1,2,2,6,6-五甲基哌啶醇光稳定作用的研究

本文研究了1,2,2,6,6-五甲基哌啶醇在异辛烷溶液中的光稳定作用。实验结果表明:五甲基哌啶醇具有和四甲基哌啶醇基本相同,而此四甲基哌啶醇氮氧自由基略优的光稳定效率;五甲基哌啶醇和四甲基哌啶醇一样,在光稳定作用过程中产生氮氧自由基,并且氮氧自由基浓度变化经历了一个最大值,但其积累的速度及达到的浓度极大值均比四甲基哌啶醇的场合为低。实验还发现,五甲基哌啶醇在光稳定过程中产生一个稳定中间产物——N-氧化-1,2,2,6,6-五甲基哌啶醇。据此,提出了五甲基哌啶醇首先转化为N-氧化物,进而转化为氮氧自由基的两步作用机理。     

哌啶类化合物和有机过氧化物体系引发甲基丙烯酸甲酯聚合的研究

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。     

TMP与受阻酚Irganox 1010在异辛烷溶液中并用时光稳定作用的研究

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。     

2,2,6,6-四甲基哌啶醇和2-羟基-4-辛氧基二苯甲酮对聚丙烯膜光稳定作用的协同效应

<正> 受阻胺(2,2,6,6-四甲基哌啶的衍生物)是近年来发展起来的一类新型高效光稳定剂,它和其它稳定剂并用时的稳定效果和作用机理,是重要的研究课题.Allen研究了Tinuvin 770(癸二酸双(2,2,6,6-四甲基哌啶)酯)和一系列抗氧剂同时添加到聚丙烯膜中时的效应,指出其中许多抗氧剂和Tin.770都有显著的反协同效应;他的研究还表明,     

新型受阻胺光稳定剂3-（2，2，6，6-四甲基哌啶4-氨基）丙酸十二酯的合成

建立了受阻胺光稳定剂3-(2,2,6,6-四甲基哌啶-4-氨基)丙酸十二酯的合成工艺.以2,2,6,6-四甲基-4-哌啶胺、丙烯酸甲酯为原料,经M ichael加成,生成的3-(2,2,6,6-四甲基哌啶-4-氨基)丙酸甲酯再与十二醇进行酯交换反应制得.并对所涉及的酯交换反应的工艺参数进行了优化.实验结果表明,四异丙基钛酸酯催化剂的催化效果最好;在3-(2,2,6,6-四甲基哌啶-4-氨基)丙酸甲酯与十二醇的摩尔比为1∶1.10,四异丙基钛酸酯催化剂的用量为反应物总质量的0.30%,反应温度180℃,反应时间8 h的条件下,酯交换反应收率为90.6%.该工艺总收率为86.3%.目标产物及中间体的结构通过MS进行了表征.     

双功能受阻胺与紫外线吸收剂并用的协同效应研究

本文用IR、UV、ESR、TLC等方法研究了新型的双功能受阻胺光稳定剂,Tinuvin-144 [2-(4′-羟基-3′,5′-二叔丁基)苄基-2-正丁基丙二酸五甲基哌啶醇酯]与紫外线吸收剂,UV-531(2-羟基-4-正辛氧基二苯甲酮)和UV-327(2-[2′-羟基-3′,5′-二叔丁基]-5-氯 代苯并三唑)并用体系对聚丙烯光稳定化的并用效应。结果表明,Tinuvin-144与UV-531,UV-327并用时均具有良好的协同效应,144对531,327或531,327对144的光分解均具有相互的保护作用。结果还表明,144与531或327无论在模拟体系或聚丙烯中,在诱导期内均不存在促使他们消耗的化学反应,提出了协同作用的机理。     

4-(甲基丙烯酸)2,2,6,6-四甲基哌啶醇酯的合成

合成4-(甲基丙烯酸)2,2,6,6-四甲基哌啶醇酯的方法,在文献上报导甚少,T.Kurosaki 用甲基丙烯酰氯和2,2,6,6-四甲基哌啶醇在苯溶液里,在三乙胺存在下进行反应制得,产率只有27%。     

乙烯系单体聚合阻聚反应(Ⅵ)——4-位取代2,2,6,6-四甲基哌啶-1氧自由基衍生物同醌类混合对MMA自由基聚合的阻聚效应

本文研究了几种4位取代2,2,6,6-四甲基哌啶-1-氧自由基及1-位取代的2,2,6,6-四甲基哌啶类化合物同醌类混合对甲基丙烯酸甲酯(MMA)自由基聚合的阻聚效应。     

