The Add Molding Room Temperature Vulcanized Silicone Rubber Impression Material

The silicone rubber impression material with room temperature vulcanizing compared with traditional impression materials,has the advantages of simple operation,high accuracy of impression,curing process does not produce by-products,deep curing,the curing time is easy to control ect,and has been widely used in electronics,electrical appliances,medical equipment,machinery manufacturing and so on.Domestic study of add molding room temperature vulcanized silicone rubber material is relatively small,low product maturity,especially in the field of dental impression material,the domestic many physicians are still using alginate material for clinical impression,this kind of impression material in stamping process prone to infiltration and overflow phenomenon,lead to changes in stamping die size.So it is very necessary for add molding room temperature vulcanization silicone rubber were studied and improved,make it show a good applicability in various fields appear.The research work of this thesis is divided into three parts,the first part is the synthesis and modification of raw materials;including vinyl end silicone oil preparation,and infrared characterization of the prepared vinyl silicone oil.Using Karstedt method,the platinum complex catalyst was prepared by the reaction of the Chloroplatinic acid and Divinyl tetramethyl disiloxane.The platinum complex has higher reactivity,can satisfy the requirements of catalyst for preparing impression material.And carry out surface treatment for fumed silica with the "dry" surface treatment processing.The second part is the preparation of silicone rubber impression material;With vinyl silicone oil,silicone oil containing hydrogen and phase silica,liquid paraffin,Pt catalyst as raw material,40.5% of vinyl silicone oil,4.5% of hydrogen containing silicone oil,45% of silicon powder,liquid paraffin9.97% and 0.03% Pt catalyst was prepared for the molding room temperature vulcanized silicone rubber impression materials.It can meet the requirements of impression material.The third part for vinyl phenyl silicone oil is added in the vinyl terminated silicone oil.The results show that the introduction of the phenyl group can improve the tensile strengthand hardness of the prepared silicone rubber,and the linear structure of ethylene basic silicone oil was replaced with three-dimensional structure of vinyl phenyl silicone resin,the synthesis of silicone rubber has better mechanical properties.