抗氧剂、光稳定剂在聚碳酸酯和改性材料中的应用技术

简单介绍了抗氧剂和光稳定剂作用、功能和类别.列举了不同抗氧剂、光稳定剂条件下聚碳酸酯和ABS改性合金材料热老化试验的数据:亚磷酸酯抗氧剂和受阻酚抗氧剂的配合体系,可以有效保护聚碳酸酯的相对黏度和色泽,提高PC/ABS合金拉伸强度和缺口冲击强度;使用紫外线吸收剂可以有效地延缓聚碳酸酯变黄并适当保持强度;经试验或实际应用确...     

Stabilization of nigeria natural (havea) rubber with bound antioxidant added as masterbatch

Nigeria natural rubber concentrates in a newly synthesized antioxidant were added as conventional additives for normal natural rubber. The natural weathering, thermal and photooxidative protective performance of the adduct were examined by measurement of the carbonyl index and induction periods. From the results obtained, it is concluded that the addition of this new antioxidant in the form of masterbatch appears to be a better practical way of incorporating it into natural rubber simply by dilution of natural rubber. The bound stabilizers were found to be resistant to leaching.     

Chemiluminescence in thermal oxidation of ABS

Two concepts in the chemiluminescence research-the heterogeneous model and the kinetic approach-are discussed. The analysis of published data obtained by a highly sensitive photon-counting system reveals the contradictory nature of the heterogeneous model and proves its inconsistency. On the other hand, the kinetic approach has been successfully applied to evaluation of thermal oxidation in a variety of systems, ABS compositions in particular. Emulsion grade ABS were found to be essentially less stable than ionic mass polymerization products. Among the antioxidants studied, Santonox R is clearly more efficient than Irganox 1076. In emulsion grades the superiority of Santonox R to Irganox 1076 is reflected primarily in larger induction period, while in ionic resin it is mostly due to smaller oxidation rate constant values. The introduction of UV stabilizers by themselves has no influence on durability in either ionic or emulsion resins. Similarly to systems without UV stabilizers, Santonox R is more efficient than Irganox 1076 in mixtures with UV stabilizers as well. The comparative study of various ABS-coloring agent compositions by chemiluminescence and DSC reveals much greater sensitivity of the former. While DSC lets one make only a trivial conclusion that the introduction of an antioxidant improves stability, chemiluminescence shows the differences in durability as large as 3 to 4 times for the samples DSC fails to distinguish. In addition, chemiluminescence furnishes a significant insight on the factors affecting stability. The DSC thermal oxidative stability data can be related to resistance to oxidation during processing, whereas the chemiluminescence results are expected to be useful in predicting materials' lifetime at service temperatures.     

加氢润滑油基础油光稳定剂的研制

应用正交试验设计的方法,研究了自制的紫外辐射吸收剂、受阻胺类光稳定剂及抗氧剂对兰州石化总厂生产的125N加氢润滑油基础油抗光氧化降解性能的影响.发现以上各种添加剂均能提高加氢润滑油基础油抗光氧化降解的能力.在相同的辐射剂量下,添加四甲基受阻胺类光稳定剂的加氢基础油抗光氧化降解的能力优于添加五甲基受阻胺类光稳定剂;添加苯并三唑型紫外辐射吸收剂比添加二苯甲酮型紫外吸收剂的加氢基础油抗光氧化降解的能力强;紫外辐射吸收剂与受阻胺类光稳定剂之间以及紫外辐射吸收剂与抗氧剂之间均存在协同作用.并且发现,四甲基受阻胺类光稳定剂与酚类抗氧剂之间存在协同作用,而五甲基受阻胺类光稳定剂与酚类抗氧剂之间存在反协同作用.评价结果表明:添加自制的高效无灰复合型光稳定剂1.5g·L-1可使兰州炼油化工总厂生产的125N加氢润滑油基础油保持良好的光稳定性,其透光率、色度均优于添加2 g·L-1目前最好的有机镍盐配合物型光稳定剂.     

