信息与动态

BASF推出光稳定剂新品据“Plastics Engineering”,2005,61(1):24报道,德国BASF(巴斯夫)公司Uvinul系列光稳定剂又新增3个牌号,包括1个苯并三唑类UV吸收剂Uvinul 3044和2个受阻胺光稳定剂(HALS)Uvi-nul 5062H和Uvinul 4092H。Uvinul 3044对PET、尼龙和聚碳酸酯光稳定化十分有效     

P(MMA-BA-BPMA)的合成及其改性聚甲醛光稳定性的研究

以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、2-羟基-4-(3-甲基丙烯酸酯基-2-羟基丙氧基)二苯甲酮(BPMA)为原料,采用乳液聚合的方法合成了具有光稳定官能团的丙烯酸酯类弹性体P(MMA-BA-BPMA),通过与聚甲醛(POM)熔融共混后进行紫外光老化试验,并对老化前后试样的力学性能进行了测试。结果表明:P(MMA-BA-BPMA)与聚甲醛有较好的相容性,可以通过熔融共混法均匀分散到聚甲醛中。作为一种弹性体,P(MMA-BA-BPMA)对聚甲醛有一定的增韧作用,同时由于其自身带有的光稳定化官能团,还能显著提高经紫外光老化后聚甲醛的抗冲击韧性和断裂伸长率。与直接加入弹性体和小分子光稳定剂相比,P(MMA-BA-BPMA)对聚甲醛具有更优的光稳定化效果。     

中国塑料助剂工业现状(二)

四、光稳定剂光稳定剂属耐候性助剂,多用于户外制品。能够通过屏蔽或吸收紫外线、猝灭激发态能量和捕获自由基等方式抑制聚合物的光氧化降解反应,赋予制品良好的光稳定效果。按照稳定机理和组成结构的差别,光稳定剂一般分为光屏蔽剂、紫外线吸收剂、镍猝灭剂和受阻胺光稳定剂(HALS)等四种基本类型,市售品种多为二苯甲酮、苯并三唑、镍猝灭剂和HALS。     

聚甲醛的稳定化研究进展

综述了聚甲醛（POM）的稳定化技术及其改性剂的情况。抗氧剂、紫外线吸收剂、HALS、光屏蔽剂和聚合物改性剂可用POM的稳定化。结果表明配合使用该类添加剂可明显地改善POM的稳定性。     

受阻胺光稳定剂与紫外吸收剂协同改进ABS树脂抗光氧老化性能研究

对比研究了不同类型的紫外光吸收剂(UVA)与受阻胺光稳定剂(HALS)光稳定剂协同改善ABS树脂抗光氧老化性能的效果。评价了ABS树脂样品在自然光老化条件下,黄色指数、聚丁二烯(PB)橡胶相1,4反式结构中C-H的IR吸收指数和光氧化产生的C=O的IR吸收指数、洛氏硬度及光泽度随时间变化情况。结果表明,HALS光稳定剂与草酰胺类UVA表现出较理想的协同作用,可以使ABS树脂在自然光老化6个月后黄色指数保持稳定不变。     

聚甲醛的耐候改性及其光稳定性研究

以受阻胺光稳定剂和紫外线吸收剂对聚甲醛(POM)进行光稳定化耐候改性,并对制得的耐候POM的力学性能和人工加速老化行为进行了测试和评价。结果表明,经氙灯人工加速老化1000h后,试样的拉伸强度保持率、断裂伸长率保持率和缺口冲击强度保持率分别达到103%、76.2%和84.4%,色差由7.6减小至0.8,远优于未经光稳定化处理的POM的相应性能。     

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。     

受阻胺光稳定剂及其开发研究进展

受阻胺光稳定剂(HALS)是八十年代聚合物稳定化助剂研究领域的热门课题。文章系统综述了HALS光稳定活性的发现、品种开发与应用研究方面的最新进展。     

苯并三唑/纳米TiO_2改性PPS纤维的制备及性能

为了改善聚苯硫醚(PPS)纤维的光稳定性能,将苯并三唑与纳米二氧化钛(Ti O2)按一定比例复配与PPS切片进行共混熔融纺丝,制得改性PPS纤维,研究了改性PPS纤维的可纺性及其性能。结果表明:苯并三唑/纳米Ti O2复配物的质量分数大于1.5%时,改性PPS纤维的可纺性变差;当复配物质量分数小于等于1.5%时,改性PPS纤维的表观形貌和可纺性满足工业生产要求;随着苯并三唑/纳米Ti O2的添加量增加,改性PPS纤维的断裂强度有所降低,断裂伸长率和热性能变化不大;当苯并三唑质量分数为1.5%,Ti O2为0时,PPS的结晶速率最大,改性PPS纤维的光稳定性能最好,光照前后的色度变化值为14.02。     

