刚性粒子增韧聚合物体系的研究发展

刚性粒子增韧技术是制备兼具高刚性和高韧性的聚合物复合体系的有效手段 ,不仅具有重要的理论研究价值 ,而且具有广阔的应用前景和商业价值。本文综述了近 2 0年来有关刚性粒子增韧聚合物复合体系的研究概况 ,并着重讨论了刚性无机粒子增韧结晶性聚合物的增韧机理。大量研究表明 ,刚性粒子增韧聚合物的实现来源于两方面的贡献 ,其一是刚性粒子的引入所导致的局部应力状态的改变。通过脱粘、空化、三维应力约束的解除 ,为基体的剪切屈服提供应力条件。其二是刚性粒子对基体的结晶行为产生影响 ,使晶粒尺寸变小 ,完善程度降低 ,甚至在界面附近形成择优取向的滑移阻力较小的结晶层 ,从而促进基体发生屈服变形。基于大量的研究结果 ,作者指出最佳的增韧效果是适当的界面粘结强度 ,足够高的填料含量 ,基体较低的结晶度和屈服应力等因素所决定的。由此作者提出了刚性无机粒子增韧聚合物体系的界面设计方案。

Progresses in the Toughening of Polymers with Rigid Particles

In the present paper, the toughening mechanisms of polymers/rigid particle systems, especially that of polymer/inorganic particle composites, were reviewed. Massive studies have demonstrated that two aspects of factors contribute to the toughening. Firstly, the incorporation of rigid particles can result in changes in local stress conditions. With steps including the debonding between matrix and fillers, cavitation,the transition of stress states ahead the crack tip from plane strain to plane stress, the shear yielding of the matrix ligaments between particles and massive yield of matrix happened. Secondly, the existence of rigid particles may influence the crystallization behavior of polymer matrix, results in decreased crystallite size and degree of perfection, which in turn promotes the matrix undergo shear yielding rather than brittle fracture. It was suggested that from the point of view of material design, control the debonding of the particles occurs at proper opportunities is one important factor, and control the crystalline morphology of matrix by altering the interfacial interaction between the components is another important factor.