Synthesis of Long-Chain Branched Propylene Polymers via Macromonomer Incorporation

Abstract

Long-chain branched (LCB) poly(propylene)s (PP) are synthesized by the incorporation of pre-formed, vinyl-terminated macromonomers using metallocene catalysts. LCB-PP polymers made with isotactic PP macromonomers are characterized by means of multi-angle laser light scattering and extensional viscosimetry. The LCB polymers exhibit enhanced melt properties, such as strain hardening and shear thinning. These properties are critical in many polymer fabrication processes, such as thermoforming, blow molding and foaming.