A New Polymer Processing Technology for Polymer Blends with Unmatched Viscosity: Solid-State Shear Pulverization (S3P)

Abstract

Abstract Solid-State Shear Pulverization (S3P) is a new polymer processing technology capable of efficient mixing blends with different component viscosities (which are unprocessable by conventional melt extrusion due to the phase separation). S3P sub ects polymers to compression and shear, resulting in fracture into a powder of various particle size and particle size distribution. S3P also allows modification of properties by compatibilization of ordinarily incompatible polymers without adding premade copolymers or conventional functional groups. Additionally, because S3P produces powder, it is suitable for a solid-state dispersion of pigments, curing agents, catalysts and other additives without melting (unlike conventional compounding). After reviewing the S3P concept, this paper discusses recent experimental data. The research focuses on mixing like polymers such as virgin polypropylene (PP) with unmatched viscosity, resulting in blends with improved processability and a significant increase in elongation at break. A comparison with a conventional melt mixing by twin-screw extrusion is provided to demonstrate uniqueness of S3P processing. An additional example involves the mixing of dissimilar, ordinarily incompatible polymers such as recycled high-density polyethylene (PE-HD), low-density polyethylene (PE-LD), PP, polystyrene (PS), and polyvinyl chloride (PVC) with very different viscosities. Once again, the S3P-made material exhibited exceptionally high elongation at break as compared with that of the conventionally melt-mixed blend.