CHARACTERIZATION OF A DISSOCIATIVE EXCITED-STATE IN THE SOLID-STATE - PHOTOCHEMISTRY OF POLY(METHYL METHACRYLATE) - PHOTOCHEMICAL PROCESSES IN POLYMERIC SYSTEMS .5.
CHARACTERIZATION OF A DISSOCIATIVE EXCITED-STATE IN THE SOLID-STATE - PHOTOCHEMISTRY OF POLY(METHYL METHACRYLATE) - PHOTOCHEMICAL PROCESSES IN POLYMERIC SYSTEMS .5.
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DOI：
10.1021/ma60078a060
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发表时间：
1980-01-01
期刊：
影响因子：
5.5
通讯作者：
MOACANIN, J
中科院分区：
文献类型：
--
作者：
GUPTA, A;LIANG, R;MOACANIN, J
在303 K真空中测量了聚甲基丙烯酸甲酯直接激发光过程的量子产率。自由基上形成的键断裂激发后，其特征在于ESR光谱。通过GC、GC-MS和FT IR光谱对产物进行了分析。为了解释这些数据，提出了具有以下主要特征的光降解机理：（1）酯侧链以单位效率进行光解键断裂;（2）大多数链自由基通过与小自由基复合而衰变。
Quantum yields of principal photoprocesses on direct excitation of poly (methyl methacrylate) have been measured at 303 K in vacuo. Radicals formed on bond cleavage following excitation have been characterized by ESR spectroscopy. Product analyses have been carried out by GC, GC-MS, and FT IR spectroscopy. A mechanism of photodegradation with the following principal features has been proposed in order to interpret these data:(1) The ester side chain undergoes photolytic bond cleavage with unit efficiency and (2) most chain radicals decay through recombination with small radicals.