Studies On Copolymerization,Properties And Structure,Application Of N-substituted Maleimide And Analysis By The Fourth Statistical Mechanics And Chaos Theory

Materials are the foundation of science and industry. The research and application of new materials that has high mechanical properties, special function, and higher practical value have become a active field. In recent years, with the fast developing of polymer materials, the thermal properties of polymer materials become more and more important. Because of it's superior thermal properties, the studies on the synthesis and properties of copolymers of N-substitud-maleimide became more and more active.The thermal properties of polymers include two aspects. The first one is related to deformation, thermal capacity and other mechanical properties. The exchange of these physical quantity is coaused by the movement of macromolecular chain or chain segments. This kind thermal properties were characterized as softening point, glass transition temperature, melt point etc.. The second is related to chemical reactions such as decomposition, degradation etc.. This kind thermal properties were characterized as decomposition temperature, weight loss temperature etc..The thermal properties of polymers are determined by the molecular chain structure. There are three ways to improve the thermal properties of polymers: to introduce polar group to the molecular chain, to introduce heteroaromatic ring, and curing. Blending and composting are also the main ways to improve the thermal properties of polymers.N-substitued maleimides have become interesting monomers, which can be either radically copolymerized with other vinyl monomers or homopolymerized by way of radical or anionic polymerization in spite of their 1,2-disubstitued ethylene structure. Many works on their radical polymerization and copolymerization have been performed so far because of the superiority of their polymers or copolymers in thermal stability. But the studies on this kind polymers or copolymers seldom reported in our country.In this work, N-phenylmaleimide was synthesized by one-step method. The yield is 90% which higher than the reference value (70%).Terpolymers of MMA/N-PMI/AN, MMA/N-PMI/St, and St/N-PMI/AN at different feed content were synthesized by semibatch emulsion copolymerization (grandue addition of monomers ). The results show that the latex copolymerization procedure has a great influence on the copolymer structure and properties. For instance, semibatch copolymers were homogeneous, showing a single Tg, while the batch products ( single addition of monomers ) were heterogeneous, exhibiting two Tg's. The homogeneous structure was also proved by elemental analysis results.The thermal stability of copolymer was improved due to N-phenylmaleimide. The decomposition temperature, Vicat softening temperature, and glass transition temperature of terpolymer of MMA/N-PM1/AN (65:30:5) is 42.7 , 14.4, and 30 higher than PMMA, respectively. The decomposition temperature, Vicat softening temperature, and glass transition temperature of terpolymer of MMA/N-PMI/St (75:20:5) is 50, 14.0 , and 32.5 higher than PMMA, respectively. The decomposition temperature, Vicat softening temperature, and glass transition temperature of terpolymer of St/N-PMl/AN (75:20:5) is 50, 18.0, and 36 higher than PSt, respectively. The relationship of thermal properties of copolymers with N-phenylmaleimide was also determined in this work.The mechanical properties (tensile strength and impact strength) a"nd rheological behavior were also investigated in this work. For improving the mechanical properties, the third monomer was introduced to the copolymerization. The results show that not only the mechanical properties, but also the thermal properties and rheological behavior have improved when the third monomer (AN or St) was introduce to the copolymerization. It should be noted that the comprehensive properties of terpolymers are higher than PMMA and PSt.The terpolymer not only was used as polymer materials, but also was used as heat resistant modifier. The thermal properties of polymer materials can be improved by blended with N-substitued maleimide cantaining terpolyme...