不同层板离子及插层类水滑石对PVC热稳定性的影响

分别合成了不同层板离子、不同价态无机酸根及有机酸根插层、不同直链链长插层类水滑石,采用热老化烘箱法、刚果红法、转矩流变仪探究了对聚氯乙烯(PVC)热稳定性能的影响。结果表明,类水滑石层板中引入稀土元素及增加离子的数目可提高PVC的热稳定性;不同价态无机酸根及有机酸根插层类水滑石中,二价酸根插层的类水滑石均表现出最佳的热稳定性能;类水滑石插层中随着有机酸碳链的不断增长,热稳定性出现了先增强后降低的趋势。     

二硝甲基唑类含能化合物的研究进展

二硝甲基唑类化合物是一类结构新颖的多氮含能化合物。综述了二硝甲基唑类化合物的合成方法和反应性质,并对部分含能化合物的性质进行了介绍。结果表明,二硝甲基唑类化合物的密度较大,且具有较高的正生成焓,但自身热稳定性较差,以其为阴离子合成出的离子盐具有较好的热稳定性。目前,二硝甲基唑类化合物的合成方法较成熟,但理论方面的研究不够深入。     

Comparison of madder (Rubia tinctorum L.) and weld (Reseda luteola L.) total extracts and their individual dye compounds with regard to their dyeing behaviour,colour, and stability towards light

This paper reports on the colorimetric properties of natural dyes from madder and weld plants. For both crops, a comparison is made among several individual dye compounds and the total plant extracts. Dyeing properties, colour properties and colour stability have been studied. Insight has been gained into the role of the major dye compounds present in the plant. For madder as well as for weld, the use of the total plant extract is considered to be advantageous over the use of individual dye compounds in terms of solubility, colour tone and stability towards light, and non‐coloured components present in the plant extract are considered to be responsible for increasing the solubility and the stability of the dye compounds.     

含受阻胺结构的苯并三唑光稳定性和热稳定性研究

测试了4种2-[2’-羟基-3’-叔丁基-5’-（3-丙酸-4-哌啶酯基）苯基]-2H-苯并三唑结构类光稳定剂紫外吸收光谱、光稳定性及热稳定性。4种化合物在270～400nm均有较强的吸收峰,与引入受阻胺结构前苯并三唑光稳定剂相比．紫外吸收波长和摩尔消光系数不变。4种化合物的光稳定性和热稳定性明显高于引入受阻胺结构前的苯并三唑光稳定剂。光老化12h后,4种化合物仅分解3．2％～6．9％,引入受阻胺结构前苯并三唑则分解35．0％～36．3％。热稳定性测试表明。4种化合物失重1％时的温度为264～272℃．而引入受阻胺结构前苯并三唑失重1％时的温度分别为227℃和235℃。该类化合物分子内同时具有紫外吸收剂和自由基捕获剂两种功能,为高效光稳定剂。     

提高煤焦馏分油储存安定性的研究

为改善煤焦馏分油在贮存及运输过程中的安定性,以甲苯、四氢化萘、萘作为模拟基础油,以苯酚、氧芴、吲哚、喹啉、噻吩分别模拟含氧、含氮和含硫化合物,研究了单一和复合模拟化合物对基础油安定性的影响。结果表明：单一模拟化合物中吲哚对基础油的安定性影响最大,当两种或两种以上复合模拟化合物同时存在于基础油中时,由于相互作用,基础油的不稳定性加剧。在轻油、洗油和蒽油3种煤焦馏分油中,分别加入0．1％的稳定剂,常温储存40天后,其色度、胶质和沉渣等安定指标能够满足国标一级品柴油的规格要求。     

