[Mmx]

Hi Im New. Im having my exam next week topic on polymer. Can anyone explain the basic thing about polymer because i dont really get how it the polymer structure is drawn. Mine is not in english but in malay so its hard for me to understand. Sorry And Thx.

[Alberto_Kravina]

Hi Im New. Im having my exam next week topic on polymer. Can anyone explain the basic thing about polymer because i dont really get how it the polymer structure is drawn. Mine is not in english but in malay so its hard for me to understand. Sorry And Thx.

Well, Well, Well, first of all, "polymer" is a bit superficial. If you want to draw the structure of a specific polymer you have to say the exact name of the polymer.
I presume that your exam is about polymers in general.
If yes, the first thing that you have to know about polymers is that a polymer is a long chain of atoms, mostly C,H,O, sometimes N,   S in some elastomers...and so on.

There are three methods fo synthesize a polymer:

1.)Polymerisation: Many small molecules are put together (mosly under high pressure and/or temperature) and form a log chain. e.g. polyeth(yl)ene

n C₂H₄ -----pressure/catalysts/temperature-------> -[-CH₂-CH₂-]-

2.)Polyaddition: 2 or more substances are mixed togther and form a polymer

n(A + B + C + D ) ------->(A-B-C-D)_n

3.)Polycondensation: 2 or more substances are mixed together and they form a polymer, but the difference between Polyaddition and Polycondensation is that Polycondensation has water as a byproduct.

n(A-OH + H-B + A-OH + H-B)-----------> (A-B-A-B)_n + n H₂O

Note: A, B, C, D and so on can be various substances (gases, liquids and so on)
n is a number, it can be various from polymer to polymer.

Another very important thing is that there are 3 "kinds" of polymers:

-Thermoplastes
-Duroplastes
-Elastomers

Thermoplastes can be liquified when heated and can be given a certain form just by melting them and cooling down the melted polymer. (Thermos (greek) = heat). e.g. PE, PP, PS....

Duromers are very hard and can not be melted. Usually they're made with polyaddition. Durus (greek) = hard

Elastomers are elastic polymers. Usually the elastic properties are because of disulfide bondings between the chains. The guy that discovered this was called Goodyear (car tires)

[Borek]

Polycondensation has water as a byproduct.

I would rather put it as 'has some byproduct'. Usually with low molecular mass. Water - very often, but it can be for example HCl.

[Alberto_Kravina]

Oh I see...could it be NH₃ as well? Do you know any synthesis of a polymer where HCl (or some other stuff besides H₂O) is the byproduct?

[Borek]

Polyesters made from alkohols and acid chlorides:

Cl-C(=O)-R₁-C(=O)-Cl + H-O-R₂-O-H -> -[C(=O)-R₁-C(=O)-O-R₂-O]- + HCl

Note my unorthodox use of SMILES