嵌段共聚物相容剂对聚合物共混体系力学性能影响的连续介观模拟

结合介观动力学方法和三维弹簧格子模型, 研究了嵌段共聚物相容剂对相容性较差的聚合物二元共混体系力学性能的影响. 在适当范围内不断增加嵌段共聚物相容剂的用量, 研究了相容剂含量对体系杨氏模数及拉伸强度的影响, 同时也对不同体系材料的破碎位点进行了分析. 结果表明, 未加入相容剂的二元共混体系在拉伸模拟中表现出较低的拉伸强度, 而适量添加相容剂可以显著提升材料的拉伸强度, 随着相容剂含量的增加, 共混体系的破碎位点会发生转移并最终改善材料的整体性能. 而相容剂的加入对体系杨氏模数的影响较小. 该连续模拟方法为关联聚合物复合体系的微观结构和宏观力学性能提供了一条高效的途径.

Sequential Mesoscale Approach for Determining the Effects of the Addition of a Block Copolymer Compatibilizer on the Mechanical Properties of Polymer Blends

The compatibilizing effects of the addition of a block copolymer on the mechanical properties of immiscible polymer blends were studied using a combined simulation method; this method used MesoDyn to determine the morphology and a probabilistic lattice spring model (LSM) to determine the mechanical properties. The mechanical properties, including the Young''s modulus, tensile strength, and fracture position, were analyzed as a function of the concentration of the additive. The simulation results showed that the polymer blends without any compatibilizer had poor mechanical properties, compared with the original components, primarily because of the lack of stress transfer across the sharp interface. The tensile strength increased dramatically with the addition of the compatibilizer. The fracture position moved from the interface further into the matrix with increases in the volume fraction of the compatibilizer, leading to the enhancement of the tensile strength. The Young''s modulus varied slightly with increases in the concentration of the additive. These studies provide an efficient path for the correlation of the complex morphologies of polymer blends with their mechanical response.