Boreal forest conifer extracts: potential natural additives for acrylic polyurethane coatings for the protection of heat-treated jack pine

Among consumers, heat-treated wood recently gained more importance due its attractive darker color along with several other advantages such as improved biological resistance, dimensional stability, and thermal insulating properties. However, exposure to the exterior environment drastically changes the attractive darker color of this product. From dark brown, it becomes almost white. For this reason, development of a nontoxic transparent coating which can protect the heat-treated wood from photodegradation is very important. Addition of UV stabilizers (UV absorbers, HALS, antioxidant) is necessary for transparent coatings in order to filter the harmful UV/VIS radiation. In this present study, the effectiveness of natural antioxidants, extracted from conifer barks or needles from trees in protecting the color of wood, as additives to acrylic polyurethane coating is examined. Also, their UV/VIS absorption capacities and semi-quantitative component analyses have been presented. The toxicity of these new products was also evaluated on human normal skin cells due to ever increasing environmental legislation. The chemical modification of acrylic polyurethane coating containing conifer bark and needle extract were examined by ATR–FTIR analysis. Promising results were obtained for these natural antioxidants which showed very high UV absorption characteristics and antioxidant activity.     

Effects of two antioxidants with different degrees of steric hindrance on the thermal-oxidative aging properties of ABS resin

ABS resin is easily oxidized and deteriorated during use or processing. The addition of antioxidants is an effective method for improving ABS oxidation. The hindered phenol antioxidant DBHMIE and the asymmetrically hindered 245 were added separately or together to ABS; the oxidation induction temperature of ABS increased by 10.6, 12.1 and 14°C, with the addition of DBHMIE, 245 and their combination, respectively, and the initial decomposition temperature T3% increased by 29.7, 16.2 and 51.3°C, respectively. The addition of these two antioxidants to ABS did not greatly affect the mechanical properties of the material, but the impact strength increased by 2.24 kJ/m² when both antioxidants were added together. During the thermal aging test, the decomposition temperature of the ABS splines prepared with the combined antioxidants increased during the first few cycles. The impact strength of the splines prepared with the combined antioxidants was the highest, with the smallest decrease of only 5.18%. The yellow index of the spline prepared with the combined antioxidants was between those of splines prepared with the antioxidants added alone. The combination of DBHMIE and 245 induced synergistic effects, improved thermal-oxidative aging resistance, and improved and protected the toughness of ABS resin.     

医用聚氯乙烯耐辐照改性研究进展

综述了热稳定剂、抗氧剂和光稳定剂改性聚氯乙烯（PVC）的耐辐照机理,以及不同助剂组合添加产生的协同效应。对近年来有关PVC材料耐辐照改性方面的研究进展进行了总结,并对耐辐照PVC材料的发展前景进行了展望。     

耐老化ABS/PVC共混塑料的研制

以国产丙烯腈-丁二烯-苯乙烯三元共聚物(ABS）、聚氯乙烯(PVC)为主要原料,配以紫外线吸收剂、抗氧剂等助剂,研制了耐老化ABS／PVC共混塑料,并对其加工性能、力学性能及耐老化性能进行了研究。结果表明,在ABS和PVC质量比为60：40,添加抗氧剂1076和紫外线吸收剂UV-327(两者用量均为ABS／PVC共混塑料质量的0.5％)后,所制得共混塑料不仅具有优良的力学性能,而且还具有良好的耐老化性能。     

耐候型聚甲醛复合物的制备与性能研究

将二甲基硅氧烷、紫外线吸收剂、光稳定剂、抗氧化剂、紫外线屏蔽剂、甲醛吸收剂与聚甲醛（POM）共混制备了耐候型POM,分析了光老化、热氧老化、水热老化实验后耐候型POM的性能、结构变化及助剂的分布情况。结果表明,耐候助剂提高了POM的力学性能保持率;POM的老化过程主要发生在无定形区域,且对光尤为敏感、热氧次之,对水热的影响较小;耐候助剂主要分布于无定型区域,在发挥耐候效果的同时,由于紫外线照射,本身会被消耗。     

