Chemical Heterogeneity of Copolymers

Abstract

Chemical heterogeneity is a consequence of chemical composition distribution (CCD) which can be presented as, e.g. an integral or differential distribution curve. Information on the complex MW/CCD can be provided as shown in Fig. 2.1a and b by plotting w vs M. In Fig. 2.1a is, for a bipolymer, the average molecular weight due to all B units in a macromolecule, M _B, plotted vs the corresponding average M _A of all A units. This mode of plotting [1] is especially suited for the characterization of block copolymers, whereas Fig. 2.1b is more advantageous with statistical copolymers. In both forms of diagrams, the distribution surface can be indicated by contour lines projected onto the M _B vs M _A or x vs M plane.