Immiscible thermoplastic polymer blends with alternative layered encapsulation structure: Modeling and processing

Abstract

“Encapsulation” is a common phenomenon during polymer melting processing, which supplied great opportunities for fabricating high-performance polymer products. In this work, two immiscible polymers, high density polyethylene (HDPE) and polyketone (PK), were used for preparing polymer blends with viscous encapsulation structures. Moreover, the effects of interfacial tension, viscosity ratio, and shear rate on the phase morphology evolution of HDPE/PK blends were investigated by numerical simulation and high-pressure capillary extrusion (HCE). Meanwhile, the formation mechanisms of HDPE/PK alternating layered encapsulation structure were explored by tracking the trajectory of PK droplets via numerical simulation. The results show that an alternative layered encapsulation structure of HDPE/PK was formed under the shear rate from 50 to 1000 s−1 with the interfacial tension over 1.35 mN/m. Moreover, it was found that the revealed mechanism in HCE was also applicable to the injection molding process. Therefore, this unique “microstructure-intelligent prediction-control” strategy of polymer blends is suitable for the industrial processing of high-performance polymer blends for desired applications.