Study on Photolysis of Polymers and Surfactants Containing Benzyl Groups

含苄基聚合物和表面活性剂的光解研究

• 批准号: 09650977
• 负责人: ITOH Yoshihiro
• 金额: $ 2.11万
• 依托单位: Shinshu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650977/
• 关键词: benzyl; photodegradative polymer; photolysis; photolysis mechanism; surfactant; ultraviolet; ベンジル基

Much attention has been paid to photodegradative polymers because of emergent disposal of waste plastics. In the present study, to explore the UV-photodegradative polymeric materials, a series of naphthylmethyl- and benzyl-xnethacrylate polymers and their monomeric model compounds were prepared and their photoreactivity was examined in solution and cast films. Introduction of alpha-methyl substituents into the model compounds decreased their photolysis efficiencies and altered the product distribution, which may be mainly due to steric hindrance around the ester bond. The ester bond cleavage in naphthylmethylmethacrylate polymers also showed substituent-dependent, but the main-chain scission scarcely occurred, in particular in cast films. In benzylmethacrylate polymers, in contrast, the ester bond cleavage was less substituent dependent, while the main-chain scission occurred efficiently, which was more effective in methacrylate polymers than in acrylate ones. Such differences in the photoreactivity reflect not only the steric hindrance of the monomer units but also the stability of radicals formed in the polymer main chain. It was also found that cationic surfactants and polyelectrolytes containing benzylammonium groups caused photoinduced decomposition of some aromatic compounds in aqueous solution. These materials would be useful for decomposition and removal of organic pollutants in waste water. Such applied studies are in progress.

由于废塑料的紧急处理，光降解聚合物受到了广泛关注。在本研究中，为了探索紫外光降解聚合物材料，制备了一系列萘甲基丙烯酸酯和苄基甲基丙烯酸酯聚合物及其单体模型化合物，并在溶液和流延膜中检查了它们的光反应性。在模型化合物中引入α-甲基取代基降低了其光解效率并改变了产物分布，这可能主要是由于酯键周围的空间位阻所致。甲基丙烯酸萘甲酯聚合物中的酯键断裂也表现出取代基依赖性，但主链断裂几乎不发生，特别是在流延膜中。相比之下，在甲基丙烯酸苄酯聚合物中，酯键断裂对取代基的依赖性较小，而主链断裂有效发生，这在甲基丙烯酸酯聚合物中比在丙烯酸酯聚合物中更有效。这种光反应性的差异不仅反映了单体单元的空间位阻，还反映了聚合物主链中形成的自由基的稳定性。研究还发现，含有苄基铵基团的阳离子表面活性剂和聚电解质会引起水溶液中某些芳香族化合物的光致分解。这些材料可用于分解和去除废水中的有机污染物。此类应用研究正在进行中。

项目成果

Yoshihiro Itoh: "Steric effect on photochemistry of benzyl ester derivatives I.Photolysis of 1-(naphthyl)ethyl alkanoates in methanol" Journal of Photochemistry and Photobiology A:Chemistry. 117・2. 91-98

Yoshihiro Itoh：“苄基酯衍生物光化学的空间效应 I. 1-(萘基)乙基链烷酸酯在甲醇中的光解”《光化学与光生物学杂志 A：化学》117・2。

Yoshihiro Itoh et.al.: ""Steric effect on photochemistry of benzyl ester derivatives 1.Photolysis of 1- (naphthyl) ethyl alkanoates in methanol"" Journal of Photochemistry and Photobiology A : Chemistry. 117-2. 91-98 (1998)

Yoshihiro Itoh 等人：“苄酯衍生物光化学的空间效应 1.1-（萘基）链烷酸乙酯在甲醇中的光解”” 光化学与光生物学杂志 A：化学。

Yoshihiro Itoh: "Steric effect on photochemistry of benzyl ester derivatives I. Phptolysis of 1- (naphthyl) ethyl alkanoates in methanol" Joumal of Photochemistry and Photobiologe A : Chemistry. 117・2. 91-98 (1998)

Yoshihiro Itoh：“苄基酯衍生物光化学的空间效应 I. 1-(萘基)链烷酸乙酯在甲醇中的裂解”Journal of Photochemistry and Photobiloge A：Chemistry 117・2 (1998)。