共查询到19条相似文献,搜索用时 968 毫秒
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众所周知,受阻胺光稳定剂对聚烯烃有良好的光稳定效率,已引起世界的注意。然而,小分子量的受阻胺易于挥发,从而影响它的效率发挥[1,2],为了克服这个缺点,使小分子受阻胺的高分子化是近年来受阻胺光稳定剂发展的方向,本文主要是研究三种商品化高分子受阻胺光稳定剂对聚丙烯的稳定化作用及其效率和机理。 相似文献
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聚合物光老化、光稳定机理与光稳定剂(下) 总被引:6,自引:0,他引:6
大多数聚合物材料,包括塑料、橡胶、纤维、涂料等,在户外使用时会发生光老化而使使用寿命缩短。为有效防止聚合物材料的光劣化,人们已对聚合物的光老化和光稳定机理进行了广泛的研究并先后研发出了几个类型的光稳定剂。但由于户外应用范围不断扩大和环境不断恶化正使聚合物的光老化变得越来越复杂而光防护难度也日益加大,因此国内外有关聚合物光老化、光稳定机理的研究和光稳定剂的研发一直十分活跃。本文下篇阐述光稳定剂的作用机理并综述光稳定剂的研发进展。 相似文献
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聚合物涂层光稳定化研究进展 总被引:8,自引:0,他引:8
用于改造各种材料的表面性质并防止其光老化的聚合物涂层的光稳定化技术近年来已经成为高分子材料科学和光化学领域的又一研究热点。本文以紫外光固化聚合物涂层为重点综述了该研究领域的发展过程、理论研究特点和应用技术的生长点,并对聚合物涂层光稳定化技术的最新进展进行了评述,讨论了聚合物涂层光稳定化技术中新型光固化树脂,多功能单体、光引发剂和光稳定剂(包括紫外吸收剂和受阻胺类稳定剂)的特点及作用机理。 相似文献
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聚合物光老化、光稳定机理与光稳定剂(上) 总被引:6,自引:0,他引:6
大多数聚合物材料,包括塑料、橡胶、纤维、涂料等,在户外使用时会发生光老化而使使用寿命缩短。为有效防止聚合物材料的光劣化,人们已对聚合物的光老化和光稳定机理进行了广泛的研究并先后研发出了几个类型的光稳定剂。但由于户外应用范围不断扩大和环境不断恶化正使聚合物的光老化变得越来越复杂而光防护难度也日益加大,因此国内外有关聚合物光老化、光稳定机理的研究和光稳定剂的研发一直十分活跃。本文上篇主要阐述聚合物的光老化机理。 相似文献
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Daryl K. C. Hodgeman 《Journal of polymer science. Part A, Polymer chemistry》1980,18(2):533-539
ESR studies of the formation of stable nitroxyl radicals in the photooxidation of polypropylene containing 2,2,6,6-tetramethyl-4-hydroxypiperidine (II) and the commercial light stabilizer bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate (III) are described. Spectra of the stable nitroxyl radicals in solid polymer and in solution after extraction from the polymer were obtained. The extract from photooxidized polypropylene containing the bifunctional stabilizer (III) showed only the mononitroxyl radical. The possible formation of polymer-bonded nitroxyl radicals from (III) is discussed. 相似文献
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Dispersion polymerization of acrylamide at 40 degrees C in t-butyl alcohol-water media of varying composition (50 to 90 vol% alcohol) using a partial isopropyl ester of poly(vinyl methyl ether-alt-maleic anhydride) as the stabilizer has been studied. The isopropyl ester derivative proves to be a better stabilizer than its precursor polymer. However, the particles were polydisperse in size. The number average diameter of the particles increases linearly with the solubility parameter of the dispersion medium. Dispersions of nanoparticles of polyacrylamide are produced when the t-butyl alcohol content of the dispersion medium is 90% by volume. Comparison of the particle diameter measured by transmission electron microscopy with that measured by dynamic light scattering in acetone reveals a thickness of the hairy stabilizer layer on the dispersion particles of 31 nm. 相似文献
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对聚合物表面进行接枝聚合是一种有效的材料改性方法。近年来,S.Tazuke,Y.Ogiwara,高志民等人做了一些用紫外光引发接枝方面的工作,获得了较满意的结果。为提高聚丙烯(简称为PP)膜的光稳定性,我们研究了将一种受阻胺类光稳定剂,甲基丙烯酸2,2,6,6-四甲基哌啶醇酯(简称为MTMP)光接枝到PP膜表面的聚合过程。 相似文献
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The photostabilizing efficiencies of various light stabilizer systems in recycled pigmented polypropylene crate materials, previously in use for 6–7 years, have been examined using the standard carbonyl index and time to embrittlement methods. Thirty-two polymer film samples with and without additional stabilizer have been prepared and exposed in both a Xenotest-150 and Microscal apparatus. The performance of the various light stabilizer systems in both exposure units are compared and discussed. 相似文献
