【作者】 许福；

【导师】 张平；

【作者基本信息】 湘潭大学 ， 一般力学与力学基础， 2005， 硕士

【摘要】 合金化是改性现有种类基础树脂,实现组分聚合物优势性能组合从而获得新的高性能聚合物的重要方法。聚合物合金材料是一类基体和分散相均为聚合物的特殊复合材料。当前对聚合物合金材料的研究主要在材料的制备、物理和化学表征、应用及开发,在力学方面的研究较少,主要在强度、韧性等的测量和比较以及简单的共混法则对材料力学行为进行解释。本课题组结合力学理论与高分子材料学科、物理学科的知识指导材料设计,成功发明了一种技术创新的原位制备聚合物纳米复合材料的新方法,基于均匀化方法、平均场理论等构筑了材料的多尺度结构模型,并用这一模型对典型部分结晶聚合物材料PA6 的宏观有效性能进行了研究。本文在此思想和理论启发指导下,制备了PA6/PTT 聚合物合金材料体系,并对材料进行了化学、物理表征和相关的力学测试,结合物理、化学检测结果,基于广义自洽Mori-Tanaka 理论构筑了PA6/PTT 合金材料的结构模型,通过组分相的微观力学性能对材料的宏观有效模量进行了计算,并与实验结果进行比较结果显示用细观力学模型能较精确地计算分散相体积分数较小时此类聚合物合金材料宏观有效弹性模量;由一维陈化理论,利用蠕变内应力对纯组分PA6 材料和PA6/PTT 合金体系在室温下蠕变行为的差异进行了解释,讨论了蠕变内应力提高材料抗蠕变性能的作用机制;通过力学性能的综合比较,PTT 质量分数20%时PTT 合金化PA6 具有相对较优的改性效果。更多还原

【Abstract】 Alloying (or blending) is a very important way for modifying the present existing basic resin. By alloying new polymers with high performance can be obtained through combination of superior properties of the component materials. Polymer alloy is a kind of special composite whose matrix phase and dispersed phase are all polymers. Nowadays, researchers generally place their interests on the preparation, physical and chemical characterization and application of polymer alloys. There are fewer studies relative to mechanical aspects of the materials except for some measurements and comparisons of strength and toughness, and using simple blending principle to estimate the mechanical properties. Combining mechanical theories with polymer material science and physical science, our workgroup has invented a technically innovative method to prepare polymeric nano-composites in-situ. Employing homogenization and mean field theory, multi-scale model is set up to study the mechanical behaviour of the nano-polymer-composites. Using the structural model, macro effective mechanical properties of typical semi-crystalline polymer such as PA6 has been studied Enlightened by these ideas and theories, typical polymer alloy, PA6/PTT, is prepared in the present research. Chemical and physical characterizations to the materials are performed to support the structural model constructed on the base of general self-consistent Mori-Tanaka theory. Macro effective modulus of the polymer alloys is calculated. Comparisons of the results with the experimental data indicate that micro-mechanical model is relatively satisfactory for calculating macro effective elastic modulus of the polymer alloys when volume fraction of the dispersion phase is low. Using creep aging theory, creep internal stress is introduced to explain the difference of creep behaviors between pure PA6 and PA6/PTT alloys at room temperature. Mechanism of internal stress on improving the creep resistance of the materials is discussed. By comparing the mechanical performance synthetically, alloying shows relatively better modifying effect when weight fraction of PTT is 20%.更多还原