微孔发泡聚合物材料力学行为的研究

The microcellular foam polymer materials was made using chemical foam injection method, evolution law of the cell shape, cell diameter and cell distribution were studied in loading by morphological characteristics analysis and theory of digital image analysis, according to deformation process and failure process of cell, effect of mechanical behavior on failure mechanism of cell and micro defect structure was analyzed. We use ANSYS software to set up stress-strain model of cell near by experimental research data, which was forecasted for relevance of cell structure and mechanical properties. Physical and mathematical models was build by the strength and toughness of resin, the effective bearing area and stress strain field distribution characteristics of microcellular materials, effect mechanism of intrinsic properties and cell structure on the mechanical properties of the composites was analyzed using physical and mathematical models. Reinforced by surface modified and gas diffusion behavior of molten resin were studied by microcellular foaming technology and compatibility technology, revealed strengthening and toughening mechanisms of microcellular polymer materials in vapor-melt phase-enhanced phase condition, it provide production and application guide for microcellular polymer materials.

项目以化学发泡注塑成型法制备微孔发泡聚合物材料，将数字图像分析理论和形态学特征分析法相结合，分析孔尺寸、孔形态、孔分布在荷载作用下的演化规律；结合可观察变形的形成过程和各个孔的破坏过程，进一步探索孔的失效机理及微缺陷结构对微观力学行为的影响；并进行仿真与模拟，对泡孔尺寸大小及拓扑分布与微孔发泡材料力学性能的变化规律进行预测。根据树脂本征强度和韧性、微孔材料受力时的应力应变场分布特征、以及孔材料受力时的有效承载面积等因素建立物理数学模型，分析和预测本征特性和孔结构对材料力学性能的影响机理。同时通过微孔发泡技术和相容性技术，对增强相表面修饰和熔融树脂中气体扩散行为进行研究，抑制熔体相、增强相、气相三相共存条件下气相沿增强相界面的扩散和偏聚，揭示其气相-熔体相-增强相条件下微孔发泡聚合物材料填充增强增韧机制，为微孔发泡聚合物材料的生产和应用提供指导。

以数字图像分析理论和形态学特征分析法为基础，分析了孔尺寸、孔形态、孔分布在荷载作用下的演化规律，结合可观察变形的形成过程和各个孔的破坏过程，探索了泡孔的失效机理及微缺陷结构对力学行为的影响规律，发现细小而均匀的泡孔对发泡材料的强度和韧性都有明显的提高。选取通用树脂聚丙烯（PP）和聚苯乙烯（PS）材料发泡后，根据树脂本征特性、微孔材料受力时的应力应变场分布以及孔材料受力时的有效承载面积，建立了物理数学模型，分析和预测材料本征特性和孔结构对材料力学性能的影响机理，揭示了不同本征特性树脂发泡后报道不尽相同的机理。对PP/GF发泡复合材料进行研究发现，在气相存在条件下，PP/GF的界面行为、GF在树脂中的迁移行为以及材料本身发泡质量对抑制气相沿增强相界面的扩散和偏聚有较大影响，从而影响GF在发泡聚合物材料中的增强增韧作用，揭示了气相-熔体相-增强相条件下微孔发泡聚合物材料的增强增韧机制。因此，本项目物理数学模型的建立对微孔发泡聚合物材料的设计提供理论参考。为发泡质量改善提高力学性能提供了新的思路和方法。为高性能发泡结构材料的增强增韧设计制造提供理论依据。为工业化生产微孔发泡聚合物材料制品坚定理论和实践基础。