Microstructural Investigation of Copolymers. A Key in Revealing Relations Between Polymerization Conditions and Polymer Properties

摘要

Semiquantitative models to predict the three dimensional molar mass chemical composition distribution (MMCCD) and quantitative models to predict diad and triad fractions of copolymers prepared by solution copolymerization till high conversion, were developed. For the evaluation of experimental MMCCD's, a crossfractionation method was elaborated. Crossfractionation, NMR data, and model calculations show that the observed MMCCD and triad fractions of solution products agree with predicted MMCCD's and triad fractions. High conversion products exhibit significantly different Tg's compared with low conversion products having approximately the same composition and molar mass due to differences in (predictable) product distributions. Products obtained by emulsion copolymerization exhibit a significantly anomalous intra and intermolecular structure. These anomalies also show up in the properties of the emulsion products.