8种双阳离子吡啶基离子型化合物的合成、表征与热稳定性能

吡啶分别与4种二卤代烃进行N-烷基化反应得到4种双阳离子吡啶基离子型卤化物,再与硝酸银进行阴离子交换得到4种相应的硝酸盐。分别对它们的结构进行了1HNMR1、3CNMR表征,并测定了它们的溶解性及热稳定性。结果表明,这8种双阳离子型化合物的溶解性相似,易溶于极性溶剂,难溶于非极性溶剂。在8种双阳离子吡啶基离子型化合物中,氯化物的热稳定性要高于相应的硝酸盐。随着连接双阳离子的烃基增大,相同阴离子的双阳离子化合物的热稳定性增加。而且双阳离子吡啶基离子型化合物的热稳定性高于含相同阴离子的单阳离子吡啶基离子液。     

有机光致变色化合物光化学稳定性能研究

良好的光化学稳定性是光致变色化合物实现工业实际应用的前提和保证。研究比较了几种有机光致变色化合物的可逆光致变色性的热稳定性和耐疲劳性等光化学稳定性能,提出了提高光化学稳定性的几种可行方法。     

The Quality,Stability, and Bioactive Compound Composition of Virgin and Refined Organic Grape Seed Oil

Samples of virgin and refined organic grape seed oil were studied for their physicochemical quality, oxidative stability, and the bioactive compounds they contained. All of the samples were within the limits established by the Codex Alimentarius with regard to their quality parameters. Lutein, zeaxanthin, β‐carotene, α‐tocopherol, and catechin were the bioactive compounds analyzed, and the virgin oil afforded more significant results. No measurable amounts of zeaxanthin and β‐carotene were observed in the refined oil, most likely due to the refining process that was carried out at high temperatures. The oxidative stability index decreased with increasing temperature, whereas the air flow had no effect on the stability index. The optimal parameters for the oxidative stability are 80 °C and a flow rate of 15 L h^?1, and the virgin oil sample showed the best oxidative stability, possibly because it was not subjected to any treatment after extraction. The results from this study suggest that it would be preferable to consume virgin instead of refined grape oil because it is a better source of bioactive compounds and has a higher stability when heated.     

Flavor stability of soybean oil based on induction periods for the formation of volatile compounds by gas chromatography

Although previous research showed that volatile compounds detected by gas chromatography (GC) correlated well with flavor scores, no instrumental or chemical method has been available to predict flavor stability of vegetable oils reliably. A direct GC method was tested to predict flavor stability of soybean oil by measuring induction periods based on the time required for rapid formation of volatile compounds. By this technique, induction periods of 9, 5 and 0 days were obtained with oils containing a combination of tertiary butylhydroquinone (TBHQ) and citric acid (CA), CA only and no additives, respectively. Addition of methyl silicone to the oils containing CA or CA+TBHQ did not increase their stability. Prominent peaks identified by gas chromatography-mass spectrometry included: pentane, hexanal, 2-heptanal, 2,4-heptadienal, 2-decenal and 2,4-decadienal. Measures of total volatile compounds, pentane and 2,4-decadienal were best related to deteriorative changes. High correlation coefficients were obtained between individual and total volatiles with flavor scores. This study showed that flavor stability of oils can be predicted by determining induction periods based on the formation of volatile compounds.     

聚乙烯滚塑专用料的研制

介绍了聚乙烯共混改性制备滚塑专用的方法，讨论了添加不同品种、不同含量抗氧剂对专用料加工稳定性能和长期热氧老化性能的影响，添加不同呈光稳定剂对专用料耐光老化性能的影响。另外，还分析了专用科研磨后粉料的性能。经国内多家主要滚塑厂及生产应用表明，专用料的性能指标与Ｕ．Ｃ．ＣＤＮＤＢ７１４８相当，完全能够满足国内滚塑厂家的要求。     

