Synthesis and characterization of ureido-containing MQ silicone resin |
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Authors: | Jianjun Chen Yanping Li Xuejun Lai |
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Affiliation: | School of Materials Science and Engineering, South China University of Technology, Guangzhou, China |
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Abstract: | AbstractUreido-containing MQ silicone resin (U-MTQ) was synthesized by the hydrolysis and co-condensation reaction of ethyl silicate, ureido silane, hexamethyldisiloxane, and divinyltetramethyldisiloxane under the catalysis of hydrochloric acid. U-MTQ was characterized by FT-IR, 1H-NMR, 29Si-NMR, GPC and TGA. The influences of M/Q molar ratio and hydrochloric acid content on the yield and structure of U-MTQ were investigated. The results showed that the M/Q molar ratio of the product calculated from the 29Si-NMR spectrum was much smaller than that in the feed. As M/Q molar ratio in the feed increased, the molecular weight and its distribution index of U-MTQ decreased, and Si-OH content of U-MTQ also decreased, while the structural regularity of U-MTQ was enhanced. With HCl content increasing, the molecular weight and its distribution index of U-MTQ decreased, but the Si–OH content and structural regularity increased. Meanwhile, the yield first increased and then decreased, and reached the highest value of 71.9% when HCl content was 2.10%. Compared with MQ, the onset weight loss temperature of U-MTQ decreased from 237?°C to 158?°C, and the residue at 900?°C increased from 3.5% to 29.5%. |
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Keywords: | MQ silicone resin ureido synthesis characterization sol-gel method |
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