Branched polymers. I—Molecular weight distributions

Expressions are derived for the number and weight average molecular weights of branched molecules of a particular structural class as functions of the molecular weight averages of their constituent linear components. The branched structures treated are termed ‘comb molecules’ and consist of linear backbone chains to which linear side chains are attached by one end at various positions along the backbone. Proper choice of the parameters specifying the structure of the comb molecules reduces them, and the molecular weight relationships presented applicable to them, to the corresponding details characteristic of star shaped branched molecules. The relative effects of the number of side chains attached, the backbone and the side chain heterogeneities on the weight-to-number average ratios of the branched molecule systems are discussed.