Research Of Preparation And Interface Properties Of Wheat Straw Fiber Reinforced Waste Polyethylene Composites

The resource utilization of straw and packaging waste plastics has aroused wide public concern, and developing the high value-added utilization technology which can transform waste into assets, is of great importance in environmental protection and resource conservation.In this research, wheat straw/recycled polyethylene composites (WRPCs) was manufactured with wheat straw fibers (WF),which come from the Guanzhong region, and recycled polyethylene (rPE) by extrusion processing and hot pressing technology. The influence of WF size and loading,interfacial modifiers kind and loading, enzyme, enzyme and compatilizer on the mechanical properties, thermal stability and moisture absorption of WRPCs was investigated. The chemistry components and the interface properties of WRPCs were analyzed by Fourier Transform Infrared Spectroscopy (FTIR) analyzer and Scanning Electron Microscopy (SEM). The main conclusions of this article were as follows:(1) Without adding any interfacial modifiers, the mechanical properties of WRPCs exhibited a gradual increasing trend with increasing WF loadings. However, the mechanical properties of WRPCs with WF began to decrease when the WF increase to 40wt%. Moreover, the WRPCs with 60 mesh WF have the best mechanical properties and thermal stability, compared with the WRPCs adding 100 or 200 mesh WF.(2) The FTIR spectra showed three type of compatilizers MAPE, MAPE Wax and KH550 could react with the hydroxyl groups of WF. The SEM indicated the three kinds of compatilizers could also improve the interfacial properties of WRPCs. Addition 40wt% WF and 2wt% MAPE Wax to the WRPCs reached the maximum value in tensile strength, flexural strength and flexural modulus, which were approximately 15.0 MPa、23.8 MPa and1646.4 MPa, respectively. However,the mechanical properties of WRPCs began to decrease when the MAPE Wax increases to 2 wt%.And the DSC curve showed the compatilizers treatment methods could promoted the crystallization process of WRPCs.(3) The enzyme and alkali treatment methods had significant influence on the modification of WF surface, and the xylanase and cellulose compound treatment method had the best effect on the modification of WF. Furthermore, the enzyme or alkali treatment methods could remarkably improve the thermal stability of WF, and promoted the crystallization process of WRPCs. The composites PFXC40 treated with enzyme and alkali had the best mechanical properties and water resistant.(4) The composites PFXC40W2, which treated with xylanase, cellulose and compatilizer were similar to the composites PFX40W2, which treated with xylanase and cellulose in tensile strength and flexural properties, but composites PFXC40W2 had the lowest water absorption.The SEM indicated the composites PFX40W2 and PFXC40W2 treated with enzyme and alkali compound treatment, existed good interfacial properties between fiber and substrate, and showed interfacial bond property.