端羟基聚丁二烯与不同固化剂反应的实验与分子模拟

Experiment and Molecular Simulation of the Reaction between HTPB and Different Curing Agents

通过微观层面和宏观实验两种方法分别对端羟基聚丁二烯(HTPB)和不同固化剂反应的情况进行研究。使用福井函数中Hirshfeld charge电荷分布反映了官能团羟基(—OH)和异氰酸酯基团(—NCO)的电荷变化情况。N==C键长的计算揭示了反应过程中异氰酸酯基团(—NCO)上N==C键长成先增大而后趋于稳定现象;且通过搜索过渡态得到二苯基甲烷二异氰酸酯(MDI)、甲苯二异氰酸酯(TDI)的2位和4位异氰酸酯基团、异佛尔酮二异氰酸酯(IPDI)链上和环上的异氰酸酯基团的活化能分别为123.60 k J·mol^(-1)、157.82 k J·mol^(-1)和133.09 k J·mol^(-1)、223.30 k J·mol^(-1)和167.62 k J·mol^(-1)。此外,通过黏度测试方法得出HTPB-TDI、HTPB-IPDI和HTPB-MDI三种体系的黏度变化规律,从宏观层面上得出各体系反应快慢程度与模拟相同的结果,即HTPB-MDI>HTPB-TDI>HTPB-IPDI。

HTPB and different curing agent reaction conditions were studied by macro experiments and micro level simulations. The change of the charge of the functional groups（ —OH） and isocyanate groups（ —NCO） was reflected by Hirshfeld charge. The monitoring of N==C bond length revealed that the N = C bond of isocyanate group（ —NCO） in the reaction process becomes increasing and tends to be stable,and by the transition state search means. The energy barriers of Two phenyl methane diisocyanate（ MDI）,2 site and 4 site isocyanate groups of Toluene diisocyanate（ TDI）,isocyanate groups on the chain and ring of Isophorone diisocyanate（ IPDI） are 123. 60 kJ·mol^-1 ,157. 82 kJ·mol^-1 and 133. 09 kJ·mol^-1 ,223. 30 kJ·mol^-1 and 167. 62 kJ·mol^-1 could be known. At the same time,by monitoring the viscosity changes of HTPB-TDI,HTPB-IPDI,HTPB-MDI by macro experiment,the reaction speed is that HTPB-MDI 〉HTPB-TDI〉 HTPB-IPDI. The simulation results are agreement with the experiment.