不饱和树脂玻璃钢复合材料防老化研究进展

综述了不饱和树脂基玻璃钢复合材料(GFRP)防老化方面的新近研究进展,包括新型GFRP表面涂层及不饱和树脂的防老化添加剂(紫外线吸收剂、受阻胺光稳定剂和抗氧剂等)及树脂的改性。将抗氧剂和其他添加剂(例如某些环氧化合物)并用,可取得较好的效果。     

LLDPE用亚磷酸酯稳定剂国产化研究

在考查国产亚磷酸酯以及引进亚磷酸酯稳定剂在线性低密度聚乙烯(LLDPE)中的热加工性能的同时,通过亚磷酸酯与抗氧剂、多种助剂等复合使用以及其耐水解性能的研究,为亚磷酸酯稳定剂国产化提供了依据。     

Quantitative determination of antioxidants and ultraviolet stabilizers in polymers by high performance liquid chromatography

The quantitative determination of antioxidants and ultraviolet (UV) stabilizers in a polymer matrix has been standardized using HPLC. The additives were extracted out of the matrix using low boiling solvents in order to minimize the degradation of additives at elevated temperatures. Carbon tetrachloride and tetrahydrofuran have been found to be most suitable solvents for low density polyethylene and polypropylene respectively. The method has been found to be highly reproducible and the standard deviation is very low. This method does not suffer from the problems like overlapping frequencies as observed in spectroscopic methods.     

Study of polyethylene photodegradation in formulations with a system of interacting photostabilizers and antioxidants

The accelerated UV photodegradation process of low-density polyethylene films, formulated with two photostabilizers and two antioxidants, was studied to evaluate the effect of different combinations of UV stabilizers and antioxidants on the overall photodegradation process. An experimental design, consisting of 33 formulations with different additive ratios and a blank, was used to evaluate the performance of the four mixed additives. From each formulation, 200 micron-thick films were produced by the extrusion-blowing process. Samples from these films were submitted to accelerated UV aging, and the polymer degradation was measured by carbonyl group evolution, molecular weight distribution changes, and maximum elongation loss. The effect of the additive combination on the different degradation reactions is discussed qualitatively by using “relative variables” and a triangular diagram. © 1996 John Wiley & Sons, Inc.     

Studies on the interaction of photoreactive light stabilizers and UV-absorbers

Coatings, like all organic substances, are submitted to photoageing during their life time. Ultraviolet light absorbing additives (UVAs) and hindered amine light stabilizers (HALS) often are added to improve their performance. These additives can be lost by migration to the surface, where they are exposed to physical depletion, as well as through photodegradation of the molecule itself. Modifying hindered amine light stabilizers by introducing a photoreactive site gives the possibility to fix the stabilizing molecule onto the polymer matrix. The influence of the presence and the type of UV absorbers onto the photografting reaction will be discussed.     

Some Aspects of Thermal and Photochemical Autoxidation

Following an outline of the pioneering work of Haber's School, emphasis is placed on a critical review of the most important recent achievements. These embrace, in the area of thermal autoxidation: the concept of critical antioxidant concentration, the multiple effects of heavy metals (including catalyst-inhibitor conversion), the development of new synergistic antioxidant combinations composed of free radical acceptor and peroxide decomposer and, finally, Denisov's direct experimental evidence for the reaction of heavy metals with molecular oxygen in organic media in support of Uri's trace metal hypothesis of the general mechanism of the initiation of autoxidation. The following recent advances in the field of photochemical autoxidation are described: photosensitized initiation by trace metals and its inhibition, the singlet oxygen hypothesis, the inadequacy of phenolic antioxidants and the reliance on UV absorbers, the importance of energy transfer in photochemical protection leading to new stabilizers. A very recent innovation which is relevant to both thermal and photochemical autoxidation is highlighted, i.e., the development of new α-dithidiketone chelates, particularly bis (stilbenedithiolate) nickel (= NiS₄C₄Ph₄or, abbreviated, NiSDT) as antioxidants which combine in a unique way the properties of free radical acceptors, peroxide decomposers and UV stabilizers. They were then found to be the most powerful antioxidants for polyethylene and polypropylene.     

