Polymers

, I
polymers

↓ ↓ ↓
Natural Semi-Synthetic Synthetic
Polymers Polymers polymers
·
Cellulose Cellulose
·

acetate(rayon) -


polyethere
·
Starch ·
Cellulose nitrate nylon 6
·

, 6


·
Resins ·
Buna-S
·
Rubber



.
2 Addition Chain
or
growth paymerisation
:




·
monomers used are unsaturated compounds
.



Takes place either through formation of free radical
·




or ionic species




.
3 Free radical Mechanism :




·

wer radical generating initiator (catalyst) like benzoyl

Peroxide acetyl peroxide , tert-butyl peroxide
,
-




Chain initiation steps :



2615-ozing
O g



Gry-to-o-C-G45 -

Phenyl radical



City +
(Hz 22 = >
CoM5-CH2-CH2

Chain
propagating Step :




Sh5-C2-iH +
CHE Cr =
< GH5-C2-2-CH2-CH2

GHz) -CHztnC2- Cha