受阻胺光稳定剂的生产与研究进展

简要介绍国内外HALS的生产状况，包括HALS的主要系列、品种、产量和需求情况。阐述了HALS的研究现状与发展趋势，指出该领域正向高相对分子质量化、多功能化、低碱化反应性方向发展。并对国内HALS产业提出一些发展建议。     

受阻胺光稳定剂的生产与研究进展

介绍了国内外受阻胺光稳定剂（HALS）的生产状况,包括HALS的主要系列、品种、产量和需求情况。阐述了HALS的研究现状与发展趋势,指出该领域正向高相对分子质量化、多功能化、低碱化反应性方向发展,并提出了国内HALS产业发展的一些建议。     

耐药型受阻胺光稳定剂的发展

介绍了耐药型受阻胺光稳定剂（HALS）的发展。针对低pKa值HALS,含缚酸剂的HALS,以及N-烷基化和N-烷氧基化HALS,详细叙述了典型品种的性能特点,并报道了耐药型受阻胺光稳定剂的最新研究成果。     

国内受阻胺类光稳定剂合成研究新进展

受阻胺类光稳定剂(HALS)具有优异的抗老化性能,其合成研究一直是抗老化领域科研工作者的研究重点。本文从商品化产品的工艺优化、新型HALS的合成研究、含烷氧基团的受阻胺结构(NOR型)HALS的烷氧基化方法三个方面论述了近十年国内HALS合成的研究情况。     

N,N''-二(2,2,6,6-四甲基-4-哌啶基)-1,6-己二胺

受阻胺类光稳定剂(HALS)已成为聚合物稳定剂消费市场的主流,其发展趋势是高分子量化,相对分子量达到2000～3000;低碱性;复合化,多功能化;反应型HALS开始使用。制约我国HALS发展的关键因素是中间体的生产技术,国内只有哌啶醇一种中间体实现了工业化。目前中间体N,N 二(2,2,6,6-四甲基-4-哌啶基)-1,6-己二胺的中试工作已完成,分离收率达90％以上,年产千吨的生产装置将于11月投产,这将会促进国内HALS的发展,以应对WTO的挑战。     

受阻胺类光稳定剂的发展

详细介绍了受阻胺类光稳定剂（HALS）的作用机理及国内外发展现状，指出应向高分子量化发展，开发低碱性HALS及反应键合型HALS。     

受阻胺光稳定剂的协同作用及研究进展

受阻胺光稳定剂（HALS）效率高、可循环、普适性强、应用广泛，是光防护领域不可或缺的1类光稳定剂。然而，单一HALS的使用往往难以达到预期效果，因此协同互配在抗老化领域的研究与应用越来越重要，是提高HALS效率的手段之一。文章介绍了HALS的化学结构与作用机理，概述HALS的应用领域与光防护效果，对HALS与紫外线吸收剂（UVA）、光屏蔽剂及抗氧剂发挥协同作用的研究进行分析，指出HALS高效化、复配技术等是未来的发展方向。     

受阻胺光稳定剂作用机制及其适用性研究综述

受阻胺光稳定剂(HALS)是一种被广泛应用在塑料行业的新型高效助剂。本文综述了HALS捕获自由基、氢过氧化物分解、猝灭单线态氧三种作用机理,以及其在聚烯烃防光老化、防热老化方面的应用,并对HALS的发展进行了展望。     

受阻胺光稳定剂的开发应用

受阻胺光稳定剂（HALS）是具有高效,多功能,新颖性和发展最快的一种高分子材料助剂,可数倍延长农膜等塑料制品的寿命,本文论述了HALS国内外开发应用概况,生产品种,光老化和HALS光稳定化机理,助剂配伍性,HALS发展趋势,简要介绍聚合型HALSSGW-944特性,合成工艺路线。     

HALS中间体三丙酮胺及其衍生物的合成技术及应用研究进展

三丙酮及其衍生物是受阻胺光稳定剂(HALS)的中间体。本文综述了三丙酮胺及其几种重要衍生物的合成技术以及进展,总结了几种重要衍生物在HALS中的应用以及HALS的发展趋势,最后指出了三丙酮胺及其衍生物在发展过程存在的问题。     

受阻胺类光稳定剂

以目前广泛使用的受阻胺类光稳定剂 (HALS)为出发点 ,论述了此类光稳定剂的结构、品种、光稳定机理、使用要求、发展趋势等。重点讨论了HALS与其他助剂的并用效果和HALS新产品开发状况。     

受阻胺光稳定剂和抗氧剂并用对聚合物紫外光稳定性的影响

阐述了受阻胺稳定剂(HALS)和抗氧剂的分类和作用机理,重点介绍了受阻胺类光稳定剂和抗氧剂并用对聚合物紫外光降解中的影响。当受阻胺类光稳定剂和抗氧剂并用时,既有协同效应,又有对抗效应,也有加和效应。这依赖于受阻胺类光稳定剂和抗氧剂的种类。同时介绍受阻胺光稳定剂发展的趋势。     