LED封装用透明环氧树脂的改性

选用不同种类的光稳定剂对发光二极管(LED)封装用透明环氧树脂进行改性,研究了光稳定剂对环氧树脂透光率和耐紫外线老化性能的影响。所选用的光稳定剂与环氧树脂都具有良好的相容性.采用苯并三唑类光稳定剂UV-329改性环氧树脂和受阻胺类光稳定剂HS-508改性环氧树脂封装的LED比采用普通环氧树脂EP-400封装的LED寿命分别提高59%和73%。HS-508与UV-329共同使用具有协同作用,采用最优条件改性环氧树脂封装的LED的寿命比用EP-400封装的LED提高了170%。     

各类稳定剂对聚乙烯薄膜光氧老化的稳定作用

研究了不同光稳定剂和抗氧剂及其配合使用、光稳定剂含量对聚乙烯薄膜耐光氧老化性的影响。结果表明：在各类光稳定剂中、受阻胺类稳定剂的效果最好;紫外线吸收剂与受阻胺配合使用可使膜的耐老化性有所提高;各类抗氧剂对聚乙烯膜的耐光氧老化性没有不利影响;光稳定剂含量增加,薄膜耐老化寿命提高。     

Synergistic effect of hindered amine light stabilizers/ultraviolet absorbers on the plasticized PVC during photo-irradiation

Two kinds of piperidine derivatives including a low-molecular weight (Wt. 481, T770) and a high-molecular weight (Wt. 2000–3100, C944) hindered amine light stabilizers (HALS) are added singly or with ultraviolet absorbers (UVA) in combination to plasticized poly(vinyl chloride) (PVC) samples. Digital photos, color changes, attenuated total refection-Fourier transform infrared spectra (ATR-FTIR), and mechanical properties are obtained to investigate the photostable effect of the light stabilizers on the plasticized PVC after artificial aging. PVC samples with HALS perform well at the first 400 h of irradiation in color change, FTIR, and mechanical properties, but at the last 400 h the photostability decreases. Besides, C944 performs better than T770, because C944 is a high-molecular weight UV stabilizer and has good extraction resistance. Plasticized PVC samples with UVA resist discoloring and photooxidation from the photo-irradiation. Excellent synergism is observed between the combination of HALS and UVA. PVC with HALS/UVA performs better than PVC with HALS and PVC with UVA in color differences, FTIR, and mechanical properties. The synergism is due to the different stages of functions between HALS and UVA. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Hindered amine light stabilizers in pigmented coatings

It is common practice to combine hindered amine light stabilizers (HALS) with UV absorbers (UVA) for optimal protection of coatings and plastics. The ratio of UVA and HALS strongly depends on the concentration of pigments (acting as UVA) used in the paint; that is, a clearcoatings require higher amounts of UVA, whereas opaque pigmented coatings require higher amounts of HALS. Here, especially basic HALS types can interfere with paint components like, for example, pigments due to acid/base interactions. In this article, we want to discuss the influence of HALS basicity on long-term performance in opaque white pigmented solventborne (SB) and waterborne (WB) coatings for industrial applications in correlation to the quality of the used TiO₂.     

New approaches in wood coating stabilization

A major drawback in the use of wood materials for construction and decorative applications is its sensitivity to light. Numerous researchers have shown that the ultraviolet (UV) as well as fractions of the visible (VIS) spectrum of solar radiation cause most of the chemical modification and mechanical breakdown of exposed wood. To insure the long life of wood substrates, they are usually coated with various decorative and protective finishes. The protection effect depends strongly on the opacity, i.e., the degree of pigmentation of the coatings. However, the use of UV absorbers (UVA) and hindered amine light stabilizers (HALS) both in the coating system and also in a direct wood impregnation step can improve the light stability considerably. Here the knowledge of the light sensitivity of wood is crucial for an optimal photoprotection concept for coatings and the wood substrate. This paper highlights findings of a systematic investigation of the light sensitivity of pine wood (Pinus radiata). Furthermore, it describes the correlation between quantity and type of organic UVA and HALS as well as the lignin stabilizer concept and the degree of pigmentation of the coating. These findings are of great importance for an efficient and economic use of light stabilizers in film-forming wood coating systems for pale wood species and allow a cost-effective stabilization. Presented at the 5th International Woodcoatings Congress: Enhancing Service Life, organized by the Paint Research Association (PRA), in Prague, Czech Republic, October 17–18, 2006.     

