Preparation And Properties Of Polysiloxanes With Side-Sulfone Groups

Silicone materials have many excellent unique properties.There are many applications in many fields and industries.Sulfone-containing polysiloxanes usually have good rigidity,temperature resistance,heat-resistant oxidation,excellent dielectric properties,creep resistance,acid,alkali,salt corrosion resistance,ion radiation resistance,non-toxicity,good insulation and self-extinguishing properties,etc.Introducing the sulfone group into the polysiloxane can obtain a sulfone containing polysiloxane that combines excellent properties of both polysiloxane and sulfone-containing polymer,that is,a modified silicone material that may exhibit new characteristics.The base rubber of silicone rubber is polysiloxane,its main chain is inorganic groups and side chain is organic groups.These unique nature gives silicone rubber better applicability in special fields than other ordinary rubbers.However,the dielectric properties of ordinary silicone rubber cannot satisfy its practical application as a dielectric elastomer in drivers,capacitors,and other devices.Sulfone groups has a larger dipole moment,it can change the dielectric properties of silicone rubber.This paper mainly uses thiol-ene reaction and sulfide oxidation reaction to design and synthesize a new type of sulfone-group polysiloxane,and uses it as the base gum to prepare room temperature vulcanized silicone rubber.The main research are as follows:1.Novel sulfone groups cyclosiloxane were designed and synthesized through thiol-ene reaction and the silicon-oxygen bond breakage and rearrangement reaction.First,using D4vi as the starting monomer,a series of thioether containing cyclic siloxanes were obtained by the thiol-ene reaction,and then sulfide oxidation was further carried out using Oxone as an oxidant to obtain a series of new sulfone-groups cyclosiloxanes.During the sulfide oxidation process,a rearrangement of the silicon-oxygen bond breakage was occurred,and the rearrangement reaction was found to be an equilibrium reaction,and sulfone-groups cyclosiloxane was obtained by adjusting the oxidation conditions.The homopolymerization and copolymerization of the new sulfone cyclosiloxane were studied,and the fluorescent and thermodynamic properties of the pendant sulfone polysiloxanes were studied and analyzed.It was found that the sulfone group weakened the polysiloxane containing sulfide bond and the fluorescent properties of alkanes,but its thermal stability was improved.In addition,new preparation methods and approaches were proposed for the synthesis of new sulfone-containing cyclicsiloxanes and polysiloxanes with side-sulfone groups.2.The thiol-ene reaction was used to synthesize the sulfide containing cyclic siloxane monomer.And then the oxidation conditions were adjusted to obtain the polysiloxanes with side-sulfone groups.The polysiloxanes with side-sulfone groups and the hydroxyl-terminated polydimethylsiloxane was used as the base gum,the methyltrimethoxysilane was used as the crosslinking agent,and the gas phase white carbon black(TS-530)was used as fillers,and dibutyltin disilicate was used as a catalyst to prepare a new type of sulfone-groups room temperature vulcanized silicone rubber.The study found that the dielectric constant and tensile strength of the new sulfone-groups room temperature vulcanized silicone rubber have been significantly improved,and the thermodynamic properties of silicone rubber have also been significantly improved.The new sulfone-groups room temperature vulcanized silicone rubber has potential application prospects in the dielectric elastomer driver,and the preparation of silicone rubber based dielectric elastomer provides a new perspective on the use of polar groups to modify base gums.