Preparation of a variety of fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomer/silica nanocomposites possessing no weight loss characteristic at 800℃

摘要

A variety of fluoroalkyl end-capped N-(1,1-dimethyl-3-oxobutyl)acrylamide oligomer [R{sub}F-(DOBAA){sub}n-R{sub}F]/silica nanocomposites, in which the oligomer contents are 18-96%, were prepared by reactions of the corresponding fluorinated oligomer with tetraethoxysilane and silica nanoparticles under alkaline conditions. Each fluorinated oligomer/silica composite thus obtained is nanometer sizecontrolled very fine particles (22-68 nm) possessing a good dispersibility and stability in a variety of solvents including water. Interestingly, the weight loss of R{sub}F-(DOBAA){sub}n-R{sub}F/silica nanocomposites, in which the oligomer contents are 18-72%, were not observed at all even at 800℃, as well as the original silica nanoparticles, although the corresponding sub-micrometer size-controlled R{sub}F-(DOBAA){sub}n-R{sub}F/silica composites (particle size: 359 nm) decomposed completely at 800℃ to afford the weight loss in proportion to the content of R{sub}F-(DOBAA){sub}n-R{sub}F oligomer in composites. On the other hand, a slight weight loss of R{sub}F-(DOBAA) {sub}n-R{sub}F/silica nanocomposites, in which the oligomer contents are 75-94%, was observed at 800℃ compared to that of the original silica nanoparticles.