Synergistic effect of hindered amine light stabilizers/ultraviolet absorbers on the polyvinyl chloride/powder nitrile rubber blends during photodegradation

The photostability of hindered amine light stabilizer (HALS) and ultraviolet absorber (UVA) on the blends of plasticized poly (vinyl chloride) (PVC) and powder nitrile rubber (NBR) has been studied with a Xenon Test Chamber. The digital photos, color differences, attenuated total refection‐Fourier transform infrared (ATR‐FTIR) spectra and mechanical properties of the blends have been determined. HALS combined with UVA effectively protects PVC/NBR blends from yellowing and restrains the decrease of elongation at break of the blends. The synergistic phenomenon is ascribed to the different photostable mechanisms of HALS and UVA at different photo aging stages. The color of PVC/NBR control sample quickly changes into yellow at the first 400 h of irradiation, due to the polyenes structures that induced by the double bonds of butadiene in NBR. From 400 to 800 h, crosslinking dominates and the amount of polyenes decreases, resulting into the decrease of color change. At the early stage of irradiation, chain‐scission of polymer takes the predominant place, and the tensile strength decreases. But during the latter stage, crosslinking takes the predominant place and the tensile strength increases slightly. HALS and UVA have a little effect on the maintaining of elongation at break of PVC/NBR blends. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

Long-term weathering behavior of UV-curable clearcoats: Depth profiling of photooxidation,UVA, and HALS distributions

The long-term weathering performance of two UV-curable clearcoat systems was studied using in-plane microtomy in combination with infrared spectroscopy, UV spectroscopy, and ESR spectroscopy. Oxygen transport characteristics were also studied using the half-time method. The photooxidation versus depth profile was highly dependant on the presence of hindered amine light stabilizers (HALS) for both coating systems. Ultraviolet light absorbers (UVA) had little effect on the photooxidation profile. A photooxidation gradient was formed in both clearcoats due to a reduction in oxygen solubility when compared to standard thermoset clearcoats. This gradient was only seen in formulations not containing HALS. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.     

A study on the photostabilizer additives on the textile fiber reinforced polymer composites: Mechanical,thermal, and physical analysis

The effect of photostabilizers on the mechanical, thermal, and physical properties of textile fiber reinforced polymer (T‐FRP) composites was investigated. In the first phase of this study, the effect of different concentrations of ultra violet absorber (UVA), hindered amine light stabilizers (HALS) and antioxidants (AOs) into T‐FRP composites for unweathering condition are examined. Mechanical tests were performed as well as differential scanning calorimetry (DSC) analysis for thermal properties. According to test results, there is no significant effect of photostabilizers on the mechanical and thermal properties of the T‐FRP composites. In the second phase of the study, the influence of the photostabilizers on the durability performance of T‐FRP composites is focused under the accelerated UV weathering condition by the help of tensile testing, thermal analysis, and color measurements. According to test results, only about 5% loss in mechanical properties (25% loss for composites without additives) can be observed after 240 h of UV weathering with HALS and UVA addition at adequate concentrations. In addition, AOs can be considered as a strong stabilizer on physical properties with lower color change values. This work shows that the efficiency of the photostabilizers is highly dependent on the type, concentration, and weathering time. POLYM. ENG. SCI., 58:1082–1090, 2018. © 2017 Society of Plastics Engineers     

Theoretical and experimental assessment of UV resistance of high-density polyethylene: Screening and optimization of hindered amine light stabilizers

Hindered amine light stabilizers (HALS) are widely used chemical stabilizers for preventing polymer degradation. In this study, the effects of type of HALS and its content in high-density polyethylene (HDPE) over the stabilization process are investigated employing density functional theory (DFT) and experimental approach. The electrophilicity index of four types of commercial HALS are compared by DFT to select the most effective one. Besides, the HDPE sample containing a phenolic antioxidant and different contents of the selected HALS are experimentally exposed to UV irradiation. The effect of HALS content on the changes in chain microstructure and molecular weight of HDPE are evaluated using gel permeation chromatography and frequency sweep rheometry. In the absence of HALS, HDPE suffers degradation and the phenolic antioxidant causes chain scission. However, by adding HALS, the chain branching and crosslinking mechanisms are predominant. The results of FTIR, DSC, and tensile analyses follow similar trends, revealing that the best stabilization performance corresponds to adding 600 ppm HALS to HDPE.     

ABS的耐候老化研究

主要对丙烯腈–丁二烯–苯乙烯塑料(ABS)的不同耐候性能进行了研究,通过人工加速老化试验,对比老化前后色差变化,考察光稳定剂对ABS耐候性能的影响。结果表明,添加光稳定剂能够有效地改性ABS耐候性能;受阻胺光稳定剂与紫外线吸收剂复配使用对ABS有很好的耐候效果;适当地提高受阻胺光稳定剂含量有利于提高ABS的耐候性能。     

聚甲醛、PET及PVC的抗老化配方研究进展

综述了聚甲醛(POM)、PET、PVC及其改性材料的抗老化研究的新进展。POM、PET及PVC/ABS的抗老化配方采用抗氧剂/紫外线吸收剂复配体系,而PVC及其他改性材料则采用紫外线吸收剂体系,若再加入适量的受阻胺光稳定剂,可以改善材料的抗老化效果。