The experiment and simulation of enhanced mechanical performance for polyethylene terephthalate/high‐density polyethylene composites via domain size control

Abstract

AbstractSolid‐state shear milling (S3M) equipment is proficient for achieving room‐temperature ultrafine grinding of multicomponent polymers, demonstrating significant potential in polymer blending and waste plastic recycling. However, a systematic investigation of S3M's ability to control the domain size of multicomponent polymer is currently lacking, which was of great potential for the high‐value recycling of waste plastics that are difficult to separate and thermodynamically incompatible. As the raw material of beverage bottle, polyethylene terephthalate/high‐density polyethylene (PET/HDPE) system with tremendous production was hard to be recycled together. Therefore, in this study, we chose PET/HDPE for the study of domain size control efficiency of S3M on mechanical properties of polymer blend. We also measured the processing parameters during the fabrication of PET/HDPE blended powder to determine the optimal manufacturing parameters for the polymer composite with outstanding mechanical property. After 30 milling cycles, the powder size of PET/HDPE gradually decreased from 849.8 μm (2 cycles) to 43.2 μm, which related to PET domain size of 71.9 and 5.2 μm, respectively. Meanwhile, at 24 milling cycles, the PET/HDPE composites reached the highest tensile strength of 27.6 MPa, meeting the most proper milling condition for PET/HDPE system. Finite element computer simulation was introduced to further investigate the domain size influence on mechanical property of PET/HDPE composites, which acquired similar results with the experimental value before excessive milling cycles. Based on both the experimental results and simulation support, a theoretical basis for the domain‐size‐control analysis of S3M in multicomponent waste polymer recycling was established.