两亲性苯甲酰甲酸酯类光引发剂及其引发性能

Amphiphilic benzoylformate photoinitiator and its initiating property

以苯甲酰甲酸和三乙二醇为原料,合成了一种两亲性光引发剂苯甲酰甲酸三乙二醇单酯(TGBF),并利用UV-Vis、电子顺磁共振波谱(ESR)及实时红外光谱(RTIR)探究了TGBF的光吸收性能、光降解机理、水中溶解性以及引发光聚合的能力。结果表明,TGBF在300 nm以上波长的摩尔消光系数较低,但在405 nm LED光源照射下,能够发生分子内或分子间的夺氢反应,并产生烷基自由基引发单体聚合。TGBF具有良好的水溶性,可高效地引发油性单体三丙二醇二丙烯酸酯(TPGDA)与水性单体聚乙二醇400二丙烯酸酯[PEG(400)DA]聚合,最终双键转化率可达80%以上。TGBF具有优异的引发油性单体TPGDA与水性单体PEG(400)DA深度聚合的能力,聚合深度分别达到5.6和6.5 cm。

A water-oil amphiphilic photoinitiator,triethylene glycol benzoylformate(TGBF)was synthesized from benzoylformic acid and triethylene glycol.The light absorption properties,photodegradation mechanism,solubility in water and ability to initiate photopolymerization of TGBF were investigated by UV-Vis spectroscopy,electron spin-resonance spectroscopy(ESR)and real-time infrared spectroscopy(RTIR).The results showed that the molar extinction coefficient of TGBF was low at wavelengths above 300 nm.However,TGBF was able to undergo intramolecular or intermolecular hydrogen abstraction reaction to produce alkyl radicals to initiate polymerization of acrylate monomers under 405 nm LED light irradiation.In addition,TGBF had good water solubility,could effectively initiate polymerization of oil-based tripropylene glycol diacrylate(TPGDA)and water-based polyethylene glycol 400 diacrylate[PEG(400)DA],and the final double bond conversions reached more than 80%.More importantly,TGBF exhibited excellent ability to initiate deep polymerization of oil-based monomer TPGDA and aqueous monomer PEG(400)DA,with polymerization depths of 5.6 and 6.5 cm,respectively.