Research Progress on Rheological Behavior of Wood-Plastic Composites | 木塑复合材料流变行为研究进展

中国人. 木塑复合材料（WPC）是一种兼具有木材和塑料双重优点的新型复合材料,在建筑、家具、装饰、运输和汽车内衬等领域显示出独特的优势并得到了迅速发展。为了进一步降低成本和增强木质感,商业化WPC产品的木质纤维填充量在40%～60%,甚至超过70%。这种高的木质纤维填充量造成了WPC挤出加工困难,主要表现为不稳定流动及表面撕裂等现象的出现,由此导致产品质量差,加工效率低。目前,人们对这种高填充体系下WPC熔体的流变行为尚不完全理解,更是缺乏系统的理论基础。高填充体系下WPC熔体中木质纤维材料与木质纤维材料之间、木质纤维材料与聚合物基体之间相互作用增强,其中木质纤维材料（种类、尺寸、填充量）、聚合物基体的分子质量和分子质量分布、润滑剂、偶联剂都是该复杂体系流变行为的重要影响因素。本文对高木质纤维填充体系下WPC的流变行为研究进行系统回顾,以期为WPC的配方设计、工艺控制、加工设备升级和模具制造提供一定的理论基础和科学依据。

英语. Wood-plastic composite （WPC） is a novel material bearing excellent properties from both wood and thermoplastic. It is increasingly used in construction, furniture, decoration, transportation and interior of car. In order to reduce the cost and improve the wood texture, the wood content of commercial WPC has reached a level of 40% - 60% , even greater than 70%. The high wood content causes a difficulty in extrusion processing of WPC, where the flow of melt is unstable and the surface of extruded WPC exhibits a tear phenomena. In addition, the quality of WPC and the processing efficiency also decrease. Up date, the rheological behavior of highly filled WPC melt is still not fully understood due to lacking of the systematic theoretical basis. When plastic matrix is filled with high content of wood fiber, the interactions of fiber-fiber and fiber-polymer will enhance. In this complex system, dominant factors of rheological behavior include the lignocellulosic material （species, particle size, and content） , the molecular structure of the polymer matrix （ molecular weight and molecular weight distribution） , lubricants, and coupling agents. In this paper we reviewed the previous studies aiming at providing a theoretical and scientific foundation for proper formula design, process control, processing equipment upgrade, and die manufacture of WPC.