Influence of a novel β-nucleating agent on the structure, mechanical properties, and crystallization behavior of isotactic polypropylene

Abstract

A novel β-nucleating agent of isotactic polypropylene (iPP), the potassium salt of 1,4,5,6,7,7-hexachlorobicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid (CA-19), was found and its effects on the mechanical properties, content of β-crystal, and crystallization behavior of iPP were investigated. The results showed the content of β-crystals of nucleated iPP ( kβ value) can reach 46.3% with 0.25 wt% CA-19. The impact strength and crystallization peak temperature of nucleated iPP greatly increased. Compared with pure iPP, the impact strength of nucleated iPP shows two times increase, and the crystallization peak temperature ( Tp) of nucleated iPP increased by 7°C. The spherulite size of the nucleated iPP dramatically decreased compared with that of pure iPP. The Caze et al. method was used to investigate the nonisothermal crystallization kinetics of nucleated iPP and the crystallization activation energy was obtained by the Kissinger method.