EXTENDING PP'S FOAMABILITY THROUGH TAILORED MELT STRENGTH AND CRYSTALLISATION KINETICS

摘要

The foamability of four polypropylene (PP) resins have been studied with varying both chain architecture (long-chain branching) and chain regularity (homo- and copolymers) of the foaming behaviors of these PP materials with high and low melt strength, as well as fast and slow crystallization kinetics, were investigated using butane as a blowing agent. Experimental results showed that the foamability of PP can be varied by tailoring the melt strength and crystallization kinetics through chain architecture. These fundamental learnings suggest that the combination of slow crystallization kinetics, as achieved with PP copolymers, and high melt strength, as achieved with long-chain branched PP gives the broadest processing window.