Transcript OC 2/e 12 - University of Texas at Austin
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