受阻胺光稳定剂在^(60)Coγ射线辐照下直接生成氮氧自由基的研究  

Nitroxyl free radicals formed from hindered amine light stabilizers under ^(60)Co γ-ray irradiation

作　　者：汪辉亮[1] 陈文琇[1] 

机构地区：[1]北京师范大学化学学院,北京100875

出　　处：《辐射研究与辐射工艺学报》2006年第3期145-150,共6页Journal of Radiation Research and Radiation Processing

摘　　要：利用电子自旋共振分析(Electronspinresonance,ESR)研究了几种小分子型和高分子型受阻胺光稳定剂(Hinderedaminelightstabilizer,HALS)在60Coγ射线辐照下生成氮氧自由基的规律。在空气中辐照时,几种受阻胺光稳定剂均能产生氮氧自由基。对大多数HALS,在0—10kGy的剂量范围内,氮氧自由基浓度随剂量几乎呈线性快速增加,在剂量大于10kGy以后,氮氧自由基浓度基本保持不变或随剂量呈缓慢增加的趋势。小分子型受阻胺产生的氮氧自由基浓度一般比高分子型受阻胺产生的氮氧自由基浓度高。四甲基受阻胺比五甲基光稳定剂更容易生成氮氧自由基。在氧气中产生的氮氧自由基的浓度为在空气中产生的氮氧自由基的浓度的2倍左右。还讨论了HALS在γ射线辐照下生成氮氧自由基的机理。Nitroxyl free radicals formed from several low molecular weight （LMW） hindered amine light stabilizers （HALS） under ^60Co γ-ray irradiation was studied with electron spin resonance （ESR） spectroscopy. All the HALSs irradiated in air formed nitroxyl free radicals under irradiation in air. For most of the HALSs, concentration of the nitroxyl free radicals increased linearly and quickly with absorbed dose in 0-10kGy range, but increased slowly, or even kept constant, with doses of greater than 10kGy. Concentration of nitroxyl free radicals formed from LMW HALS was usually higher than high molecular weight HALS. Tetramethyl HALS was easier to form nitroxyl free radicals than pentamethyl HLAS. Concentration of nitroxyl free radicals formed from the samples irradiated in oxygen was about two times higher than that the samples irradiated in air. Mechanisms of the nitroxyl free radical formation from the γ-ray irradiated HALSs were was discussed.

关 键 词：受阻胺光稳定剂 Γ射线辐照 氮氧自由基 

分 类 号：O631.33[理学—高分子化学] O631.34[理学—化学]