Molecular Parameters Of Star-branched Polymers Made By AB+A_f Type Polycondensation

This dissertation for M.S. degree is mainly concerning some theoretical investigations for the star-branched polymer formed by AB + Af typepolycondensation.Firstly, the statistical method was used to give the number of bonds formed for the star-branched polymer chains made by the AB + Af polymerization. Withthe help of the kinetic model described by the Smoluchowski-like coagulation equation, the mean square radii of gyration were given analytically.Furthermore, the z- and the weight average mean square radii of gyration were investigated explicitly. The results were much different from that of the hyperbranched polymers made by the ABf type monomers, where the former hadthe finite values when the reaction was quantitatively completed, and the latter reached the infinite values. In principle, by varying the number of the Af typemultifunctional core moieties, the average sizes, as well as the average degrees, can be controlled effectively. With the detailed discussions of polymerization process, the conversion dependence of the mean size of star-branched polymers are undertaken, and hence some of results given by this dissertation are able to provide a new way of investigating highlybranched polymer in a deep level.