抗老化助剂对尼龙6耐老化性能的影响

通过热氧老化评估了不同抗氧剂对尼龙6(PA6)耐黄变性能的影响,优选一组效果较好的抗氧剂作为基础抗氧剂配方。通过QUV 340 nm加速老化实验,分别评估了添加不同光稳定剂的PA6样品老化后其色差(△E)、黄色指数变化值(△YI)及拉伸强度保留率随时间的变化情况;通过长期热氧老化实验分别评估了样品在不同温度下,其△E、△YI及拉伸强度保留率随时间的变化情况。结果表明:Sunox508/Sunox626抗氧体系中加入光稳定剂会降低抗氧剂效果,其中加入Sunovin 5524/Sunovin 770影响最小。     

Photooxidative stability provided by condensed tannin additives in acrylic-based surface coatings on exterior exposure

Condensed tannins, also known as proanthocyanidins, have been added as functional additives to acrylic-based clear coatings to promote polymer coating longevity and also stabilize timber color on accelerated and exterior weathering. When added at <?0.5% w/w content, native tannins and tannins modified with maleate groups extended coating performance >?20% compared to commercial hindered amine light stabilizers (HALS) and phenolic stabilizers used at comparable coating loadings. Other tannin chemical modifications such as methylcarboxylate groups were also associated with greater coating longevity beyond that achieved with the synthetic UV and antioxidant additives. This study has also revealed that tannin addition to acrylic coatings can act to photostabilize timber coloring on exterior exposure. While tannin use can contribute color to coatings, any color was rapidly bleached on UV exposure with a dependency on tannin content, degree of modification, and coating formulation pH. Moreover, through manipulating tannin addition levels, this tannin decolorization could offset typical wood darkening associated with UV exposure to provide low or no wood color change over longer exposure periods. With the photooxidative stability efficacy of tannins established on exterior exposure, condensed tannins in native and modified form offer potential as sustainable functional additives for the coatings sector.     

高性能低VOC环保PC/ABS合金材料的制备

以聚碳酸酯(PC)、丙烯腈–丁二烯–苯乙烯塑料(ABS)为基体树脂,加入聚烯烃弹性体(POE)、抗氧剂及其它助剂共混挤出造粒,制成低挥发性有机化合物(VOC)的环保PC/ABS合金材料。在用增韧剂POE及抗氧剂对PC/ABS体系进行改性的同时,探讨PC/ABS基料、增韧剂、抗氧剂对PC/ABS合金的力学性能、VOC及气味等级的影响,从而得到具有高性能、低VOC、低气味的环保PC/ABS合金材料,以期在汽车内饰件等方面得到应用。     

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     

Influence of different types of UV absorber/UV stabilizer combination on the photodegradation of PC/ABS blend

The polycarbonate/poly(acrylonitrile butadiene styrene) blends, (PC/ABS), are mainly degraded by sunlight known as photodegradation when exposed to outdoor conditions. It is the ultraviolet (UV) radiation that is responsible for the degradation of the blend. To stabilize against the harmful UV radiation and to scavenge the radical species which arise from UV or thermally induced degradation of the PC or the ABS, UV absorbers, and UV stabilizers are used. In this article three different UV absorbers namely, Tinuvin 1577—hydroxyphenyl triazine type, Cyasorb 5411—benzotriazole type, Uvinul 3030—cyanoacrylate type, and two different UV stabilizers, Tinuvin 765—monomeric hindered amine type, Tinuvin 622—oligomeric hindered amine were compounded in different combinations with PC/ABS blend at 240°C using a twin screw extruder. Accelerated aging of the compounded sample was done by Atlas Suntest apparatus. The photodegradation studies were done using UV–vis, attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy, and Yellowing index measurement. The molecular weight of the compounded sample before aging was determined by gel permeation chromatography (GPC). It was found that samples protected with hydroxyphenyl triazine type UV absorber and oligomeric hindered amine show the best result for decreasing the degradation products, oxidation rate, and yellowing of the PC/ABS blend. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012