Preparation And Properties Of Melt Processable Acrylonitrile Copolymers Without Plasticizer

By co polymerization between a flexible co-monomer and acrylonitrile reduces the melting point or increases the decomposition temperature in order to produce melt processable resin.This resin can be further melt processed to form fiber.In our study, 5-30mol%of methyl acrylate(AM),vinyl acetate(VAc)and acrylamide(AM)were separately adopted as co-monomers to co polymerize with acrylonitrile(AN).At the step of redox polymerization,the microencapsulated n-octadecane was incorporated into the co-polymer matrix.The structure and properties were studied by using FTIR, SEM,~1H NMR,DSC,TG-DTA,XRD,GPC and Ubbelohde viscosimeter.The results show that:1.The molar ratios of MA and VAc in the copolymers are slightly lower than the theoretical value,which is calculated from the raw material ratios.The molar ratio of AM is slightly higher than the theoretical value.2.The decomposition temperature of AN/MA increases and the melting point appears below the decomposition with the increase of MA molar ratio.The decomposition is 338.8℃and the melting temperature is 188.8℃when the molar ratio of MA is 30mol%.3.The melting point of AN/VAc copolymers decreases and the decomposition temperature rises firstly and then descends.The decomposition temperature is 364℃and the melting temperature is 221℃when the molar ratio of VAc is 10mol%. 4.The decomposition temperature of AN/AM decreases firstly and then increases with increasing the molar ratio of AM.The decomposition temperature drops to 237.7℃when the molar ratio of AM is 20mol%.The quantity of exothermic heat decreases firstly and then increases.The presence of AM induces to change the cyclization mechanism of copolymers from free radical to ionic.5.As the content of MA and/or microcapsules increases,the melting temperature decreases to 203℃and the decomposition temperature rises up to 303℃.6.The melting point of copolymers of AN/VAc decreases to 266.8℃while the decomposition temperature increases to 366.8℃with the increase of VAc molar ratio and/or microcapsules content.7.When the microcapsules content is constant,the decomposition of copolymers drops firstly and then increases with increasing the molar ratio of AM.When the molar ratio of AM is kept constant,the decomposition temperature of copolymers increases with the increase of microcapsules content.The melting point decreases with the increase of AM and /or microcapsules content.The melting point of 80/20 AN/AM co-polymer is only 183.5℃when the content of microcapsules is 30wt%.8.The crystallinity of copolymers decreases with the increase of molar ratio of co-monomers and/or microcapsules content.9.The melting point of acrylonitrile based copolymers drops due to the incorporation of MicroPCMs.MicroPCMs increase the free volume between the molecular chains.The melting point of AN/MA copolymers containing microcapsules is depressed to 206℃,which is lower than that of Amlon(225℃).It is the theoretical base to obtain the melt processable acrylonitrile copolymers.