Open Access

ARTICLE

Development of a Novel Extrusion Process for Preparing Rice Straw/LLDPE Composites

by Huicheng Xu, Hao Xie, Weidong Shan, Weihong Wang^*

Key Laboratory of Bio-Based Material Science and Technology (Ministry of Education), Material Science and Engineering College, Northeast Forestry University, Harbin, 150040, China

* Corresponding Author: Weihong Wang. Email:

(This article belongs to the Special Issue: Bio-based/Degradable Materials towards A Sustainable Future)

Journal of Renewable Materials 2023, 11(3), 1123-1135. https://doi.org/10.32604/jrm.2022.023959

Received 19 May 2022; Accepted 25 May 2022; Issue published 31 October 2022

Abstract

Straw utilization is a key issue related to agricultural production and air pollution control. In this study, a novel extrusion process was proposed to improve the physical and mechanical properties of the straw-reinforced linear low-density polyethylene (LLDPE) composite. Instead of crushing the straw and mixing it with plastic matrix, the new method mixes straw with plastic matrix in its original form. The intact long rice straws were parallelly spread on the LLDPE film and then rolled up together into a prefabricated roll. The rolls experienced three extrusion processes as follows: (1) twin-screw melting, cooling and crushing, single-screw extruding; (2) twin-screw melting and single-screw extruding; (3) directly single-screw extruding. The testing results showed that the straw/LLDPE composite (with a ratio of 6:4) prepared by Method (2) exhibited optimized properties. Characterization by scanning electron microscopy indicated that the damage to rice straw fibers was relatively minor, the orientation of long fibers was good, and the binding of fibers with the LLDPE matrix was excellent in this case. The results of dynamic mechanical testing (DMA), differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis demonstrated that composites prepared by the new process exhibited significantly improved thermal stability and energy storage modulus, compared with those prepared by conventional processes (e.g., extruded straw particles/LLDPE composite). The new proposed method yielded significantly enhanced mechanical properties while reducing dust pollution.

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