A highly effective reactive liquid crystal for the improved β‐nucleation of isotactic polypropylene

Abstract

We report here the synthesis and characterization of a reactive liquid crystal (RLC) as a novel polymeric nucleating agent for the promotion of the nucleation efficiency of isotactic polypropylene (iPP). The RLC was synthesized by an in‐situ photo‐polymerization and was then grafted onto the molecular chain of iPP by the reactive blending. The phase transition and crystalline morphologies of RLC‐iPP in the β‐nucleation were studied. It is found that the nucleation efficiency of β‐crystals of iPP can be increased to 42% with a very small amount of RLC grafting, which is much higher than the reported nucleation efficiency of polymeric nucleating agents up to now (23%). In addition, we found that the nucleation efficiency of β‐crystals is strongly related to the concentration of RLC for the reactive blending. The nucleation efficiency was decreased from 42% to about 17% with the increase of RLC concentration from 0.5% to 4%. We propose a possible nucleation mechanism for this interesting phenomenon. It is expected that this new β‐nucleation RLC will have potential industrial applications in the future. POLYM. ENG. SCI., 54:2112–2120, 2014. © 2013 Society of Plastics Engineers