Non-isothermal crystallization analysis of recycled high-density polyethylene/black shale composites

摘要

In this study, recycled high-density polyethylene (REHDPE)/black shale (B-shale) composites were prepared by a melt-blending method using a B-shale nucleating agent and polyolefin elastomer (POE) and acrylic impact modifier (ACR) as plasticizers. The melt index, microstructure, mechanical properties, and non-isothermal crystallization behavior of REHDPE were analyzed to determine the effects of the nucleating agent and plasticizer. Scanning electron microscopy and the melt index indicated that POE and ACR increased the melt flow rate of the composites and improved the interfacial properties of B-shale and REHDPE. The non-isothermal crystallization processes of the REHDPE and REHDPE composites were successfully described by Hoffmann-Lauritzen theory, demonstrating that B-shale, POE, and ACR can synergistically accelerate the crystallization process of REHDPE. The Friedman method revealed that B-shale, POE and ACR reduced the crystallization activation energy by heterogeneous nucleation and increasing the melt flow, respectively. The POE and ACR further enhanced the nucleation activity of B-shale and the nucleation activity is negatively correlated with the B-shale content according to the Dobreva and Gutzow's methods. The synergistic effect of nucleating agent and plasticizer improved the mechanical properties of REHDPE and solved the problem in relatively low mechanical properties of recycled plastics. And it will provide a new strategy for the practical production of REHDPE.

关键词