【作者】 赵君；

【导师】 王向明； 常建民；

【作者基本信息】 北京林业大学 ， 材料科学与技术， 2007， 博士

【摘要】 随着汽车工业的快速发展，废弃轮胎的“黑色污染”已经成为当今世界的突出问题和关注的热点。将废弃轮胎橡胶与木材制造功能性环保复合材料是合理利用废弃轮胎、解决“黑色污染”、节约木材资源的有效途径。本论文以落叶松（Larlx gmelini）木刨花和废旧轮胎橡胶为原料，采用异氰酸酯（Polymeric Methylene Diphenyl Diisocyanate，简称PMDI）和脲醛胶（Urea-Formaldehyde Resin，简称UF）混合胶粘剂研制开发出低成本、环保木质-橡胶功能性复合材料；深入系统研究了制备工艺和技术，探索了异氰酸酯、脲醛胶、木刨花与橡胶颗粒的配比水平、橡胶颗粒的尺寸、密度等因子对木质-橡胶复合材料物理力学性能的影响规律；运用多种数学统计分析方法，通过大量的实验和理论分析，对木质-橡胶复合材料性能的影响因子进行了优化，提出了最佳生产工艺；运用扫描电镜（SEM）分析手段研究了木质-橡胶复合材料的微观结构及其与材料力学性能的关系；运用现代测试手段对木质-橡胶复合材料的阻尼减震和隔声性能进行了检测分析，探索了其影响规律。主要研究结论如下：1．木质-橡胶复合材料的材料性能的主要影响因素为：木材与橡胶的配比水平、密度和异氰酸酯／脲醛胶的施胶量，其中：木材与橡胶的配比水平和密度对材料性能的影响极其显著，木材配比比例和密度越高，材料力学性能越好；PMDI／UF的施胶量对材料性能的影响较显著；橡胶颗粒尺寸对材料性能的影响极小；2．甲醛释放量（FE）的显著性影响顺序为：木刨花与橡胶颗粒配比水平＞脲醛胶树脂＞异氰酸酯胶粘剂＞橡胶颗粒尺寸，以全新的思想和理念开辟一条降低甲醛的捷径，取得甲醛释放量为7.1mg／100g的良好效果；3．根据复合材料力学性能和生产成本及效益对复合材料因子进行优化分析，获得制备木质-橡胶复合材料最佳优化组合为：木刨花与橡胶颗粒混合水平为60／40、异氰酸酯的水平为6％、脲醛胶的水平为10％、橡胶颗粒水平为5mm。这为木质-橡胶复合材料的工业化生产提供了科学依据和指导；4．通过工艺参数对MOR、MOE、IB影响的三维效果图的分析，得到密度、热压温度和时间工艺参数对木质-橡胶复合材料力学性能的影响规律、二次回归模型方程和最佳实验条件。研究发现：木质-橡胶复合材料的最佳制备工艺为：温度：170℃、时间：300Sec．、密度：1000ku m^-3；5．木质-橡胶复合材料的微观结构特征为：在木刨花之间，木刨花和橡胶颗粒之间可以形成良好的结合界面；对复合材料施加负荷过程中，复合材料形成密度剖面；木刨花／纤维破坏通常发生在高密度层或施胶量高的层中；木刨花／纤维拉长或从复合材料基体中拔出通常发生在低密度层或施胶量低的层中；6．木质-橡胶复合材料比普通人造板和常规的复合地板具有更好的阻尼减震和隔声效果，并且随着复合材料中橡胶颗粒配比水平的增加阻尼减震和隔声效果更显著。橡胶颗粒的大小对复合材料的阻尼减震和隔声效果也有一定的影响，可以根据木质-橡胶复合材料应用场所的不同以及对阻尼减震和隔声效果要求的不同，调整复合材料中橡胶颗粒的水平和橡胶颗粒的大小。更多还原

【Abstract】 With soaring development of automobile industry, problems of polluted environment and lack of resource are more and more remarkable in the globe. It is one efficient way to reducing "black pollution" and saving forest resources, which using waste tire and wood make new composite materials.Main purpose of the thesis was to that material comprising of larch (Larlx gmelini) wood particle and waste tire rubber, adopting a polymeric methylene diphenyl diisocyanate (PMDI) and urea-formaldehyde (UF) combination binder system manufacture low cost, environmental wood-rubber functional composite. Manufacturing technology was complete studied. Preceding parameter including PMDI/UF, wood particle-to-rubber crumb ratio, and size of rubber crumb, density, on the physical and mechanical properties of the composite panel have been fully developed. Optimization of processing variables in wood-rubber composites was performed by using some mathematical and statistic methods, based on a large number of trials, and optimal board manufacturing technology was obtained. Microcosmic structure of composite and relation between microcosmic structure and mechanical properties was probed by SEM. It is innovative study to probe the properties of damp shock absorption and sound insulation of wood/rubber composites. The main results and highlight from this study can be summarized as follows:1. The effects of main experimental variables, including PMDI, UF, wood particle-to-rubber crumb ratio, and size of rubber crumb, density, on the physical and mechanical properties of the composite panel have been fully investigated. The results indicated that the wood particle-to-rubber crumb ratio and density are the most significant variable that impacts on the composite performance. The physical and mechanical properties of the composite will be predominant with increacing wood particle-to-rubber crumb ratio and density, followed by the level of PMDI usage. The UF resin content and size of rubber crumb have a less influence on the panel properties.2. In terms of formaldehyde emission (FE) of the composite, the results showed that the ratio of wood particle and rubber crumbs is the most significant variable, followed by the UF content, The amount of PMDI has a less influence, while the size of rubber crumb has no influence on composite properties. The formaldehyde emission value (FE) was greatly reduced in the rubber-wood composite panel, and 7.1 mg/100g was obtained in this study.3. Based on the mechanical properties and cost analysis of composite panel and the optimal parameters of manufacturing composite panel were 60/40 wood particles/rubber crumbs, 6% PMDI, 10% UF, and 5-mm rubber crumbs. These results provide basic and useful information for commercial production of wood/rubber composite panel in the future.4. The board performance was evaluated by measuring internal bond (IB) strength, modulus of rupture (MOR) and modulus of elasticity (MOE). Based on the analyses of board properties, board density, pressing time and pressing temperature were identified as independent variables that had significant influence on board performace. A mathematical simulation or response surface models were developed to predict the board properties (MOR, MOE and IB). The suggested optimal board manufacturing conditions were about 170℃, for pressing temperature, 300 seconds for pressing time, and 1000 kg m～(-3) for board density.5. Microcosmic properties of structure in composite: interface areas in composite were performed between wood particle and wood particle, between wood particle and rubber crumb; Vertical density profile of wood/rubber composite panel was formed proceeding load affect on composite; wood particles/fibers usually were destroy in heavy vertical density profile and high level of PMDI/UF; wood particles/fibers usually were draw out or pull out from matrix in light vertical density profile and low level of PMDI/UF; 6. With advanced experimental methods and test facilities, damp shock absorption and sound insulation of composite panel were investigated. Testing results exhibited that wood/rubber composite panel has better damp shock absorption and sound insulation properties than wood-based particleboard. An increase in the quantity of waste tire rubber in the composite panel significantly improves damp shock absorption and sound insulation properties. The size of rubber crumbs also has certain influence on these board properties. Therefore, adjusting the quantity and size of rubber crumbs in the composite panel allows producing different quality panels for different applications.更多还原