In irreversible step-growth polymerization, the molecular-weight distribution (MWD) of the polymers produced can be controlled via the reaction path. In this paper, the effect of intermediate monomer feed on MWD in batch reactors or continuous plug flow reactors is investigated using a kinetic approach. It is found that the polydispersity index (Pw/PN) of the MWD can be made larger than 2 and that its magnitude can be controlled by the extent of reaction in the first stage (before additional monomers are fed), Pl, the final extent of reaction, pf, and the amount of monomer fed additionally, qS. For non-linear polymerization, the effect of intermediate monomer feed is more significant than that for linear polymers, and the extent of reaction at the gel point, Pc, can be lowered significantly.
Посилання на статтю:
Control of molecular-weight distribution in step-growth polymerization:the intermediate monomer feed method / Hidetaka Tobita* and Yasuhisa Ohtani // Polymer. – 1992. – Vol 33. – P. 801-811.