Synthesis, Characterization and Property Evaluation of Vinyl Fluorosilicone

Vinyl end and pendant fluorosilicone (VFS), containing various amounts of vinyl (Vi) and 3,3,3-trifluoropropyl (TFP), were synthesized by hydrolysis of two chlorosilanes containing vinyl and TFP respectively and polycondensation between hydrolysate and 1,3-divinyldetramethyl-disilxoane ((MMvi)-M-vi). The VFS was characterized by FTIR, F-19 NMR, Si-29 NMR, H-1 NMR and GPC. The Vi/TFP molar ratio of VFS was approximately equal to the feeding molar ratio of two silanes. Thermal stability was improved by higher molecular weight and higher Vi/TFP. The molecular weight, polydispersity index (PDI), surface tension and refractive index increased with the change of Vi/TFP from 4.82 to 9.66. Low surface tension of VFS could decrease releasing force and improve release performance of silicone release coating. TFP of VFS could avoid corrosion and unfavorable reaction in the encapsulation material of Light Emitting Diodes (LEDs) by reducing the permeation rate of moisture and oxygen.