Synthesis and evaluation of fluorosilicone-modified starch for protection of historic stone

摘要

Starch is sensitive to moisture and is weak to durability in the protection application to ancient relics. Therefore, two fluorosilicone-modified starches are firstly prepared and evaluated for the protection of historic stones. The fluoro-silicone copolymer grafted starch of P(VTMS/12FMA)-g-starch is synthesized by grafting copolymer of vinyltrimethoxysilane (VTMS) and dodecafluoroheptyl methacrylate (12FMA) onto starch. While the fluoro-silicone starch latex of VTMS-starch@P(MMA/BA/3FMA) is obtained by emulsion polymerization of VTMS primarily grafted-starch (VTMS-starch) with methyl methacrylate (MMA), butyl acrylate (BA) and 2,2,2-trifluoroethyl methacrylate (3FMA). The grafting fluorosilicone copolymer onto starch improves obviously their hydrophobic and thermal properties. Comparatively, VTMS-starch@P(MMA/BA/3FMA) film performs higher water contact angle (107 degrees) and thermal stability (350-430 degrees C) than p(VTMS/12FMA)-g-starch film (72 degrees, 250-420 degrees C) due to the migration of fluorine-containing group onto the surface of film during the film formation. Therefore, VTMS-starch@P(MMA/BA/3FMA) shows much better protective performance in water-resistance, and salt/freeze-thaw resistance for stone samples. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41650.