Kinetics Analysis on the Polycondensation Process of Poly(p-phenylene terephthalamide): Experimental Verification and Molecular Simulation
The conventional low-temperature method of solution polycondensation was developed to realize the reaction of p-phenylenediamin and terephthaloyl chloride for the preparation of poly(p-phenylene terephthalamide) (PPTA). Some main factors influencing this process were investigated to determine the optimum condition for high molecular weight. Experiment showed significant slowing of the reaction and gradual deviation of second-order reaction kinetics due to diffusion control. These phenomena were studied theoretically via dynamic Monte Carlo simulation. A concise expression, X̅n ~ c0-0.88·t0.37, was proposed to describe the diffusioncontrolled polycondensation process as a function of the monomer concentration and reaction time. The theoretical results provided a good description of diffusion-effected kinetics for the polycondensation process of PPTA, and demonstrated good agreement with the experimental data. Some differences of scaling relations between model and experiment results were also discussed.
KeywordsPoly(p-phenylene terephthalamide) Molecular weight Reaction kinetics Molecular simulation
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This work was financially supported by the National Natural Science Foundation of China (Nos. 21204011, 51603120 and 21404023), the National Basic Research Program of the China 973 Program (No. 2011CB606101), Fundamental Research Funds for the Central Universities, Innovation Program of Shanghai Science and Technology Commission (No. 14521100605) and the Innovation Program of Shanghai Municipal Education Commission.
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