负载型二乙酰氧碘苯与功能离子液体协同氧化醇为醛酮

将聚苯乙烯树脂(PS)先碘化再乙酰基化,制得了负载型二乙酰氧碘苯(PS-DIB)作为氧化剂。2,2,6,6-四甲基-N-氧自由基哌啶醇(TeMPO)与1,4-二溴丁烷反应生成4-溴丁氧基-2,2,6,6-四甲基-哌啶-1-氧化物,再与N-甲基咪唑发生季铵化反应,生成的溴化季铵盐与四氟硼酸钠进行离子交换制得氟硼酸型2,2,6,6-四甲基-N-氧自由基哌啶负载离子液体(TeMPO-IL)。室温下,以离子液体1-甲基-3-丁基咪唑四氟硼酸盐([bmim]BF4)为溶剂,PS-DIB为氧化剂,TeMPO-IL为催化剂,选择性协同氧化各种醇为相应的醛或酮。在实验条件范围内未检测到羧酸副产物。氧化剂、催化剂和溶剂均可循环使用,在苯甲醇的氧化中,循环使用5次,反应的转化率和收率均保持基本不变。     

功能离子液体催化分子氧氧化醇为醛酮

2,2,6,6-四甲基-N-氧自由基哌啶醇(2,2,6,6-tetramethyl-piperidin-4-ol-N-oxyl,TEMPO)与氯乙酰氯反应生成2-氯乙酸-2,2,6,6-四甲基-1-氧-4-哌啶醇酯,该酯与N-甲基咪唑发生季铵化反应后再与六氟磷酸钾进行离子交换制得2,2,6,6-四甲基-N-氧自由基哌啶醇负载离子液体TEMPO-IL。温和条件下以离子液体1-甲基-3-丁基咪唑六氟磷酸盐(1-butyl-3-methylimidazolium hexafluorophosphate,[bmim]PF6)为溶剂,TEMPO-IL和CuCl为催化剂,分子氧氧化各种醇为相应的醛或酮。研究发现,该氧化体系对苄醇和烯丙醇有较好的氧化效果,65℃下反应10h左右,转化率可达99%,收率可达80%~90%。氧化体系对醛酮有高度的选择性,在实验所采用的条件范围内未检测到有羧酸生成。溶剂和催化剂可循环使用,在苯甲醇的氧化中,溶剂和催化剂循环使用6次,反应转化率和苯甲醛的收率保持不变。     

双功能受阻胺光稳定剂GW-540与紫外线吸收剂并用效应的研究

本文用IR、UV、SEM等方法,研究了双功能基受阻胺光稳定剂——三(1,2,2,6,6-五甲基-4-哌啶基)亚磷酸酯(GW-540),与紫外线吸收剂UV-531、UV-327并用时对聚丙烯的防光作用,结果表明:GW-540-UV-531并用体系有良好的防光作用,呈强的协同效应;GW-540-UV-327并用体系呈弱的对抗作用。结果还表明:GW-540对531和327的光分解均有保护作用.电镜研究表明,加入GW-540后,使UV-327在聚丙烯中分散更不均匀,从而影响其效率的发挥。文中提出了两个体系的协同和对抗作用机理。     

Degradation of Benzotriazole UV Stabilizers in PAA/d-Electron Metal Ions Systems—Removal Kinetics,Products and Mechanism Evaluation

Benzotriazole UV stabilizers (BUVs) have gained popularity, due to their absorption properties in the near UV range (200–400 nm). They are used in the technology for manufacturing plastics, protective coatings, and cosmetics, to protect against the destructive influence of UV radiation. These compounds are highly resistant to biological and chemical degradation. As a result of insufficient treatment by sewage treatment plants, they accumulate in the environment and in the tissues of living organisms. BUVs have adverse effects on living organisms. This work presents the use of peracetic acid in combination with d-electron metal ions (Fe²⁺, Co²⁺), for the chemical oxidation of five UV filters from the benzotriazole group: 2-(2-hydroxy-5-methylphenyl)benzotriazole (UV-P), 2-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)-4-methylphenol (UV-326), 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)phenol (UV-327), 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328), and 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (UV-329). The oxidation procedure has been optimized based on the design of experiments (DoE) methodology. The oxidation of benzotriazoles follows first order kinetics. The oxidation products of each benzotriazole were investigated, and the oxidation mechanisms of the tested compounds were proposed.     

苯乙烯-甲基丙烯酸四甲基哌啶醇酯共聚物(PDS)与紫外吸收剂并用对聚丙烯光防护行为研究

本文采用IR、UV、SEM等实验方法,研究了高分子受阻胺PDS与紫外吸收剂UV-531(2-羟基-4-正辛氧基二苯甲酮)和UV-327(2-(2′-羟基-3′,5′,-二叔丁基)-5氯代苯并三唑)并用对聚丙烯薄膜的光防护作用。实验表明,PDS与UV-531并用有较好的协同效应。这种协同效应被证明主要是PDS对:UV-531的光氧分解有抑制作用所致。PDS与UV-327并用有弱的反协同作用。这种作用被证实是PDS在聚丙烯中的分相作用导致UV-327分散不均所致。实验还发现,PDS对UV-327的光氧分解同样具有抑制作用。并提出了在二种体系中协同与反协同的作用机理。     

