马来酸酐改性聚丙烯的交联副反应

Study on crosslinking side reaction in maleic anhydride modification of polypropylene

用加入助剂和不加助剂的马来酸酐(MAH)熔融接枝改性聚丙烯(PP)。研究了单体MAH、引发剂过氧化二异丙苯(DCP)和助剂亚磷酸三苯酯(TPP)用量对PP交联的影响。PP交联副反应是由DCP引发生成的PP大分子自由基和由MAH激态分子生成的PP大分子自由基而产生的。TPP含有给电子体,可减小PP分子中甲基产生的正电诱导效应倾向,阻止PP发生分子内自由基的转移反应和分子间的转移反应,减小PP的交联;TPP化合物中含有磷原子,它与MAH的激态分子产生电子转移作用,使MAH的激态分子浓度减小,从而减少PP的交联。

Maleic anhydride （MAH） with and without additive was used to modify polypropylene （PP） via melt grafting reaction. The influence of dosage of MAH monomer, dicumyl peroxide （DCP） initiator and triphenyl phosphate （TPP） additive on crosslinking of PP was studied. The crosslinking side reaction of PP was caused by the macromolecular free radicals of PP originated from the initiation by DCP and from MAH molecules in excited state. The electron donor contained in TPP could weak the tendency of positive charge induction created by methyl on the PP macromolecule, prevent transfer reaction of free radical inside PP and transfer reaction between the macromolecules from happening and accordingly, could abate the cross-linking reaction of PP. The P atoms contained in the TPP compound and the MAH molecules in excited state could generate the electron transfer function, make concentration of MAH molecules in excited state diminish and sequentially, reduce the cross-linking reaction of PP.