Preparation Of SAN/CR Blend And Study On Its Structure And Properties

Styrene-acrylonitrile random copolymer（SAN）,as a kind of plastic with excellent performance,has many advantages such as large rigidity,good heat resistance,strong stress cracking resistance,etc.If the impact performance is improved or greatly improved and the flame retardant performance is further increased,it will be given more excellent performance.Chloroprene rubber（CR）is a kind of heat resistant oxygen aging,weathering resistant significantly better than other diene rubber,especially the large number of chlorine atoms in the molecular chain of CR,which gives CR excellent flame retardant properties.Therefore,CR can be used as toughening agent and flame retardant effect in SAN.Based on the SAN/CR blending system as the research foundation,this paper firstly studied the flame-retardant effect of various flame-retardant systems on SAN,and at the same time studied the characteristics and rules of reactive capacity increase of SAN/CR blending system.The main contents are as follows:1.The selection of antimony trioxide（Sb₂O₃）,ten bromine diphenyl oxide（DBDPE）of halogen-antimony flame retardant system,phenolic resin（PF）and triphenyl phosphate（TPP）expansion type flame retardant system,focuses on the use of the two kinds of flame retardant system of SAN/CR blend limit oxygen index（LOI）and vertical burning level（UL-94）,the influence of the notched impact strength,etc.The flame-retardant system with the best comprehensive performance is selected.2.Graft copolymer was prepared by grafting reaction between styrene（St）and acrylonitrile（An）monomers and CR matrix in Hapro torque rheometer by melting grafting method.The effects of temperature,amount of monomer,amount of initiator,and ratio of monomer on grafting reaction and gel rate were investigated.Using CR and CR modified by in-situ grafting to toughen and modify SAN respectively,the mechanical properties of the two blending systems were compared,and the dynamic vulcanization characteristics of the blends were investigated by measuring gel rate.3.Friedel-crafts alkylation of SAN/CR was carried out in the torque rheometer.The reaction law was studied,the influence of catalyst AlCl₃ was the most effective,and the influence of temperature and time on SAN/CR Crfriedel-Crafts alkylation was studied.Weighing method and infrared analysis showed that the reaction degree increased with the increase of reaction temperature and reaction time.The microstructure of various components of SAN/CR/AlCl₃ reaction system was analyzed by DSC,FT-IR,GPC and SEM.