Preparation Of Isooctyl Copolymer And Its Plasticization On PVC Cable Compounds

PVC is widely used in cable industry because of its flame retardant,insulation,corrosion resistance and excellent mechanical properties.Besides PVC resin,plasticizers,stabilizers,flame retardants,inorganic fillers and other additives are usually concluded in the PVC cable compounds.These additives can be utilized to make up the insufficient performances of PVC under suitable additive amount.There are some problems to be solved in PVC cable compounds in practical application.For example,the heavy use of plasticizers makes PVC lower high flame-retardant standard and reduce the mechanical properties.Furthermore,plasticizers with low molecular weight are prone to migrate onto the surface of PVC materials,resulting in the concern of environmental pollution and public health.Based on these challenge mentioned above,the aim of this thesis is to design a PVC cable compounds formulation by using polymer plasticizer in an effort to obtain PVC cable materials with high flame retardancy,good toughness and plasticizer durability.In this work,the polymer plasticizers were synthesized,their effect on the mechanical properties of PVC,as well as on their compatibility with PVC was investigated.On the other hand,the basic formulation of the flame-retardant PVC cable compounds was designed.The as-synthesized polymer plasticizers were mixed with plasticizers with low molecular weight to produce a plasticizer mixture.The effect of the plasticizer mixture on the properties of the PVC cable compounds was studied.This paper mainly includes the following three aspects:1.The compatibility and mechanical properties of the PVC membranes blended with polyacrylate copolymers（EHA31,EHA42 and EHA54）,as well as PVC graft copolymers(GDPVC_1h,GDPVC_2hh and GDPVC_3h)were studied respectively.Except for EHA54,other five copolymers have good compatibility with PVC.The elongation at break of the blend membranes reach 136.8%,202.3%and 150.3%respectively as25phr of EHA31,EHA42 and GDPVC_3hh were added to PVC.2.The base formula with flame retardants was optimized by orthogonal experiment,and the effect of antimony trioxide on the performances of PVC cable compounds was tested based on the dominant combination of orthogonal experiment.The optimized addition amount of the flame retardants are determined as 10phr of antimony trioxide,10phr of zinc borate,12phr of basic magnesium carbonate,8phr of molybdenum trioxide,and 8phr of tricresyl phosphate.The flame-retardant PVC cable compounds according to this formulation exhibit Limiting Oxygen Index（LOI）of43.1,tensile strength of 18.3 MPa and elongation at break of 213%.3.After using the plasticizer mixture,it was found that the LOI of cable compounds reaches 43.6 when 9phr of GDPVC_3hh are added.The elongation at break of the cable compounds is as high as 226%when 9 phr of EHA42 are added.EHA31.The addition of EHA42 and GDPVC_3hh can effectively reduce the extraction and volatilization of PVC cable materials confirmed by durability test.