热塑性复合材料原位聚合注射成型多组分树脂混合及其多尺度浸润过程

The application of lightweight, high strength continuous fiber reinforced thermoplastic composites is currently an important implementation for the strategy of energy conservation and sustainable development. However, the high material costs and low productivity are the major bottlenecks for the popularization of this type of materials. In this proposal, it is intended to study the following aspects for the manufacturing of the continuous fiber reinforced thermoplastic composites by injection molding with in situ polymerization, which are the influencing mechanism of the process parameters on the material properties under special molding conditions; the mechanism and characterization methods of on-line controllable mixing of the multi-component thermoplastic resin system; and the principle and control methods for the balancing of multi-scale infiltration flow. The aim of this study is to develop the key technologies for the manufacturing of high performance continuous fiber reinforced thermoplastic composites with high efficiency and performance on the basis of the current injection molding technology which has a relative higher degree of automation and comparatively mature process and equipment. It is supposed to provide theoretical guidance and technical support for the large-scale popularization and application of the continuous fiber reinforced thermoplastic composites. The main innovation of this proposal can be summarized as follows: The development of experimental device on the basis of a normal injection molding machine, which can be used for the feeding, transport, melting, metering, mixing and injection of the multi-component resin system. The proposal of the control method for the mixing efficiency and quality of the multi-component resin system; According to the principle of injection-compression molding process, a quantitative analysis model for the multi-scale infiltration flow will be built in the study on the principle and control method of the balancing of the macro and micro infiltration flow.

应用轻质高强连续纤维增强热塑性树脂基复合材料是践行当前节能减排与可持续发展战略的重要举措。而高昂的材料成本和较低的生产效率是制约该类型材料推广应用的主要瓶颈。本课题针对连续纤维增强热塑性复合材料的原位聚合注射成型技术，研究其特殊成型条件下材料性能的参数影响机理与规律、多组分低分子热塑性树脂在线可控混合机理与表征方法以及多尺度浸润流动平衡原理与调控方法。研究旨在依托自动化程度较高、工艺与装备较成熟的注射成型技术，发展高性能热塑性复合材料的高效、高质量制造关键技术，为实现其规模化推广应用提供理论指导与技术支持。主要创新点：基于现有注射成型装备，研制多组分树脂体系的喂料、传输、熔融、计量、混合、注射的试验装置，研究树脂与催化剂的动/静态混合机理，提出混合效率和质量的调控方法；基于注射-压缩成型工艺原理，研究宏观与微观浸润流动平衡原理和调控方法，建立多尺度融合的浸润流动定量分析模型。

连续纤维热塑性复合材料具有较高的韧性、冲击强度和可焊接、重复加工等优良性能，在航空航天、交通运输领域具有广泛的应用前景。然而，具有高熔点、高粘度特性的热塑性聚合物很难实现连续纤维织物的充分浸渍。基于低分子热塑性树脂体系的原位注射成型技术有望解决上述难题，其成功研发对于实现连续纤维热塑性复合材料的批量化制造，促进绿色环保型高性能热塑性复合材料的推广应用具有重要意义，是我国当前实现节能减排和经济结构转型战略的重大需求。本项目是我国在连续纤维热塑性复合材料批量化制造领域的一次有效探索，具体研究了原位注射成型条件下的低分子热塑性树脂体系的热力学性能，提出引用调和平均法修正接触角法表征界面张力新方法，获得了低分子热塑性树脂体系间的界面张力，得到了不同温度、催化剂锡含量和浓度配方条件下低分子热塑性树脂体系的粘时特性，为多组分树脂体系的在线混合机理、浸润流动平衡方法研究提供了参考依据和数据支持；基于层流流体运动的数学模型和稀物质的传输模型，采用数值模拟仿真研究了多组分树脂体系的静态混合过程，以分散相浓度的不均匀性系数为定量评价指标，获得了静态混合头混料芯单元螺旋角度、长径比、通道数量及雷诺数等参数对混合性能的影响规律，为多组分树脂连续熔融输送、在线混合装置的研制提供了理论参考；基于达西定律的一维流动方程，通过理论分析推导研究了树脂流动前锋运动的微分方程，得到了恒流量注射模式下注射压力与浸润时间之间的线性关系表达式和低分子热塑性树脂体系毛细作用压力降的测量方法，为原位注射成型多尺度浸润流动平衡试验研究提供了原理性指导。项目研究在连续纤维热塑性复合材料原位注射成型材料、工艺和装备方面取得了创新性进展，有助于推动连续纤维热塑性复合材料走向实际应用。迄今为止，本项目已发表论文3篇，其中SCI检索JCR1区论文2篇，录用EI论文1篇，授权发明专利1项，软件著作权1项，申请发明专利1项。