Study On The Synthesis And Characterization Of Flame Retardant Copolyamide6

Nylon6are widely used in the industries of automobile, machinery manufacture,communications, daily necessaries and so on with its excellent mechanical properties andprocessing performance. However, as a kind of flammable polymer material, PA6has a limitingoxygen index value of23%and vertical burning test grade of V-2. When ignited, PA6burns fastand spread widely accompanied by a large amount of smoke and heavy dripping, which furthercauses fire disaster. Therefore, it is of great significance to develop a novel flame retardant PA6with outstanding comprehensive performance, in order to expend the applications of PA6.In this paper, CEPPA-HMDA was prepared by aminating2-carboxyethyl(phenyl) phosphinicacid (CEPPA) with Hexanediamine (HMDA), and its chemical structure, phosphorus content,thermal stability were characterized and the optimum reaction conditions were obtained. Theflame retardant PA6(FRPA6) was prepared by copolymerization with CEPPA-HMDA. Thechemical structure, phosphorus content of FRPA6was characterized and the effect of flameretardant on the crystallization properties, mechanical properties, thermal stability and flameretardant performance of FRPA6were studied.The main research results were as follows:(1) CEPPA-HMDA was generated by the reactionwith one amino in the end of HMDA and the carboxyl in CEPPA. And the optimum reactionconditions were as followed: n(CEPPA): n(HMDA)=1:1.1, the reaction temperature was70℃, thereaction time was5h and the yield of CEPPA-HMDA was up to96.27%. The onsetdecomposition temperature of CEPPA-HMDA was270℃, which met the copolymerizationtemperature of PA6.(2) The structure of CEPPA was appeared in the molecule chain of FRPA6besides the typical structure of PA6, which suggested that CEPPA had copolymerized in themolecule chain of PA6.(3) The crystal form of PA6didn’t change by introducing CEPPA.Whereas the grain size decreased and the crystalline properties were weakened. The tensilestrength and the elongation at break of FRPA6were lower than that of nylon6by the impact ofintroducing CEPPA.(4) The thermal decomposition of FRPA6was changed and the residue in 700℃increased. The LOI values were enhanced with the raising addition of CEPPA in FRPA6,indicating that the flame retardant of FRPA6was improved.