Research On Structure And Performance Of One-step Silane Natural Cross-linked Polythene Cable Material

It is a great of vital significance for our country's social and economic development to study the cable,which is honored as blood vessels and nerves of country's social and economic development.In this paper,the structure and properties of cross-linked polyethylene cable were studied by the structure of polyethylene matrix material,the impact of water supply agents,crosslinking agents and crosslinking time,preparing one-step method silane cross-linked polyethylene(SCPE)cable.The SCPE cable material,relative to the market of warm water cross-linked polyethylene cable material,eliminates the warm water crosslinking process,with the advantages of energy-saving emission reduction.Adding different water supply agents to the linear low density polyethylene(LLDPE)and low density polyethylene(LDPE),one-step method SCPE was prepared,the comprehensive properties of which were investigated.Results showed that:First,the structure of polyethylene resin has great influence on the thermal shrinkage of cross-linked polyethylene,the larger the molecular weight,the longer the molecular chain,the higher the shear viscosity,the smaller the heat shrinkage rate.Second,zeolite powder group and zinc oxide groups on 7th day reached the degree of cross-linked and gel content,respectively 63%and 68%,and meet all the performance indicators.But the cable surface had poor quality,with small convex thorns;auxiliary crosslinking agent Triallylisocyanurate(TAIC)group not only can meet the performance requirements but also had smooth surface.LLDPE(7042):LDPE(2426H)=90:10 as matrix material,cross-linking agent masterbatch for 5phr,one-step silane natural cross-linking polyethylene cable material was prepared,and then was extrusion molded,sample prepared and placed at room temperature.All kinds of performance and its change law was test,and the result shows that:With the extension of cross-linking time,the tensile strength and gel content increased gradually,and reached a stable level of eighth days,24MPa and68%,respectively;Then,elongation at break,thermal elongation,cooling after permanent deformation rate and heat shrinkage rate gradually decreased with the extension of reaction time,after the 8th day to a stable,respectively,reached 620%,54%,1.7%and 2.8%,meeting the national standard requirements and market recognition;Through the DSC test,after cross-linking,the crystallization process appeared two peaks,and the high-temperature peak for LLDPE normal crystallization peak,and low temperature peak for the cross-linked structure.Along with the extension of reaction time,low temperature peak was more and more big,then peak height unchanged.The scan electron microscope(SEM)analysis of the morphology of the cross-linked polyethylene section,torque rheometer and infrared spectroscopy were used to measure structure,functional groups of different crosslinking time and average molecular weight(MC)of chain were calculated by cross-linking(sulfide)equation of state.And the result shows that:With the extension of the cross linking time,the fracture changed,and no rotor torque was increased gradually,and the final equilibrium was 195nm,and in the same sample thickness,the peak of the 1080cm^-1position of the characteristic functional group Si-O-Si with the extension of the crosslinking time is more and more strong.According to the equation of state,it is known that the M_C is gradually reduced with the extension of the cross-linking time.Finally,it is stable at about 8000g/mol,and the average of a PE molecule is linked to3-4.Influence of the pre impregnated time,temperature of preparation process technology of cable material on gel content.Through the cable extrusion die temperature of cable in extrusion molding process.Influence of gel content and water supply agent,cross-linking agent on the surface of the cable quality.And the natural crosslinking polyethylene rapid detection method was researched.And the result shows that:Pre immersion time shall not be less than 40min,pre impregnation temperature not lower than 80?,die temperature shall not be less than 180?.Then water agent in cable extrusion release water was uncontrollable,the surface was easy to generate small convex thorn,SCPE in warm water with the temperature of 90?,40 minutes can be reached the degree of crosslinking,which could be used in the actual production for rapid detection.