植物纤维表面可控疏水化改性及增强聚丙烯生物复合材料的研究

Bagasse and eucalyptus fibers are light, inexpensive, high-strength, renewable, recyclable and biodegradable. Cultivation and production of sugarcane and eucalyptus in extremely large scale were first produced in Guangxi, thus keeping Guangxi in leading position national-wide in this area. Polypropylene (PP) is a general-purpose plastics possessing excellent performance. Bagasse and eucalyptus fiber reinforced PP composites, leading to a range of biocomposites, have a number of advantages over classic composites reinforced by glass or carbon fiber, such as reducing costs, decreasing pollution, improving the performance of PP, and enhancing domestic economic development in agriculture sector. More importantly, the research targeting on the value-added products based on renewable and sustainable resources in the Province accords well with the current development trend of green economy. This project proposes a new surface treatment of plant fiber with water-based emulsion having core-shell structure and strong positive charge. The emulsion particles will be immobilized on the surface of plant fiber by electrostatic adsorption or association to render the surface of fiber hydrophobic so that the compatibility between plant fiber and PP matrix will be improved substantially. As a result, bagasse and eucalyptus fiber reinforced PP composites are expected to possess high performance or strength and suitable for various applications, including automobile parts and high-end furniture. Effects of type and adsorption amount of latex on the interfacial compatibility, and content and type of fibers on the mechanical properties of the composites will be studied. Meanwhile, the relationship between the microstructure and the mechanical properties of the biocomposites will be investigated as well. The findings from this research will have significant impact on promoting local economy via the utilization of natural or green resources for value-added products.

蔗渣和桉木纤维具有质轻、价廉、比强度高优势，同时具有可再生、可循环利用和可生物降解的环境友好性，广西甘蔗和桉树无论是种植量还是产量都居于我国首位。聚丙烯(PP)是一种具有很多优良性能的通用型塑料。蔗渣和桉木纤维增强PP生物复合材料与传统玻璃和碳纤维增强PP相比，可降低成本，减少污染，改进PP性能。本项目提出一种新的植物纤维表面处理方式，通过静电吸附原理，以带有较强正电性的核壳型水性乳液对植物纤维表面进行可控疏水化处理，将乳胶粒子固载于植物纤维表面，使植物纤维表面极性与PP基体材料极性接近，利用"相似相容"原理，制备出高性能蔗渣和桉木纤维增强PP生物复合材料。研究乳液种类、乳液吸附量对植物纤维界面相容性影响，纤维含量、纤维种类对复合材料力学性能影响，考察复合材料微观状态与力学性能关系。本项目研究将有助于我国尤其广西地区农业经济发展，实现资源有效利用及可持续发展，符合当前绿色经济发展趋势。

我国是仅次于巴西和印度的世界第三大甘蔗种植国，而广西是我国最主要的甘蔗和桉树种植大省，蔗渣纤维是甘蔗经过榨糖后剩下的主要部分，蔗渣和木纤维具有质轻、价廉、比强度高优势，同时具有可再生、可循环利用和可生物降解的环境友好性。聚丙烯(PP)和聚氯乙烯(PVC)是具有很多优良性能的通用型塑料。蔗渣和桉木纤维增强PP和PVC生物复合材料与传统玻璃和碳纤维增强PP和PVC相比，可降低成本、减少污染、改进PP和PVC性能。本项目提出一种新的植物纤维表面处理方式，通过静电吸附等作用，以带有较强正电性的核壳型水性乳液对植物纤维表面进行可控疏水化处理，将乳胶粒子固载于植物纤维表面，使植物纤维表面极性与PP和PVC基体材料极性接近，利用"相似相容"原理，制备出高性能蔗渣和木纤维增强PP和PVC生物复合材料。研究乳液种类、乳液吸附量对植物纤维表面疏水性的影响，纤维填充、纤维种类对复合材料性能影响，考察复合材料微观状态与力学性能关系。研究结果表明利用乳液疏水改性后的蔗渣纤维制备的植物纤维增强PVC生物复合材料在拉伸强度、断裂伸长率及抗压强度均有所提高，增强增韧效果明显；而利用乳液疏水改性后的木纤维制备的植物纤维增强PP生物复合材料的缺口与无缺口冲击强度和拉伸与弯曲强度也有显著的提高，达到了增强增韧效果，说明乳液疏水改性后的植物纤维既是复合材料的增强剂（植物纤维起主要作用）又是增韧剂（植物纤维表面上的乳胶薄膜层起主要作用）。复合材料的热分析结果表明植物纤维在其中确实充当了异相成核剂，使复合材料在更高的温度（即更高的Tc）下成核。本项目研究有利于植物纤维的资源化应用开发，将有助于我国尤其广西地区农业经济发展，实现资源有效利用及可持续发展，符合当前社会绿色经济发展趋势。