2-氯-4,6-二(2,2,6,6-四甲基-4-哌啶氧基)-1,3,5-三嗪的合成研究

新型光稳定剂是近年来发展迅速的热门课题,2-氯-4,6-二（2,2,6,6-四甲基-4-哌啶氧基）-1,3,5-三嗪的合成是开发新型哌嗪系、受阻胺类光稳定剂的重要步骤,对用碳酸氢纳、氰尿酰氯、哌啶醇合成目标产物的反应机理进行了推测,并考察了不同反应条件对收率的影响,确定了该合成的最佳反应条件.     

受阻胺类光稳定剂的研究进展

国内外对受阻胺类光稳定剂(HALS)的应用研究十分活跃,本文重点论述了HALS的结构、制备、光稳定机理、应用和发展趋势。     

New synergists for hindered amine light stabilizers

The development of hindered amine light stabilizers (HALS) in the seventies led to a tremendous increase in the outdoor use of polyolefins. Although since that time a great deal of insight has been gained into the UV-degradation mechanism of polyolefins and the mechanism of action of HALS, no new UV-stabilization chemistry has been discovered. In this paper, the most recent thoughts about the UV-degradation mechanism of polyolefins (initiation of photo-oxidation by polymer oxygen charge transfer complexes (CTCs)) and new insights into the mechanism of action of HALS stabilizers (quenching of these CTCs) are explored as a basis for designing new UV-stabilizers. A mechanism is proposed that explains the action of HALS as a quencher. Based on this mechanism several other possible quenchers (bridged amines) have been suggested. It is shown that these bridged amines are active as UV-stabilizers in films and plaques and that they show a synergism with HALS stabilizers. These new stabilizers are the most effective when they are present at concentrations higher than 0.1% and at higher concentrations of HALS. In such cases the addition of these synergists to a HALS stabilized system can lead to an improvement of a factor of 2-3.     

HALS stabilization of LDPE films used in agricultural applications

The mechanism of stabilization of low density polyethylene (LDPE) films used in agricultural applications with hindered amine light stabilizer (HALS) has been studied under the influence of natural weather for 750 d. The structural modifications in the exposed films were monitored by Fourier transform infrared spectroscopy (FTIR), while the examination of the surface behavior was performed by scanning electron microscopy (SEM). Finally, the stability of the material was evaluated by measuring the percent elongation at break. The performance of HALS in the films was analyzed through a comparative study carried out on unstabilized LDPE samples exposed to the same weathering conditions for 170 d. The FTIR results have shown that HALS reduces significantly the rate of formation of ketone groups in the exposed films due to deactivation of the excited ketonic carbonyls. This indicates the role of HALS to prevent the occurrence of Norrish I and II reactions. On the other hand, the development of vinyl groups at 909 cm^–1 during the exposure period of 750 d is attributed to the photolysis of the ester group of the HALS localized at 1 734 cm^–1 in the film and the photooxidation of the polymer. The decrease observed in the ester band suggests the loss of the stabilizer. For the unstabilized LDPE film, the results have revealed a fast increase in both ketonic and vinyl groups attributed mainly to Norrish II reactions. This resulted in chain scission responsible for both the rapid drop in elongation at break and the considerable deterioration of the surface of the exposed film. On the contrary, the presence of HALS in the film resulted in a large retention of the elongation at break. Moreover, SEM analysis reveals the role of HALS to prevent the surface damage by reducing the number and size of microcracks.     

Effect of penta- and tetramethyl HALS on the radiation resistance of polypropylene

2,2,6,6-Tetramethyl-4-piperidinyl methacrylate (TMPM), a new pentamethyl HALS 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate (PMPM), their homopolymers (PTMPM and PPMPM), and their copolymers, [i.e., TMPM or PMPM copolymerized with monomers methyl methacrylate (MMA), methacrylic acid (MAA), acrylic acid (AA), and styrene (St) separately] were synthesized. PMPM shows an extremely excellent stabilizing effectiveness on improving the radiation resistance of polypropylene (PP) in comparison with other low molecular weight (LMW) HALS or polymeric HALS. Polymeric HALS shows a much higher thermal stability and better extraction resistance than that of LMW HALS. It is found that the Eb values of the PP-added pentamethyl HALS series are higher than those of PP with the corresponding tetramethyl HALS series at a given irradiation dose. A conclusion can be drawn that the pentamethyl HALS series has a higher stabilizing effectiveness than that of the tetramethyl HALS series. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 69: 2649–2656, 1998