硅烷偶联剂对木粉/HDPE复合材料力学与吸水性能的影响

Coupling Effects of Silane on the Mechanical Properties and Water Absorption of Wood Flour/HDPE Composites

采用乙烯基三甲氧基硅烷(A-171)、乙烯基三乙氧基硅烷(A-151)、γ-氨丙基三乙氧基硅烷(DB-550)、γ-缩水甘油醚氧基丙基三甲氧基硅烷(DB-560)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(DB-570)和γ-巯丙基三乙氧基硅烷(DB-580)6种含有不同取代基的硅烷偶联剂对木粉(WF)进行表面处理,然后与高密度聚乙烯(HDPE)混合挤出制备处理木粉/HDPE复合材料。对复合材料的拉伸、弯曲和无缺口冲击强度及吸水率进行测试,采用扫描电子显微镜(SEM)观察其断面微观形态,并对硅烷处理前后的木粉进行红外光谱(FTIR)分析,从而筛选出较适宜的硅烷偶联剂。结果表明:经这6种偶联剂对木粉处理后,复合材料的力学性能、耐水性和界面相容性都有所改善,其中A-171的处理效果最好,处理后复合材料的弯曲、拉伸和无缺口冲击强度分别提高了31.59%,31.26%和49.29%,冷水和沸水吸水率分别降低了59.71%和48.29%。通过对复合材料SEM观察和FTIR分析可知:A-171成功与木粉发生缩聚反应,最有效地改善了复合材料的界面相容性。这应归因于乙烯基三甲氧基硅烷兼有适宜地与木粉发生缩聚接枝反应及可能与HDPE发生加聚接枝反应的综合优势,偶联作用强,使木/塑界面相容性显著改善。

This study investigated the treating effects of wood flour（WF） with six silane coupling agents of Vinyltrimethoxysilane（A-171）, Vinyltriethoxysilane（A-151）, γ-Aminopropyltriethoxysilane（DB-550）,γ-Glycidoxypropyltrimethoxysilane （DB-560）, γ-Methacryloxypropyltrimethoxysilane （DB-570） and γ-Mercaptopropyl triethoxysilane （DB-580） respectively on the physical and mechanical properties of resulting wood flour/high density polyethylene （HDPE） composites. The flexural, tensile and unnotched impact strength and the water absorption were determined. The interaction of wood and silanes was investigated by FTIR and the fractural surfaces of samples were analyzed using a scanning electronic microscope（SEM）. The results showed that treatments with the silane coupling agents used caused the increase in the mechanical properties of the WF/HDPE composites, suggesting that the interfacial bonding was improved accordingly. The better treating effect was observed for the resulting composites coupled with vinyltrimethoxysilane, which resulted in an increase in the flexural strength, tensile strength, unnotched impact strength by 31.59%,31.26%, 49.29%, and a reduction in cool and boiling water absorption by 59.71% and 48.29% respectively. Vinyltrimethoxysilane was grafted on WF and improved the interfacial compatibility of the composites from the analyzed of the SEM and FTIR. This is mainly attributed to the grafting of vinylsilane with both wood and HDPE matrix.