UV光催化桐油基多元醇的制备及超支化聚氨酯的表征

Preparation of Tung Oil-Based Polyol via UV Photocatalysis and Its Application on Hyperbranched Polyurethane

首先将桐油与甲醇经过酯交换反应得到桐酸甲酯,再将其与过氧化氢和乙酸反应制备环氧桐酸甲酯;然后以三芳基硫金翁盐为催化剂,在UV光条件下催化环氧桐酸甲酯与二乙醇胺开环,制备桐油基多元醇;最后以桐油基多元醇、异佛尔酮二异氰酸酯、甲基丙烯酸羟乙酯等为原料,以二月桂酸二丁基锡为催化剂,经过两步法反应制备了桐油基超支化聚氨酯丙烯酸酯。结果表明,在UV光条件下,三芳基硫金翁盐可以催化环氧桐酸甲酯开环制备桐油基多元醇,其羟基值为599.54 mg KOH/g,相对分子质量为544;以桐油基多元醇为核得到的聚氨酯丙烯酸酯具有良好的光固化活性,以及良好的热稳定性能和力学性能,并且成膜的表面光滑、平整,其玻璃化转变温度为37.2℃,拉伸强度为8.58 MPa,断裂伸长率为23.31%,表面张力为41.36 mJ/m 2。

The methyl eleostearate(ME)prepared by transesterification of tung oil with methanol was used to synthesize epoxidized methyl eleostearat(EME)by the reaction with hydrogen peroxide and acetic acid under the catalysis of concentrated phosphoric acid.Then,epoxidized methyl eleostearat was reacted with diethanolamine(DEA)to prepare tung oil-based polyols under UV irradiation using triarylsulfonium salts as catalyst.Lastly,a UV-curable tung oil-based hyperbranched urethane acrylate dispersion was prepared by a two-step procedure using tung oil-based polyol,isophorone diisocyanate(IPDI)and hydroxyethyl methacrylate(HEMA)as raw material and dibutyltin dilaurate(DBTAL)as catalyst.And the chemical structures of the products were identified by Fourier transform infrared spectroscopy(FT-IR),gel permeation chromatography(GPC),thermogravimetric analysis(TGA),dynamic mechanical analysis(DMA),physical and mechanical properties,and contact angles.The results indicate that the hydroxyl value of tung oil based polyols is 599.54 mg KOH/g and the average relative molecular weight is 544.And the tung oil based hyperbranched polyurethane acrylate(TO-based PUA)possesses good thermal stability and mechanical properties,including glass transition temperature of 37.2℃,tensile strength of 8.58 MPa,breaking elongation of 23.31%,and surface tension of 41.36 mJ/m 2.