热压温度对硅烷化木单板/聚乙烯薄膜复合材料性能的影响

Properties of silane modified poplar veneer/high density polyethylene film composites with varying pressing temperatures

为了研究热压温度对硅烷化杨木（107杨Populus×euramericana）单板/高密度聚乙烯（HDPE）薄膜复合材料各项性能的影响,以乙烯基三甲氧基硅烷（A-171）和过氧化二异丙苯（DCP）为杨木单板的改性剂,在不同的热压温度下（140,150,160,170℃）与HDPE薄膜复合制备了硅烷化杨木单板/高密度聚乙烯（HDPE）薄膜复合材料。采用万能力学试验机、动态力学分析仪（DMA）和冷场发射扫描电子显微镜（SEM）测定了不同热压温度下复合材料的物理力学性能、动态热力学性能以及胶接界面结构的变化。结果表明：热压温度为140~150℃时,复合材料的界面结合力较弱,胶接界面层存在明显的缝隙。当热压温度达到160℃时,硅烷化杨木单板与HDPE大分子自由基发生充分有效的胶合,形成能有效提高复合材料性能的胶接界面结构。当热压温度从140℃升高到160℃时,胶合强度、静曲强度（MOR）和弹性模量（MOE）分别由1.27 MPa,63.90 MPa和5 970.00 MPa增加到1.89 MPa,72.20 MPa和6 710.00 MPa,但热压温度继续增加,胶合强度和抗弯性能均降低。当热压温度从140℃增加到170℃时,复合材料24 h吸水率（WA）和吸水厚度膨胀率（TS）分别从72.41%和4.98%降至54.22%和4.09%。复合材料的储能模量保留率E′（130℃）由62.31%提高到92.01%,到达tanδmax的温度点从144℃延后至200℃。复合材料的耐高温破坏能力随着热压温度增加逐渐增强。

To study the influence of hot-pressing temperatures on the performance of silane modified poplar veneer / high-density polyethylene （HDPE） film composites, silane modified poplar veneer / HDPE film compos- ites were prepared using silane A-171 （vinyl trimethoxysilane） and dicumyl peroxide （DCP） as veneer modifiers with hot-pressing temperatures of 140, 150, 160, and 170 ℃. A mechanical testing machine, dynamic mechanical analysis （DMA）, and a scanning electronic microscope （SEM） were used to test the physical-mechanical properties, thermal stability, and bonding interface structure of composites. Results showed that when hot-pressing temperatures ranged from 140℃ to 150℃, obvious gaps between silane treated poplar veneer and plastic film were present. When pressing temperature increased from 140℃ to 160℃, increased （in MPa） tensile strength （1.27 to 1.89）, modulus of rupture （MOR） （63.90 to 72.20） and modulus of elasticity （MOE） （5 970.00 to 6 710.00） were noted. When pressing temperature increased from 140℃ to 170 ℃, water absorption （WA） decreased from 72.41% to 54.22% and thickness swelling （TS） from 4.98% to 4.09%. At 130℃when DCP content rose from 0 to 0.15%, the retention rate of the storage modulus increased from 62.31% to 92.01%. This also applied to the temperature for tanδmax which lagged from 144 ℃ to 200℃. In conclusion, silane modified poplar veneer/HDPE film composites have better physical-mechanical properties and thermal stability at 160 ℃. Because silane treated veneer can closely entangled with HDPE radicals generated by DCP under suitable pressing temperature, which contributed to forming stronger interface structure between the two phases. [Ch, 5 fig. 15 ref. ]