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

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tanδ_max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。图5参15

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

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 composites 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 tanδ_max 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.]