First shell substitution effects on hyperbranched polymers formed from monomers A(2) and B-3 with end-capping molecules

作者：Cheng Kuo Chung^*; Chuang Tsu Hwang; Tsai Teh Hua; Guo Wenjeng; Su Wei Fang

来源：European Polymer Journal, 2009, 45(10): 2942-2950.

DOI：10.1016/j.eurpolymj.2009.06.008

• Hyperbranched polymer
• First shell substitution effect
• Degree of polymerization
• Degree of branching
• Critical conversion

Hyperbranched polymers obtained by the polymerization of monomers A(2) and B-3 in the presence of end-capping molecules AR with a first shell substitution effect, FSSE, on the monomer B-3 were investigated by a kinetic model. The profiles of the average degree of polymerization, degree of branching, and critical conversion under various compositions were calculated by a generating function method. It was found that, if groups B in excess of A, the curves of critical conversion A of 100%, at which a gelation occurs, based on the initial compositions with substitution effect differ from that with equal reactivity of the groups B. The weight-average degree of polymerization, (DP) over bar (w), and degree of branching, DB, increase with increasing of the reactivity ratio of B. On the other hand, when the initial groups B are lower than A, there is no apparent difference of the curves of critical conversion B of 100% between the polymerizations with and without FSSE. At high conversion of B, 99%, for example, the (DP) over bar (w) and DB decrease with increasing of the end-capping molecules AR, but the (DP) over bar (w) and DB are less influenced by the FSSE.

• 出版日期2009-10