Radiation Crosslinking Modification Of Nylon 6

Currently,there are multiple modification ways used for nylon,and the ionizing radiation crosslinking modification is the most remarkable because of its unique advantage and mechanism.Mechanical properties,water resistence and thermal stability of irradiation crosslinking modified nylon material have improved.In this experiment,the triallyl isocyanurate(TAIC),trimethylallyl isocyanate(TMAIC)and divinylbenzene(DVB)was used as the sensitizer.The effects of sensitizer types,sensitizer loadings and radiation doses on the structure,mechanical properties,water absorption,and thermal stability of GF/PA6 composites were investigated.Differential scanning calorimeter(DSC),thermogravimetric analyzer(TG)and polar index tester were used to analyze the crystalline properties,thermal stability and flame retardance of the composites,respectively.The cross-linked structure of the composite and the carbon layer formed after combustion were oberserved with scanning electron microscopy(SEM).The results show that:(1)Sensitizer can improve the irradiation crosslinking efficiency of glass fiber/nylon 6 composites.The properties of composite are more excellent using TAIC as sensitizer.(2)Irradiation dose and sensitizer content plays an important role in the crosslinking of composite materials.(3)The tensile strength,flexural strength,and impact strength(at 25℃ and-20℃)of GF/PA6 composites are enhanced by 15.7%,43.2%,18.7%,and 17.3%,respectively,at a TAIC content of 1 wt%and a radiation dose of 50 kGy.(4)Jeziorny method and Mo’s equation can better describe the non-isothermal crystallization kinetics of the composites irradiation crosslinking.The crosslinking is not conducive to the growth of the crystal,and the formation of crystallization becomes difficult.(5)Radiation crosslinking significantly increased the decomposition temperature of the composites,and the residuals increased at 450℃.(6)The limit oxygen index of the composites after irradiation crosslinking increased slightly.During the pyrolysis process,the formed dense carbonized structure is effective in slowing down,even eliminating the formation rate of molten drops of GF/PA6 composites.