Reactive modification of linear PP by radical mediated grafting in the melt state is investigated as a means of increasing its melt strength, thus resulting in improved foam processing characteristics. A tri-functional coagent, triallyl trimesate (TAM) is used to introduce long chain branching to the linear PP homopolymer. Rheological characterization is conducted to relate the rheological properties to the modified PP chain architecture. The foaming behaviour of the linear and branched PPs is investigated using a batch foaming apparatus with N_2 as a blowing agent.
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