[dalmatiner]

Many people say that a polymer is a kind of macromolecule where always the same unit is repeated. Since there are copolymers that have different units within their structure I find that quite confusing.

If you go by the IUPAC definition a polymer consists of macromolecules and macromolecules refers to a molecule of high relative molecular mass, which itself comprises the multiple of units from molecules of low relative molecular mass. There is also a side note in the IUPAC definition that synthetic polymers can be regarded as having high relative molecular mass if the addition or removal of one or a few units has negligible effect on the molecular properties.

I tried to understand this by using an example but it hasn't really helped me out either. Now I specifically tried to figure out, if synthetic plastic, where I ask myself again if plastic now means polymer or something else, can be referred to as a macromolecule or/ and a polymer and what the difference are.

I thought I'd try to understand it thinking of Polyethylene:

I thought that the macromolecule in Polyethylene is ethylen because it's the basic structural unit, but it actually has a low relative molecular mass. Then I thought maybe that's the exception where taking away or adding a unit doesn't change that much but since it is only one unit itself I can quite understand how that should work.

I just wanted to know what a macromolecule and a polymer exactly means since also in the IUPAC definition they are two different things but I can't really work out what it means if you really look at substances like PE or PET and where the differences are.

[chenbeier]

No double posts please