贵州省优势木种纤维增强HDPE复合材料物理、力学和蠕变性能研究

This project will exploit the advantages of preponderant arbor forest resources in Guizhou Province. The thermoplastic resin composites reinforced by wood processing residues and wood powder from Chinese red pine and Chinese fir were prepared. This applied basic research centers around physical, mechanical and creep properties of the resulted composites. The density, hardness, absorption ability, flexural property, tensile property, impact strength, physical, the morphologies of the impact fracture section, long-term creep and short-term creep-recovery properties were tested were analyzed by modern scope, measuring, test, analytical instruments and mathematical analysis method, beginning with altering the components and dosage proportion of two kinds of wood. The effect laws of chemical composition, dosage form, morphology and modification methods of two kinds of wood fibers to properties of composites were clarified, in order to seek the best formula to improve the properties of wood plastic composite and the accurate and applicable mathematical model of prediction for the properties of wood plastic composites. All the experiments will be carried out in Guizhou Minzu University and the Key Laboratory of Bio-based Materials Science & Technology Ministry of Education Northeast Forestry University, where has all the equipment needed for research. The project has an important economic and social benefits of effective comprehensive utilization of machining residual waste of tree species resources in Guizhou Province and waste plastics. It was expected that the proposed two different processes of materials preparation,and published 3-5 papers.

本项目发挥贵州省的乔木林资源优势，利用木材加工剩余废料马尾松和杉木的木粉增强热塑性树脂制备复合材料，围绕复合材料的物理力学性能和蠕变性能展开应用基础研究。从两种木粉的组分构成和用量比入手，借助现代观察、测试、分析仪器和数理分析手段，通过对复合材料的体视显微镜观察、密度测试、硬度测试、吸水性能测试、弯曲测试、拉伸测试和冲击测试、扫描电镜下冲击断面的观察以及长期蠕变性能测试和短期蠕变-回复性能测试，阐明各树种木粉化学组分构成、用量、形态、改性方法对复合材料性能的影响规律，以寻求提高木塑复合材料性能的配方，从而为木塑复合材料性能的预测提供准确适用的数理模型。实验拟在贵州民族大学和东北林业大学生物质材料科学与技术教育部重点实验室进行，基本具备研究所需的全部设备。研究对有效综合利用贵州省特色树种资源的加工剩余废料和废旧塑料具有重要的经济和社会效益。预计提出材料制备新工艺两种，发表论文3-5篇。

为了更好地利用贵州省主要森林抚育间伐、木材加工剩余物，达到缓解环境污染、提高材料附加值、创造良好经济效益的目的，采用挤出成型法制备马尾松木粉/杉木木粉/高密度聚乙烯（HDPE）复合材料，研究马尾松和杉木木粉质量比对复合材料的物理（密度、颜色、尺寸稳定性）、力学（弯曲、拉伸、冲击性能、动态力学性能）和蠕变性能（24 h蠕变-24 h回复性能和1000 h蠕变性能）的影响。寻求优化配方，并为该类复合材料性能的预测提供准确适用的数理模型。.研究结果表明，减小马尾松和杉木的质量比，复合材料的密度相差不大，而表面明度值和黄蓝轴色度指数均呈现减小趋势；杉木木粉/HDPE复合材料的吸水尺寸稳定性较好，24 h吸水率和吸水厚度膨胀率分别为2.412%和1.411%，更适合在户外潮湿环境中使用；随着马尾松木粉含量从60%逐渐减小到0，复合材料的储能模量升高，损耗模量和损耗角正切值降低，力学性能逐渐增强，静曲强度（MOR）和静曲模量（MOE）分别提高了47.58%和25.00%，拉伸强度和拉伸模量分别提高了92.52%和120.00%，冲击强度提高了70.03%。引入成分对复合材料性能的贡献因子作为参数修正ROM模型预测该种复合材料的物理、力学性能，效果优于传统的ROM模型、IROM模型和Hirsch模型。马尾松木粉含量高的复合材料的短期蠕变较小，而马尾松木粉含量为40%的复合材料长期蠕变较小，是作为防蠕变材料的最佳选择。Findley指数模型模拟复合材料的24 h和1000 h蠕变行为的效果优于两参数指数模型，并提出Burgers模型可能是更好的选择。12个月的室内老化使复合材料的材色变暗且向红色和黄色方向移动，而12个月的户外老化使复合材料的材色变亮且向绿色和蓝色方向移动。复合材料的拉伸性能受老化影响较为显著，户外的环境加快了复合材料的老化降解速率。杉木/HDPE复合材料的耐老化性能均优于马尾松/HDPE复合材料。本项目研究对有效综合利用贵州省特色树种资源的加工剩余废料和废旧塑料具有重要的经济和社会效益。