Preparation And Properties Of LLDPE/TPE Binary Blending Cable Materials

With the rapid development of the construction,transportation,information and other industriess,the demand for wire and cable is increasing and the application is more and more extensive.In this paper,a lightweight,cold resistant,halogen-free and fatigue resistant cable material was developed using linear low density polyethylene(LLDPE)/thermoplastic elastomer(TPE)as matrix resin.The cable material reduces the addition of inorganic substances by using synergistic flame retardant effect,which meets the national flame retardant standard and reduces the quality of products;Linear low density polyethylene(LLDPE)and thermoplastic elastomer(TPE)of two kinds of materials with good cold resistance,high toughness,this paper uses LLDPE and TPE such characteristics,produce a can in extremely cold environments,and can be a new cable material reciprocating bended anti fatigue ability is good;This new type of cable material will meet the requirements of PVC cable material which is not suitable for a wide range of applications in the market.This paper will utilize the linear low density polyethylene(LLDPE)/thermoplastic elastomer(TPE)as the matrix resin,developed a halogen-free flame retardant flexible cable materials,specific work will discussed as follows:(1)Study on processing technology and properties of LLDPE/TPE two component blendsUtilizing LLDPE and TPE as the matrix to explore the material mechanical properties which are based on the different proportions between LLDPE and TPE.Meanwhile,the processing conditions of LLDPE/TPE composites,and the thermal stability and compatibility of LLDPE/TPE composites are also researched.The results show that when LLDPE:TPE is 80:20,the tensile strength and elongation at break reach an optimum value,at which the tensile strength is 16.8MPa and the elongation at break is 960.4%;When the processing temperature of LLDPE/TPE is 140,the material has better mechanical properties,and the tensile strength reaches 20.3MPa at this temperature;LLDPE and TPE have low melting index,the melt index of LLDPE is 1.50g/10min,the TPE is 0.30g/10min,two yuan LLDPE/TPE blend melt index is higher than single LLDPE or TPE,and when LLDPE:TPE is 80:20,the melt index of two yuan LLDPE/TPE blend is 2.8g/10min,it increases nearly doubled than LLDPE as well as is 900%higher than TPE.In the industrial production,the melt index reflects the fluidity in the material processing,and the enhancement of the melt index makes the extrusion of the material in the processing process to enhance the ability of continuous profiles;Besides,it is found that these two kinds of materials of LLDPE and TPE are compatible with each other by SEM,and the TPE in the material exists in a three-dimensional network.The thermal stability of LLDPE/TPE composites increases with the increasing of LLDPE.(2)Study on halogen free flame retardant LLDPE/TPE composite with ATH/OMMT/NPSUsing LLDPE/TPE as the substrate,ATH as flame retardant,CRP?OMMT and NPS as synergistic flame retardant,adding POE-MA as matrix compatibilizer,the synergistic effect among ATH,OMMT and NPS and the effect of POE-MA on the dispersion of OMMT in epoxy matrix can be analyzed.The results show that the synergistic flame retardant effect exists among ATH,OMMT and NPS and uses this synergistic flame retardant effect to rematch flame retardant.This can not only improve the flame retardancy,but can also reduce the amount of inorganic flame retardant.The addition of a certain amount of poe-ma in LLDPE/TPE composite materials can help improve the dispersity of OMMT,thus making the separation layer formed in the combustion of OMMT more dispersing to improve the efficienc of flame retardant.It can be seen from the SEM diagram of composite carbon layer that the structure of the carbon layer formed by ATH,NPS and OMMT is more continuous and dense,and it has better insulation and oxygen isolation effect.According to the analysis of heat and weight curve,the carbon layer structure of the combination of ATH,NPS and OMMT is demonstrated in the side,which is more continuous and dense,and the protection of materials is better.(3)The effect of electron beam radiation on material performanceIrradiation by electron beam radiation of different radiation dose on materials,to investigate the effect of different radiation doses of heat shrinkable material mechanics,electrical and thermal properties.Through differential scanning calorimetry(DSC),multi crystal X ray diffraction(XRD),field emission scanning electron microscopy(SEM)to analyze the changes of material crystallinity,and the crystallinity of the composite was observed in the fracture surface morphology.The consequences show that the electron beam irradiation can make material of crosslinking,low irradiation dose can achieve high crosslinking density.However,when irradiation dose is oversize,the crosslink density increases slower.Considering the costs of production in industrial production and the production efficiency,LLDPE/TPE composite materials irradiation dosage should be 90 kgy relatively appropriate;The tensile strength of composite materials increased from 10.2Mpa to 12.8 Mpa,which increased by 25.5%.After the electron beam irradiation,the crystallization temperature and the melting temperature of LLDPE/TPE composite materials have been reduced;Actually,irradiation processing does not change the crystal type of LLDPE/TPE composites,but when the irradiation dose increases,the crystallinity shows the tendency of the first increased and then decreased;irradiation can improve the heat resistance and flame retardant of the composite material.