Physical and Mechanical Properties of Modified Wheat Straw-Filled Polyethylene Composites

Wentao Zhang, Jishuang Chen, Lemma Dadi Bekele, Yiliang Liu, Gregory Joseph Duns, Leilei Jin


This study investigates the effect of modified wheat straw on the physical and mechanical properties of modified wheat straw/high-density polyethylene (MWS/HDPE) straw-plastic composites. Wheat straw fibers with particle sizes in the range of 0.25 to 0.50 mm were modified with caprolactam (CPL). A Fourier transform infrared spectroscopy (FT-IR) analysis of MWS showed that when the CPL level was 5%, the intensity of the hydroxyl (O–H) and carbonyl (C–O) absorption peaks noticeably decreased, indicating a corresponding decrease in the polarity of the fibers. A physical analysis of the wheat straw fibers indicated that after the modification, the characteristics of the fibers were closer to those of the HDPE polymer matrix, thus contributing to good compatibility and dispersion of the straw fibers within the matrix. The composites of the high-density polyethylene with modified wheat straw particles were successfully synthesized using the melt blend method. The prepared composites were characterized using scanning electron microscopy (SEM), and their mechanical properties were investigated. The MWS/HDPE composites showed superior mechanical properties because of a greater compatibility of MWS with HDPE. The modified WS fibers function as “biological steel,” reinforcing the HDPE to produce bio-composites.


Wheat straw; Straw-plastic composites; Modification; Caprolactam; Mechanical properties

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022,; Lucian A. Lucia, (919) 515-7707, URLs:; ISSN: 1930-2126