Research On The Preparation And Properties Of Polyurethane Elastomers Modified With Polydimethylsiloxane

Polyurethane elastomers are widely used in daily life,They are a special kind of polymer materials with various raw materials and formulations.The adjustable range of properties for them is very wide.The development of traditional polyurethane elastomers can be traced back to 1940s.In the past few decades the development of polyurethane elastomers were very rapid,research on them has been relatively mature.With excellent mechanical properties and wear resistance,they are widely applied in all walks of life.However,poor surface properties,water resistance and a lack of the high and low temperature resistance limit their scope of application.Therefore,recent years polyurethane elastomers were modified to make them with other properties such as water resistance,high and low temperature resistance,better surface properties and so on attached much attention.polysiloxane-based polyurethane is one way to modify them.Mechanical properties of polydimethylsiloxane-based polyurethane using polysiloxane as soft segments is low,and their preparation is tedious and long.In this paper,by using different molecular weight hydroxyalkyl polysiloxane and polyether polyol(PPG),4,4'-two phenyl methane diisocyanate(MDI),1,4-butanediol(BDO)as raw materials,N,N-dimethylformamide(DMF),dioxane(DOX),tetrahydrofuran(THF)as solvents,stannous octoate as catalyst,the effects of reaction temperature,reaction time and solvent on the properties of modified polyurethane were investigated.On the basis of the two-step method,the polysiloxane polyurethane elastomer is successfully synthesized by optimizing the suitable solvent and synthetic process.The preparation is simple and efficient,moreover,the mechanical properties of the product are excellent,and the temperature resistance is good.In addition,polysiloxane-polyether based polyurethane elastomers were also synthesized.The preparation method is a combination of bulk polymerization and solution polymerization,polysiloxane and hydroxyl polyether were embedded in the backbone of polyurethane successfully.The transparency and gloss of the products is very good,moreover,they have excellent mechanical properties,better compatibility and heat resistance,by adjusting the content of polysiloxane,elastomers with excellent mechanical properties can be obtained..