季戊四醇四苯甲酰甲酸酯的合成及光引发性能

大分子光引发剂可以解决小分子光引发剂残留碎片带来的毒性对其在食品和医用材料领域应用的限制,为此,本文以苯甲酰甲酸(BF)和季戊四醇(PET)为原料,通过酰氯法在季戊四醇主链上引入了4个苯甲酰甲酸酯基团,制备了多官能度的季戊四醇四苯甲酰甲酸酯(PTF)大分子光引发剂。 PTF在225 ℃时失重15%,热稳定性优于2-羟基-2-甲基-1-苯基-1-丙酮(1173)光引发剂,与1173光引发剂相比,用PTF作光引发剂所制备的光固化涂料,在起始分解温度以及失去相同比例质量所需温度均提高了100 ℃以上。 PTF引发三羟甲基丙烷三丙烯酸酯(TMPTA)聚合时最大反应速率为0.037 s^-1,最终双键转化率为39.5%,PTF光引发活性大于1173光引发剂。 在同等实验条件下,PTF的相对小分子残留量仅为1173光引发剂的5%。

Synthesis and Photoinitiation Properties of Pentaerythritol Tetrabenzoyl Formate

The limit of small molecule photoinitiators to applications of food and medical materials due to the toxicity of its residual fragments can be solved by the macromolecular photoinitiators. In this paper, pentaerythritol tetrahydrobenzoylformate(PTF) was synthesized using benzoyl formic acid(BF) and pentaerythritol(PET) as raw materials by acid chloride method. The results of thermal analysis show that there is 15% mass loss at 225 ℃ for PTF and its thermal stability is better than that of 2-hydroxy-2-methyl-1-phenyl-1-propanone(1173 photoinitiator). The initial decomposition temperature and the temperature with the same mass loss for the photocurable coatings using PTF as the photoinitiator are 100 ℃ higher than those for coatings using 1173 photoinitiator. The results show that the maximum reaction rate is 0.037 s^-1, the final double bond conversion is 39.5%, and PTF has higher photoinduced activity than 1173 in the trimethylolpropane triacrylate(TMPTA) polymerization by light-differential scanning calorimetry. The residue content of PTF is only 5% of that of 1173 photoinitiator under the same experimental conditions.