Synthesis of hydroxyl terminated fluorinated polysiloxane and properties of its modified waterborne polyurethane

Hydroxypropyl terminated fluorinated polysiloxane was synthesized via hydrosilylation,with hydrogen terminated fluorinated polysiloxane and allyl alcohol as raw materials and chloroplatinic acid as catalyst,and applied in preparing modified waterborne polyurethane. Influence of synthetic process factors on the double bond conversion was researched,the synthesis process conditions were optimized,the structure of the synthesis product was characterized by FT-IR、1H-NMR and gel permeation chromatography( GPC),and the properties of emulsion and film of modified waterborne polyurethane and coated fabric were measured. The results showed that the side reaction inhibitor could effectively inhibit the side reaction of hydrosilylation. The optimal synthesis process conditions of hydroxypropyl terminated fluorinated polysiloxane were that: the dosage of side reaction inhibitor was 0. 2 %,the dosage of the catalyst was 60 mg / L,the reaction temperature was 75 ℃,and reaction time was 4 h. The particle size of the emulsion of waterborne polyurethane was 45 nm,and the water contact angle and the water absorption of the film were 106. 8° and 28. 1% respectively. Compared with the unmodified polyurethane,the water resistance of the fabric coated with the modified waterborne polyurethane was improved significantly.