Journal of Applied Polymer Science, Vol.109, No.2, 820-824, 2008
Study on a novel N-functionalized multilithium initiator and its application for preparing star-shaped N-functionalized styrene-butadiene rubber
A novel N-functionalized multilithium (N-M-Li) initiator was synthesized from divinylbenzene (DVB) and lithiohexamethyleneimine (LHMI), and its microstructure and molecular weight distribution were characterized by H-1-NMR and GPC, respectively. Reaction kinetics of synthesis of N-M-Li was also studied and the apparent propagation rate constants of different monomers in this reaction were obtained. Star-shaped N-functionalized styrene-butadiene rubber (SBR) was prepared by anionic polymerization using N-M-Li as initiator, N,N,N',N'-tetramethylethylenediamine (TMEDA) as polar additive, and cyclohexane as solvent. The molecular weight distribution of the target product was measured by GPC and the result showed that it contained a certain amount of star-shaped polymers. Three types of SBR were initiated by N-M-Li, LHMI, and n-BuLi, respectively, and then were contrasted in terms of the loss factor (tan delta) by DMA, which demonstrated that N-M-Li initiator could provide rubbers with improved hysteresis characteristics. (C) 2008 Wiley Periodicals, Inc.
Keywords:anionic polymerization;initiators;functionalization of polymers;star polymers;high performance polymers