used up.

Chemistry 367L/392N

The chain growth vs. step growth

Step Chain

Chemistry 367L/392N