Fabricating 3D printable BIIR/PP TPV via masterbatch and interfacial compatibilization

Abstract

Fused deposition modeling is a highly promising and efficient additive manufacturing technology to fabricate the conceptual prototypes and functional components having complex geometries. Excellent melt flowability and strong bonding between the adjacent deposited filament are two vital physical indexes to evaluate 3D printable materials. In this work, using polypropylene grafted with maleic anhydride (PP-g-MA) as the compatibilizer, brominated butyl-rubber (BIIR)/polypropylene (PP) thermoplastic vulcanizate (BIIR/PP-TPV) with outstanding rheological, mechanical performance and 3D printability was fabricated via masterbatch procedure. For comparison, BIIR/PP-TPV without the compatibilizer was prepared via precompound procedure and masterbatch procedure, respectively. 3D printing properties, rheological, mechanical properties, and phase morphology of three types of TPV were compared. In the masterbatch procedure, the even dispersion of curing agents and the prolonged scorching time contribute to the homogenous crosslinking of BIIR and efficient formation of BIIR particles with a small size. The PP-g-MA locating in the interface region of BIIR/PP improves the compatibility of them. The superior rheology and low viscosity of PP-g-MA compatibilized TPV prepared by masterbatch procedure (mTPV-MA) are attributed to the low viscosity of PP-g-MA and small BIIR particle size. The low viscosity and higher polarity of mTPV-MA effectively improve the bonding strength between the adjacent layers of the printed product. This study may shed some new light on the preparation of 3D printable TPV.