Graft copolymerisation studies: Part 1. Models related to polyolefins

Abstract

The chemistry of free radical graft copolymerisation, initiated with t- butoxy radicals, has been investigated using 3-methylpentane and 2,4- dimethylpentane as models for LLDPE and PP, respectively. The tertiary C-H reaction site of 3-methylpentane is twice as reactive as the secondary position. However, the site of grafting from the polymer is determined by the concentration of tertiary and secondary reaction sites and the relative reactivity at these positions and hence grafting occurs most frequently from the secondary C-H reaction sites. Abstraction from 2,4-dimethylpentane is solvent dependent and occurs most readily at the tertiary position. Therefore, grafting will be predominantly c..