The Effect Of Radiation Induced In Situ Compatibilization Of Polymer Alloy

Five polyethylene terephthalate（PET）alloys were prepared by radiationinduced in situ compatibilization. The mechanical properties，gel fraction andscanning electron microscopy were studied before and after radiation.Comparing the mechanical properties of PET/POE and PET/SEBS alloy,without TMPTA and radiation, the SEBS had better toughening effect than POE.Because SEBS had benzene ring and lower melt viscosity, it more easily dispersedin the matrix. Adding TMPTA and radiation, the TMPTA were involved in radicalreaction of PET alloy. When the amount of TMPTA was about1wt%, crosslinkedstructure may be formed between the PET and the POE or SEBS. The impactstrength of PET alloy system was improved due to the increasing of the two-phaseinteraction. When the content of TMPTA was greater than5wt%, it not onlyformed the crosslinked structure between the two phases, but also producedself-crosslinking which influenced interfacial compatibility and resulted theimpact strength of the PET alloy to decrease, thus the the preferred amount of gelwas5%. For PET/POE/TMPTA and PET/SEBS/TMPTA alloy systems, thepreferred amount of TMPTA was1wt%. When the amount of TMPTA was1wt%and toughening agent was5wt%, the radiation-induced self compatibilization ofTMPTA was not obvious, so at the toughening effect of SEBS was better thanPOE.When the toughening agent was more than10wt%, the toughening effect ofPOE was better than SEBS. When the toughening agent increased to15wt%, theimpact strength of the PET/POE alloy was improved by200%compared to purePET, as the impact strength of PET/SEBS alloy can be increased by100%. Fromthe change of the fracture surface of the two alloy systems (PET/tougheningagent/TMPTA=85/15/1) before and after irradiation, the interfacialcompatibilization of PET and toughening agent was improved and the size of thedispersed phase reduced significantly which also proved the occurrence of radiation-induced self-compatibilization effect.Comparing the PET/POE and PET/POE-g-MA alloys, it was found that thereaction of irradiation and functional group was equilibriumto the reaction of MAand PET, which was difficult to produce a synergistic effect as POE-g-MA contentwas5wt%. When POE-g-MA content increased to15wt%, the two reactionsoccurred in synergy so that the toughening effect of POE-g-MA was much betterthan the POE due to the synergistic effect; When TMPTA content was3wt%andthe absorbed dose was100kGy, the impact strength of PET/POE-g-MA alloysincreased by350%, and the electron micrograph also showed that the dimensionsof POE-g-MA significantly smaller and more blurred with the PET substrateinterface. So when POE-g-MA content was15wt%, the compatibility between thetwo-phase interface has been enhanced due to synergistic effects.Comparing the PET/SEBS and PET/SEBS-g-MA alloys, it was found that thetoughening effect of SEBS-g-MA was lower than SEBS. When the tougheningagent content was15wt%, the impact strength of PET/SEBS-g-MA alloy systemwas up to55%, while the PET/SEBS alloy could improve about120%. Electronmicrographs alsoshowed that PET/SEBS-g-MA alloy afteradding TMPTA and irradiation, large particles still exist between SEBS-g-MAand PET interface, and capacity sex had not been effectively improved.Comparing the impact strength of five PET alloys, it was found that differenttoughening agent have different radiation-induced self-compatibilization effect.The structure of toughening agent could influence the toughening effect on PETalloys.A series of high strength and high toughness PET alloys were prepared withPOE-g-MA as toughening, TMPTA as cross-linking agent and basalt fiber (BF).The amount of POE-g-MA was10-15wt%, TMPTA was2wt%, BF was16-20wt%, and the absorbed dose was10-30kGy. It can be seen the surface ofthe fiber cross-section was covered with the matrix resin material and fracture ofmatrix resin was mainly fracture toughness. The interphase force of PET alloywas improved significantly due to the effect of radiation induced in situ compatibilization. And the main performance of PET alloys reached theadvanced level of similar materials.From the phase structure and mechanical of irradiated EVOH alloys andnylon alloys, the effect of radiation induced in situ compatibilization of polymeralloy has universal applicability.