Question

What kind of polymer is polyvinyl alcohol? How do you know?

I don't really understand how to tell what kind of polymer this would be, and I also don't understand how I would explain why i know this. I've tried to answer this but I do not think it is a synthetic polymer like i think it is.

Answer 1

Polyvinyl alcohol is an addition polymer.

Explanation:

There are many different ways of classifying polymers.

One way is to classify them as synthetic or natural

Polyvinyl is indeed a synthetic polymer, but I think this question is asking for something else

Synthetic polymers can be further classified as addition or condensation polymers.

Polyvinyl alcohol is made from the addition polymer polyvinyl acetate.

An addition polymer is a polymer that is formed by molecules adding together without the loss of any atoms.

Each double bond "opens out" to form single bonds with neighbouring molecules:

`n underbrace("CH"_2"=CH"("OCOCH"_3))_color(red)("vinyl acetate") → underbrace("-"["CH"_2"-CH"("OCOCH"_3)]_n"-")_color(red)("polyvinyl acetate")`

`n` is a large number, usually running in the thousands.

The polyvinyl acetate is then converted to polyvinyl alcohol by reaction with methanol.

`underbrace("-"["CH"_2"-CH"("OCOCH"_3)]_n"-")_color(red)("polyvinyl acetate") + n"CH"_3"OH" → underbrace("-"["CH"_2"-CH(OH)"]_n"-")_color(red)("polyvinyl alcohol") + underbrace("CH"_3"COOCH"_3)_color(red)("methyl acetate")`