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Taguchi Y Ohtani H Tsuge S Ishida Y Kimura K Yoshikawa T 《Journal of chromatography. A》2003,993(1-2):137-142
Highly sensitive and specific determination of trace amounts of a polymeric hindered amine light stabilizer (HALS) in polypropylene (PP) materials could be established by improving reactive thermal desorption-gas chromatography (RTD-GC) in the presence of an organic alkali, tetramethylammonium hydroxide. By using nitrogen-phosphorus detection, highly selective detection of the HALS-related components was attained. In addition, the use of a polar poly(ethylene glycol) separation column alleviated the adsorption of minor specific pyrolysis products. This modified RTD-GC method allowed the determination of the polymeric HALS (Mr 1900) in PP even for trace concentrations between 100 and 500 ppm, through observing selectively the characteristic products containing a tetramethylpiperidine moiety, which had been impossible to detect under the previous RTD-GC conditions using a non-polar separation column and conventional flame ionization detection. 相似文献
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高分子受阻胺光稳定剂存在下聚丁二烯的单线态氧氧化 总被引:1,自引:0,他引:1
用粘度法、ESR、IR、GPC等方法研究了三种商品高分子受阻胺存在下聚丁二烯的单线态氧氧化,结果表明,高分子受阻胺抑止聚丁二烯的单线态氧氧化,其效率是944>PDS>770>622。用Monroe方法测定了受阻胺对单线态氧的猝灭速率常数,K_q~(-O_2),它们是944(3.2×10~6M~(-1)s~(-1)),PDS(8.2×10~5M~(-1)s~(-1)),622,770为2×10~5M~(-1)s~(-1),ESR研究表明,在本实验条件下,944和PDS能够产生稳定的氮氧自由基No,而622则不产生。用GPC研究还发现,在本实验条件下,PDS具有对聚丁二烯的接枝——交联效应,提出了这种接枝交联效应的机理。 相似文献
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Loss of light stabilizers. related to 2-hydroxybenzophenone and 2-(2-hydroxyphenyl) benzotriazole. from isotactic polypropylene was measured over the range 60–120° and during storage at 25'. The light stabilizer content in polypropylene corresponded to that used in practice. The rate constants and the activation energy were calculated from the rate of loss. The influence of the structure of stabilizer on the rate of loss from polymer is discussed. The losses of stabilizers from polymer were compared with the vapour pressure of stabilizers and with the losses of stabilizers alone at 280. The rate of diffusion of stabilizers to the surface of polypropylene and the rate of even evaporation may cause a rapid diminution of stabilizer or undesirable accumulation on the polymer surface. 相似文献
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N. S. Allen J. F. McKellard D. G. M. Wood 《Journal of polymer science. Part A, Polymer chemistry》1975,13(10):2319-2325
The photoactivity of titania pigments at different loadings in both polyethylene and polypropylene is examined by phosphorescence and carbonyl formation and a correlation between the two observed. A nickel (II) chelate stabilizer proved more effective than a hydroxybenzophenone stabilizer in the presence of anatase. This difference in stabilizing efficiency appears to be due to more efficient quenching of the excited state of the anatase by the nickel chelate than by the hydroxybenzophenone. 相似文献