Please answer the following polymer chemistry question, show all steps, explain
ID: 574544 • Letter: P
Question
Please answer the following polymer chemistry question, show all steps, explain clearly! Thank you.
Most polymer bulk properties correlate in some fashion with average molecular weight and molecular weight distribution. in each case the bulk property relationship. absolute and one secondary - noting for each the underlying principle and the relative a) Show the various ways by which these two parameters are statistically expressed, noting b) Describe Two (at least) different techniques for measuring molecular weight - one advantages/disadvantagesExplanation / Answer
*Molecular weight distribution -
A typical synthetic polymer sample contains chains with wide distribution of chain length. This distribution is seldom symmetric and contains some molecules of high molecular weight. The exact breadth of molecular weight distribution depends upon the specific conditions of polymerization. Many properties like melt viscosity are dependent on molecular weight and molecular weight distribution. Therefore it is useful to define molecular weight averages associated with a given molecular weight distribution.
*Molecular weight averages-
The molecular weight distribution of commercial polymers is normally a continuous function. Therefore the molecular weight averages can be determined by integration of the mathematical form of molecular weight distribution. Such mathematical form includes theoretical distribution functions derived on the basis of statistical consideration of an ideal polymer.
Two techniques of measuring molecular weight
1) Gel permeation chromatography...
It is also known as size exclusion chromatography including high temperature to analyse organic soluble polymers with molecular weight ranging from 100 - 10000000
2) Mass spectrometry.