Synthesis Of Cardanol Glycidyl Ether Copolymers And Their Impact On The Structure And Properties Of Wood-Plastic Composites

Wood plastic composites (WPCs) is cheap, easily molding and anticorrosion compared to normal wood, and is widely used in field of furniture and plates. However, WPCs with high filler loading has some problems about processing, molding and selecting compatibilizer.Maleic anhydride/cardanol glycidyl ether copolymers (MGPPE) was synthesized from glycidyl3-pentadecenyl phenyl ether (GPPE) and maleic anhydride (MAH) initiated by BPO. And then the MGPPE was applied as a reactive comparabilizer to prepare HDPE/WF composite. Meanwhile, composites with GPPE and common comparabilizer such as MAH-g-PE (MPE) and mealted petroleum resin (C5) were also prepared for comparison purpose.The conversion rate of MAH in MGPPE was indirectly determined by1H NMR. An orthogonal experiment was used to investigate the impact of each factor on the MAH reaction conversion rate. And the optimum reaction processing for the highest conversion rate of MAH and the sequence of every influence factor were obtained. Meanwhile, Fourier infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and1H NMR results suggest that graft copolymerization had taken place successfully. The inferring reaction mechanism and the structure of MGPPE were proposed. Thermal gravimetric analysis (TGA) domesticated that graft copolymerization of GPPE and MAH was favor for improving thermal stability.The mechanical properties of WPCs with different MGPPE loading was studied by FTIR, contact angle measurement and interface morphological analysis. Furthermore, the interfacial property of WPCs and the modified mechanism of MGPPE were investigated. Composites with GPPE and common compatibilizer were also prepared for evaluating the compatibility of MGPPE. The results showed that the mechanical property and interface compatibility of composite improved with the addition of MGPPE, which modified effect is equal to MPE and higher than MCs. When the loading of MGPPE was4wt%, the compatibility was optimum for WPCs which showed the best mechanical property.The viscoelastic property and processing performance were studied by plate rheomter and Huck rheomter. A small amplitude oscillation experiment was applied to determine the impact of different WF loading and different compatibilizer on rheological properties of interfacial adhesion of WPCs. Furthermore, carreau model was applied to investigate the effect of WF loading and compatibilizer types on Newtonian index and relaxation properties. The results showed that the relaxation time could reflect the relationship between multi-scale structure and structure of WPCs. MGPPE was compatible with HDPE. Composite filled with MGPPE showed similar rules of modulus varying with strain and frequency, as composite without MGPPE. The presence of MGPPE prolonged the stress relaxation time, which lead to increased long carrying capacity of composite samples.In addition, property of isothermal crystallization for HDPE in high filled WPCs was further studied by combining DSC and XRD. And the impact of WF loading, compatibilizer types and the network structure of wood flour particles on crystallization kinetics parameters and thermodynamic parameters of HDPE matrix were analyzed. The major factors affecting crystallization behavior and crystallization process of HDPE matrix were summarized. The results suggested that WF and compatibilizer had little effect on the crystallization behavior of HDPE, but influenced the grain size of HDPE during crystallization process. Composite with compatibilizer exhibited a higher Avrami index than the one without, which meant that compatibilizer could promote the perfection of crystal growth.Finally, the impact of WF loading, temperature and compatibilizer types on hygroscopic property of composite was studied. In terms of water transport dynamics, variation for water absorption, moisture diffusion rate and the diffusion coefficient of WPCs was discussed. Meanwhile the characteristics of diffusion activation energy of WPCs were investigated from the thermodynamic aspects of water transport. Furthermore by means of the examination of the swelling rate of the composite, a pr model was proposed, which depicted the association of the water absorption and dimensional stability of the composite, to investigate the chemical modification effect quantitatively. The results depicted that moisture diffusion rate, balance water absorption and diffusion coefficients of the composite with MGPPE lower than the composite without MGPPE in the same WF loading and temperature condition. It is concluded that MGPPE was helpful for reducing the moisture expansion of the sample and improved the dimensional stability of the composite. And the effect was significant when the MGPPE content was higher.