SBR／TPU的分子动力学模拟及耐热性能

Molecular Dynamics Simulationand Its Thermal of SBR/TPU

为提高热塑性聚氨酯(TPU)的耐热性能,通过密炼共混、热压成型工艺,选取丁苯橡胶(SBR)对2种TPU进行物理共混改性,制备了TPU/SBR复合材料,探讨了TPU的不同软段结构对复合材料力学性能和热性能的影响,并结合分子动力学(MD)模拟分析不同软段结构TPU/SBR复合体系分子之间的相互作用。结果表明:聚酯型TPU比聚醚型TPU的力学性能好,热稳定性好;SBR的加入使得2种TPU的耐热性能均有提高,且聚醚型TPU/SBR复合材料的耐热性能大于聚酯型TPU/SBR复合材料,但它们的力学性能都有不同程度的降低。通过分子动力学(MD)模拟分析,相同比例下复合材料的Huggins-Flory相互作用参数(χ)和混合能(Emix),PTTPU/SBR均小于PCTPU/SBR,可以预测PTTPU与SBR两者具有更好的的相容性。对2种复合材料的径向分布函数的分析进一步证明PTTPU/SBR的相容性大于PCTPU/SBR的相容性,模拟结果与实验结果一致。

In order to improve the thermal stability of thermal plastic polyurethane elastomer （TPU） , the TPU/SBR composite were prepared through blending the styrene butadiene rubber （SBR） by physical blending modification. What＇ s more,the effect of TPU with different soft segment structure were studied by mechanical and thermal properties of the composite. And the interaction between the molecules of different soft segment structure TPU/SBR composites combined with molecular dynamics （MD）simulation was analysised. The results showed that the mechanical properties and thermal stability of polyether TPU was better than the polyester TPU and the thermal performance of two kinds of TPU had improved by adding SBR. But the heat resistant performance of polyether TPU/SBR composite was better than that of polyester type TPU/SBR composite. And mechanical properties of TPU/SBR composite had reduced in different degrees. By means of molecular dynamics（MD） simulation analysis, Huggins-Flory interaction parameter（x） and mixing energy（ Emi~ ）of PTTPU/SBR were less than that of PCTPU/SBR. It was predicted that PTTPU and SBR had better compatibility. The analysis of the radial distribution function of the two kinds of composite further proved that the ompatibility of PTTPU/SBR is more than PCTPU/SBR. The simulation results were in agreement with the experimental results.