Preparation, Grafting Mechanism And Crystal Properties Of Co-monomer/Maleic Anhydride Melt Grafting Isotactic Polybutene-1

Maleic Anhydride (MAH) melt grafting isotactic polybutene-1(iPB-1) wereobtained in a Haake mixer by using St, AMS or Decene as comonomers, DTBP asinitiator. The influence of initiator, monomer and co-monomer content on graftingdegree(Gd) and Melt Flow Rate(MFR) was investigated respectively. The resultsshowed that the increasing of initiator content would improve the Gd of MAH to someextent, but excessive initiator could cause severe degradation; as a comonomer, AMSand Decene could remarkably enhance the Gd of MAH and also could causecrosslinking reaction.The Shore D hardness measurement results showed the existence of(MAH-co-AMS) or (MAH-co-Decene) side chain could greatly accelerate the crystalformⅡto formⅠtransformation rate of iPB-1and the transformation rate increasedwith increasing Gd. Polarizing microscope results showed that after grafting MAHonto polybutene-1, crystallite dimension was smaller, the nucleation density of iPB-1increased and MAH could accelerate promote nucleation formation process of iPB-1during crystallization.Contact angle measurement results showed that MAH grafting onto iPB-1couldimprove the surface polarity of iPB-1, and the surface polarity increased with the Gdincreaseing.The reaction mechanism of comonomer/MAH melt grafting onto iPB-1werestudied. The results showed that, without comonomer, MAH was grafted on iPB-1 after degradation of macroradicals. After adding Decene, it reacted firstly with MAHto produce Decene-co-MAH; After adding St or AMS, they reacted firstly with MAHto produce electron transfer complex. These intermediates were grafted on main chainsbefore degradation of macroradicals. Three of monomers could effectively suppressthe degradation of macroradicals, increased Gd of MAH. With AMS and Decene ascomonomers, macroradicals tended to coupling termination, resulting in molecularweight and polydispersity increasing.