POLYMERS- NOTES

<<strong>A polymer is a large molecules composed of repeating structural units (monomers) connected by covalent chemical bonds



It’s the breaking down of double bond carbon atoms , and the the electrons in it are used to join to neighboring molecules .

In its case polymerization take place ,where lots of little molecules(monomers) join up to make one big molecule (polymer)



In the case of ethene lots of ethene molecules join together to make poly(ethene)


When propene polymerized you get polypropene



Polymerising chloroethene gives you poly(chloroethene).

2- condensation polymer

Here the polimerisation method is totally different . if one monomer contains an – OH group and the other an –H , then they add by forming a molecule of water . when they polymerise , the water molecule is split out between them .
Also the same way in splitting out of HCL molecule.


*by removing water

HOOC- ___ ___ COOH + H2N- ___ ___ NH2 --
(carboxylic acid) (amino group)

HOOC ___ ___ CONH ___ ___NH2 +H2O
( amide linkage )


{another way }


COOH ___ ___COOH + NH2 ___ ___NH2---
(dicarboxylic acid) (diamine) -H2O

(___ ___CONH___ ___ )n


(amide linkage)

*by removing HCL

COCL ___ ___ COCL +NH2 ___ ___ NH2 -----
-HCL

(____ ____CONH ____ ____)n
(amide linkage)



*by removing water


HOOC ___ ___ COOH +HO- ___ ___OH ----
(carboxylic acid ) (alcohol)

HOOC- ___ ___ COO___ ___OH
( ester linkage )

{another way}
OH___ ___OH + COOH ___ ___COOH à
(diol) (dicarboxylic acid) -H2O

(___ ___COO___ ___)n
(ester linkage)

……………………………………………………………………….


*by removing HCL

COCL ___ ___COCL + OH___ ___OH ---
(acid chloride) (diol) -H2O

(___ ___COO___ ___)n
(dicarboxylic acid)


USES


polyethene

Bags, plastic milk bottles
Not very strong , flexible

poly propene

To make ropes and crates
strong

polyvinaly chloride

Drainpipes, replacement windows
Quite strong and rigid

nylon

Make toothbrush and ropes
strong
To make clothing
Very strong