Electron Beam Radiation Cross-linked PE/EVA Based Heat Shrinkable Materials And Their Properties

Heat shrinkable materials are intelligent polymer material,they have been widely used in electricity,transport and automotive sector because of their intelligence,reliability.With the development of urbanization and economic,the demand of high-performance heat-shrinkable material was gradually expand in domestic market.Most conventional heat shrinkable materials were perpetrated by a thermoplastic rubber and elastomer.The acquisition of related raw materials was heavily dependent on imports,thus limiting its scope of application.The Heat shrinkable materials have higher requirements on the performance then cable materials.Based on this,the EVA/HDPE binary blend sensitized cross linked by Radiation were studied:1,Study on the Electron Beam Sensitized Irradiation Cross-Linking of HDPE/EVA BlendTriallyl isocyanurate(TAIC)was used as cross-linking sensitizer.High density polyethylene(HDPE)and ethylene-vinyl acetate copolymer(EVA)blend was radiation cross-linked by electron beam.The relationship between mechanical properties of the blend,degree of crystallinity and electrical properties as well as the degree of cross-linking under different radiation dose and TAIC content were studied.The results showed that:TAIC added significantly reduce radiation dose and higher gel content was got;TAIC added at 1%,and radiation dose 120KGy,the tensile strength of the composite reached 15.79MPa,elongation at break reached 475.4%.Further,the electron beam radiation does not alter the crystalline form of the composite material with increasing radiation dose,the crystallization temperature of the composite material,the melting point,the dielectric constant decreased;a slight improvement in thermal stability,optimal dielectric loss dose was achieved at 120KGy.2,The research of MH/ATH Complex and halogen flame retardant EVA/HDPE CompositesIn HDPE/EVA matrix,MH/ATH were as based flame retardant,EVA-g-MAH as matrix compatibility agent to MRP,ZB,OMMT synergistic flame retardant.To investigate the effect of different flame retardant material on the EVA/HDPE binary blend mechanical properties,processability and flame retardancy,the results showed that:MH/ATH = 60/20,ZB = 10,RMP?6,OMMT =10,the composite material has good mechanical performance and good flame retardant properties;Add EVA-g-MAH compatibilizer to improve the mechanical properties of halogen-free flame retardant system,tensile strength was improved to 8.82MPa and breaking elongation was improved to 325%adding 10 parts of EVA-g-MAH,decomposition temperature of MH was higher than ATH,and the ability to promote the char matrix better than ATH,OMMT promotes compact carbon material layer to form during the combustion;EVA-g-MAH improving the compatibility of the interface and inorganic particles,SEM shows relatively smooth fracture appearance.3,Study on properties of Heat Shrinkable materials by Electron beam irradiationHeat Shrinkable materials were irradiated by different radiation dose electron beam irradiation.To investigate the effects of different doses of radiation to Heat Shrinkable materials,electrical and thermal properties were studied by differential scanning calorimetry(DSC),multi-crystal X-ray diffraction(XRD),the cross-sectional surface morphology was observed by scanning electron microscope(SEM).The results show that:the tensile strength of the material was increased to 10.5MPa and elongation at break was 310%in the 90KGy radiation dose.Gel content and the crosslink density of heat-shrinkable material was increasing with radiation dose increases,the growth trend slowed after a radiation dose greater than 90KGy.The crystallinity of heat shrinkable materials was decreased as the radiation dose increased.The thermal stability of the heat-shrinkable material was increased by Electron beam radiation.The DMA and SEM showed good compatibility after radiation.Dielectric thermal analysis showed that the dielectric strength of the material was greater than 67KV/mm.