苯乙烯-甲基丙烯酸四甲基哌啶醇酯共聚物(PDS)与紫外吸收剂并用对聚丙烯光防护行为研究

本文采用IR、UV、SEM等实验方法，研究了高分子受阻胺PDS与紫外吸收剂UV－531（2－羟基－4－正辛氧基二苯甲酮）和UV－327（2－（2′-羟基－3′，5′，－二叔丁基）－5氯代苯并三唑）并用对聚 烯薄膜的光防护作用，实验表明，PDS与UV－531并用有较好的协同效应，这种协同效应被证明主要是PDS对UV－531的光氧分解有抑制作用所致。PDS与UV－327并用有弱的反协同作用。这种作用被证实是PDS在聚丙烯中的分相作用导致UV－327分散不均所致，实验还发现，PDS对UV－327的光氧分解同样具有抑制作用。并提出了在二种体系中协同与反协同的作用机理。     

1,2,2,6,6-五甲基哌啶醇对聚丙烯光稳定作用的研究

<正> 关于受阻胺类光稳定剂的稳定作用机理,是近年来光稳定研究领域中广泛探讨的课题,我们用异辛烷溶液研究了1,2,2,6,6-五甲基哌啶醇的光稳定作用,结果已在前文报道,本工作是上述研究的继续,主要研究五甲基哌啶醇对聚丙烯膜的光稳定作用。     

LIGHT ACTIVATION OF A COMPLEX MIXTURE: EFFECTS OF UV EXCISION REPAIR ON THE MODULATION OF GENOTOXIC AND MOLECULAR EVENTS IN CHINESE HAMSTER CELLS

Abstract— An aqueous effluent produced during the retorting of oil shale has been shown to induce a significant genotoxic response in cultured Chinese hamster (CHO) cells following activation by near ultraviolet light (UVA). In this report the light-activated responses induced by this complex mixture were compared between two DNA excision repair deficient mutants and their parental strain, CHO-AA8-4. The mutants, UV-5 and UV-135, were hypersensitive to both the cytotoxic and mutagenic effects of concurrent exposures to the retort process water and UVA. Repair proficiency appeared to render AA8-4 relatively insensitive to low doses of UVA treatment, whereas in the two mutants a linear dose-response in the induction of 6-thioguanine resistant (6TG^®) mutations was observed even at the lower UVA doses examined. Filter DNA alkaline elution methods were utilized to demonstrate that both single-strand breaks and DNA-DNA interstrand crosslinks were induced in CHO DNA following process water and UVA treatment. Results were also obtained which indicated that the inability to repair DNA-DNA crosslinks contributed significantly to the hypersensitive response seen in the excision repair mutants following the photoactivation of this complex mixture.     

UVB-INDUCED SUPPRESSION OF THE MIXED EPIDERMAL CELL LYMPHOCYTE REACTION IS CRITICALLY DEPENDENT ON IRRADIANCE

The mixed epidermal cell lymphocyte reaction (MECLR) is a commonly used method to study the effects of ultraviolet B (UVB) radiation on the skin immune system. In UVB experiments dosimetry is very important. The influence of irradiance on the MECLR was studied in vitro using Philips FS40 lamps with variable UV intensities. Irradiation of isolated epidermal cells with high irradiance impaired the alloactivating capacity more than irradiation with low irradiance. In vivo, the influence of long-term UVB exposure on the MECLR was studied by treating normal healthy volunteers with suberythemagenic doses of UVB thrice weekly during 4 weeks. The first set of experiments, using low irradiance Sylvania UV-21 F75/85 W lamps, resulted in a decrease of MECLR responses of 83.1%. In the second set of experiments performed a year later, employing an identical protocol except for the use of high irradiance Waldmann UV-21 F85/100 W lamps, an increase of MECLR responses of 99.7% was observed. Volunteers of both sets of experiments received equal doses of UVB. In conclusion, this study shows that in vitro UVB-induced suppression of the MECLR is critically dependent on irradiance and therefore might explain contradictory results described in the literature. The in vivo data suggest that, comparable to the in vitro experiments, irradiance may influence the effects of UVB irradiation in vivo. Further experiments should prove whether this is indeed the case.     

超声萃取-高效液相色谱法同时测定人造革中7种苯并三唑类紫外线吸收剂含量

建立了超声萃取-高效液相色谱法(HPLC)同时测定人造革中7种苯并三唑类紫外线吸收剂UV-P、UV-326、UV-327、UV-329、UV-350、UV-320和UV-328含量的方法。该方法以甲醇为萃取溶剂,超声萃取人造革中的苯并三唑类紫外线吸收剂,萃取液经处理后直接进行HPLC分析,外标法定量。在信噪比(S/N)=3的条件下,UV-P、UV-326、UV-327、UV-329、UV-350的检出限均为0.05mg/kg,UV-320、UV-328的检出限均为0.10 mg/kg。在3个不同加标浓度水平下,各组分的平均加标回收率为88.19%~98.32%,相对标准偏差(RSD)为0.61%~3.74%。该方法简便快捷、灵敏度高,可用于人造革中苯并三唑类紫外线吸收剂的测定。采用该方法对市售人造革样品进行测定,结果在6个样品中检出了不同浓度水平的UV-P和UV-329。