端羟基聚丁二烯与2,6-甲苯二异氰酸酯固化网络弹性力学性质的分子模拟

Molecular Simulation of Elastic Property for Solidified System of Hydroxyl Terminated Polybutadiene and 2,6-Toluenediisocyanate

采用最大熵模型,构建了HTPB预聚物的最可几结构.考察了HTPB(nC=9)与TDI全混合以及半混合的两种固化建模方式.分子动力学模拟得到的HTPB(nC=9)-TDI固化网络的N—N径向分布函数显示半混模式比全混模式的结构更均匀.采用分子动力学动态模拟与静态拉伸方法对HTPB(nC=9)-TDI固化网络进行弹性力学性质的模拟计算.比较了半混和全混模式对拉伸模量计算的影响,表明半混模式得到的固化网络能得到合理的模拟结果.初步表明最大熵模型在研究HTPB固化问题上静态或动态模拟结果都具有唯象可行性.

The prepolymer of HTPB with the most probable structure was built based on the maximum entropy principle. The full and partial mixing modes in the solidification of HTPB （nc=9） and TDI were in- vestigated. The radial distribution function of nitrogen-nitrogen atoms calculated by molecular dynamics simulation was used as the criterion for the homogeneity of the solidified product, and it is indicated that the product made by the partial mixing shows better homogeneity than that by the full mixing. The Young＇s module of the HTPB （nc=9）-TDI product was simulated by both molecular dynamics and static stretching methods. Its dependence on the mixing mode in the solidification reveals that the product made by the par- tial mixing mode gives simulation results comparable to experiments, no matter whether the simulation was performed by a molecular dynamics or a static stretching method. In short, the maximum entropy model was proved phenomenologically feasible in the molecular simulation of polymers.