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<正> 最近的研究发现,五甲基哌啶醇与四甲基哌啶醇的光稳定机理有一定的不同。我们还观察到2,2,6,6-四甲基哌啶醇与2-羟基-4-辛氧基二苯甲酮(UV-531)同时添加到聚丙烯膜中具有明显的协同效应。本实验探讨了1,2,2,6,6-五甲基哌啶醇(PMP)与几种紫外吸收剂及猝灭剂的并用效应,并比较四甲基哌啶醇及五甲基哌啶醇与紫外吸收剂并用效应的差别。 相似文献
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本文用抗张强度、ESR、IR、氧吸收测定方法,以及亚甲基蓝敏化光氧化方法研究了新型受阻胺光稳定剂——三(1,2,2,6,6-五甲基-4-哌啶)亚磷酸酯(GW-540)的作用机理。实验结果表明,GW-540具有较好的光稳定效能,它能在光稳定作用过程中产生稳定的氮氧自由基(>NO·),也能分解大分子氢过氧化物及猝灭单线态氧。它的光稳定作用可能与其同时具有分解氢过氧化物,清除游离基,猝灭单线态氧等多功能的自协同作用有关。 相似文献
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本文研究了2,2,6,6-四甲基哌啶醇(简称TMP)和2,2,6,6-四甲基哌啶醇氮氧自由基(简称TMPO·)分别与四[3-(3,5-二叔丁基-4-羟基苯基)丙酸]季戊四醇酯(简称Irganox 1010)在异辛烷溶液中并用时的光稳定作用。结果表明:TMP与Irganox 1010的并用体系有反协同作用:Irganox 1010对异辛烷溶液的光氧化有敏化作用;TMP与Irganox 1010并用时,TMPO·的累积速率变慢,浓度极大值比只含TMP的样品低;TMPO·与Irganox 1010并用时,TMPO·的衰减比只含TMPO·的样品快得多。根据实验事实提出:TMPO·与Irganox 1010之间起了某种反应,该反应引起的氮氧自由基浓度的降低可能是受阻胺与受阻酚并用时产生反协同效应的主要原因。 相似文献
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本文研究了四种哌啶类环状脂肪胺哌啶(P)、2,2,6,6-四甲基-4-哌啶醇(TMP)、N-乙基哌啶(NEP)、1,2,2,6,6-五甲基-4-哌啶醇(PMP)分别与有机过氧化物过氧化苯甲酰(BPO)、过氧化月桂酰(LPO)、叔丁基过氧化氢(TBH)、过氧化笨甲酸叔丁酯(TBPB)组成的引发体系对甲基丙烯酸甲酯(MMA)聚合的影响。测定了聚合反应的表观活化能和动力学方程。 相似文献
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将4-羟基-2,2,6,6-四甲基哌啶氮氧自由基用于标记9-羧基-吖啶,得到自旋标记荧光探针4-(9-吖啶酯)-2,2,6,6-四甲基哌啶氮氧自由基. 以谷胱甘肽作为蛋白质肽模型,研究了活性氧过氧亚硝酸诱导其损伤产生的硫中心自由基的荧光表征. 自旋标记荧光探针为弱荧光物质,当与硫中心自由基作用后,导致其荧光增强,从而可对硫中心自由基进行表征. 相似文献
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The polymerization of methyl methacrylate(MMA) initiated with piperidine derivatives,such as,piperidine(P),2,2,6,6-tetramethyl-4-hydroxyl piperidine(TMP),N-ethyl iperidine(NEP),1,2,2,6,6-pentamethyl-4-hydroxyl piperidine(PMP),and organic peroxides,such as,benzoyl peroxide(BPO),lauryl peroxide(LPO),f-butyl hydroperoxide (TBH),t-butyl peroxybenzoate(TBPB) systems was studied and discussed in this paper.The polymerization rate equation and the activation energy of polymerization were determined respectively. 相似文献
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A new photostabilizer--2,2,6,6-tetramethyl-4-piperidinylsalicylate (TMPS) has been syn-thesized by ester-exchange reaction between 2,2, 6, 6-tetramethyl-4-piperidinol and methylsalicylate.The photostabilizing effect of TMPS and Tinuvin 770, PDS on the photodegradation of cis-1,4-polybutadiene has been investigated for comparison. The results observed show that the mosteffective stabilizer of the three is TMPS. The reason of the good photostabilizing effect of TMPSwas discussed by fluorescence spectra. 相似文献
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Photolysis of 2,2,4,6-tetramethyl- (1) and 1,2,2,4,6-pentamethyl-1,2-dihydroquinoline (2) in methanolic alkali yields only 4-methoxy-2,2,4,6-tetramethyl-1,2,3,4-tetrahydroquinoline in the former case and a mixture of 4-methoxy- and 4-hydroxy-1,2,2,4,6-pentamethyl-1,2,3,4-tetrahydroquinoline in the latter case. This result was rationalized by the existence of two resonance structures of an intermediate cation, viz., carbocationic and ortho-quinomethaneiminium species. The cation from 1 reacts with an alkali in the ortho-quinomethaneiminium form, and the cation generated from 2 reacts in the carbocationic form. 相似文献
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Abstract Hindered-amine light stabilizers (HALS) were surface anchored to polyolefin films by reacting the HALS, namely, 1,2,2,6,6-pentamethyl-4-piperidinol and 1,2,2,6,6-pentamethyl-4-aminopiperidine, with succinic anhydride functionalized polyolefin surfaces. The photostability of polyolefin films with surface-anchored HALS were compared with films stabilized with commercial HALS (Tinuvin 770) by melt blending. It is shown that the photostabilizing efficiency of surface-anchored HALS is superior that of melt-blended polyolefins. 相似文献
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Rainer Bachmann Clemens Burda Fabian Gerson Markus Scholz Hans-Jürgen Hansen 《Helvetica chimica acta》1994,77(5):1458-1465
Proton-hyperfine data are reported for the radical anions generated from azulene ( 1 ) and its alkyl derivatives 2 – 11 in 1,2-dimethoxyethane both ‘chemically’ with K and electrolytically. The alkyl derivatives are 1,3-dimethyl- ( 2 ), 5,7-dimethyl- ( 3 ), 1,3,5,7-tetramethyl- ( 4 ), 2-methyl- ( 5 ), 4,6,8-trimethyl- ( 6 ), 2,4,6,8-tetramethyl-( 7 ), 1,3,4,6,8-pentamethyl- ( 8 ), 1,3,4,8-tetramethyl-6-propyl- ( 9 ), 6-(tert-butyl)-1,3,4,8-tetramethyl- ( 10 ), and 1,2,3,4,6,8-hexamethylazulene ( 11 ). Alkyl substituents at the odd-numbered centers μ = 1, 3, 5, and 7 partly shift the π-spin population from the seven- to the five-membered ring, whereas those at the even-numbered centers μ = 4, 6, and 8 exert an opposite effect on the π-spin distribution. 相似文献