β-二酮化合物光稳定行为的研究

研究了β-二酮类化合物二苯甲酰甲烷、苯甲酰丙酮、对苯二甲酰乙酸乙酯的光稳定行为,在β-二酮类化合物的溶液中存在着烯醇式和酮式平衡。当以紫外光进行辐照时,烯醇式异构体不断减少,酮式的含量则不断增多。由于这些化合物有不同的互变异构化过程以及不同的氢键形成能力,因此,它们对高聚物有着不同的稳定化能力。我们提出的二苯甲酰甲烷的光稳定机理,不同于Otterstedt提出的机理。新的统一的光稳定机理尚待进一步深入研究.

A study on the photostabilizing behavior of b-diketones

Photostabilizing behavior of 3 b-diketones (dibenzoylmethane, benzoylacetone, di-Et terephthaloyl acetate) was investigated. b-Diketones in solution exist in a thermal equilibrium via enol-keto tautomerism. Under UV-irradn., the absorption of enol form decreases, whereas the ketone form increases with increasing irradiation time. Due to the fact that 3 compounds have different tautomeric process and different ability of H bond formation, it could be expected that they have different ability for polymer stabilization. The result of photostabilization of dibenzoylmethane could not be explained by Otterstedt's mechanism. An alternative consideration was proposed.