Preparation And Properties Of Liquid Silicone Rubber Via Amino-ene Reactions

In recent years,the development of silicone rubber is very rapid,and hundreds of brand new products have been prepared.Liquid silicone rubber which is an important species in the field of silicone rubber has been a hot topic of research and application.Now most liquid silicone rubber is based on the traditional mechanism of condensation,hydrosilylation and peroxide crosslinking.However,liquid silicone rubber is lack of the development of new crosslinking system research.What's more,the use of moisture curing and low temperature curing liquid silicone rubber is limited because of the influence of surrounding temperature and moisture.High temperature curing liquid silicone rubber has also been limited to application for its high curing temperature and the need of catalyst.Moreover high curing temperature also means higher energy consumption.Therefore development of new crosslinking system and stable temperature curing liquid silicone rubber are in urgent need for the research and application of liquid silicone rubber.Considering that the relationship between structure and property,the ammonia propyl polysiloxane with different molecular weight were prepared.The polymer has been characterized by infrared spectrum and nuclear magnetic spectra to determine its structure.And its molecular weight was measured by GPC.Non-aqueous titration method was used to determine the ammonia content.This work select the ammonia propyl to prepare new liquid silicone rubber base gum.Silicone rubber was synthezied by using trimethylolpropane triacrylate monomer,low molecular weight polysiloxane and low molecular weight silicone resin as the crosslinking agent with reinforcing filler.To optimize reaction conditions,the silicone rubbers with different reaction ratio,curing temperature,curing time and the type and dosage of filler were synthesized and measured their mechanical properties,and finally obtained the best formula of three kind systems.Through the research,we seek out the preparing silicone rubber's optimal conditions in 1,1,1-Trimethylol propane triacrylate system:the molecular weight of base adhesive is 21300g/mol,proportion of the group is 1:1.5,packing for ten copies of the brasque,curing under the optimum reaction conditions of 100? for 4 h;the optimal conditions for preparing silicone rubber in low molecular weight silicone oil system:the molecular weight of base adhesive is 21300g/mol,the content of crosslinking agent group is 12%,proportion of the group is 1:2.5,packing for twelve copies of the brasque,curing under the optimum reaction conditions of 120? for 5 h;the optimal conditions for preparing silicone rubber in low molecular weight silicone resin system:the molecular weight of base adhesive is 21300g/mol,the content of crosslinking agent group is 10%,proportion of the group is 1:3.0,packing for ten copies of the brasque,curing under the optimum reaction conditions of 120?for 5 h.Based on these above conditions we can get the optimal performance properties of silicone rubber.For 1,1,1-Trimethylol propane triacrylate system:the tensile strength of 1.62MPa,the tear strength of 8.63RN/m,elongation at break253%;for low molecular weight silicone oil system:the tensile strength of 1.68MIPa,the tear strength of 9.21 RN/m,elongation at break 245%;for low molecular weight silicone resin system the tensile strength of 2.95MPa,the tear strength of 10.95RN/m,elongation at break 368%.