金属有机RReO3化合物研究进展

RReO₃是一种过渡金属有机化合物，其中，甲基三氧化铼是最早被发现的一种稳定的RReO₃型化合物，然而由于当时未能得到一种有效的合成路线，所以对甲基三氧化铼的研究没有引起重视。直到1988年德国Herrmann W A等发明了一种简便有效的合成方法，并且发现这类化合物可以高效催化烯烃环氧化反应后，RReO₃型化合物才引起重视。综述了迄今为止报道的含有不同R基团的RReO₃类化合物的合成方法，主要包括锌路线和锡路线两种合成方法，系统阐述了不同类型R基取代基对化合物稳定性的影响，同时总结了不同类型RReO₃型化合物催化性能的研究进展。然而，除甲基三氧化铼外，目前发现的大多数RReO₃型化合物在空气及潮湿环境下稳定性较差，限制了其催化应用。分析了影响催化剂稳定性的因素，并建议通过深入研究分子构效关系，探讨稳定性与催化性能的作用规律，从而指导催化剂的设计与合成，并对未来的发展方向进行展望。     

对甲基苯甲酸铈对PVC热稳定性能的影响

用复分解法制备了对甲基苯甲酸铈,确定产物的分子式为Ce(C8H7O2)3·2H2O.研究了对甲基苯甲酸铈对聚氯乙烯(PVC)的热稳定性能的影响.结果表明,对甲基苯甲酸铈单独作为PVC热稳定剂时,其热稳定性和抗变色性都不强.将对甲基苯甲酸铈与其他热稳定剂联合进行二元、三元及四元复配,产物的协同作用良好,热稳定性有所提升;...     

Effect of titanium compounds on thermooxidative properties of stabilized polypropylene

The effect of titanium compounds on thermooxidation stability of stabilized polypropylene was studied. It was found that the presence of titanium compounds shortens the induction period of PP oxidation. This phenomenon is brought about by the thermal reactions of titanium compounds with antioxidants which take place during polymer processing. The first step is the reaction of Ti? Cl with OH groups of phenolic antioxidant, which gives rise to a colored titanate and HCl. Hydrogen chloride functions as a Friedel-Crafts catalyst for degradation and dealkylation of phenolic antioxidants. The products of degradation have a very low stabilization efficiency. Hydrogen chloride acceptors suppress antioxidant degradation and increase the polymer stability even in the presence of small amounts of titanium compounds.     

Effect of structure on the thermal stability of photocurable urethane acrylate formulations

The effect of structural segments on the thermal stability of photocurable urethane acrylates was studied. A series of model compounds, where one segment of the molecular structure was varied at a time while keeping the remainder of the molecule unchanged, was tested for thermal stability. The results from this study indicate a prominent equivalent weight effect: Increasing the equivalent weight decreases the thermal stability within a given series of model compounds. Polyol-based urethanes were found to be more stable than their amine counterparts. Of the hydroxy-terminated starting materials, polycaprolactones were found to produce the greatest thermal stability, whereas polyethers resulted in the least stable photocurable materials. The diisocyanate segment exhibits a marked effect on the thermal stability of the cured material also. Surprisingly, the dicycloaliphatic diisocyanates resulted in greater stability than the aromatic diisocyanates, while the monocycloaliphatic diisocyanates yielded the least stable materials in the model compound series tested.     

芳香化合物在纤维素衍生物/离子液体毛细管色谱柱上的定量结构-色谱保留相关性研究

运用量子化学中的密度泛函理论（DFT）计算芳香化合物溶质分子结构描述参数,借助逐步回归法建立芳香化合物在纤维素三苯基氨基甲酸酯（CTPC）/1-辛基-3-甲基咪唑四氟硼酸盐（[OcMIM]BF4）毛细管色谱柱上的定量结构-色谱保留之间的QSRR模型,并对模型的稳定性与适用性进行了考察。结果表明,芳香化合物的容量因子对数与溶质分子结构描述参数MR、logP、GE、EHOMO和DIP之间有良好的多元线性相关性,表明芳香化合物与固定液CTPC/[OcMIM]BF4间的主要作用力是分子色散力、诱导力、氢键作用和疏水作用。所建立的QSRR模型线性相关性、稳定性良好,具有良好预测芳香化合物色谱参数的能力。     

Antioxidative and synergistic effects of bene kernel and hull oils during oxidation of virgin olive oil

Total amounts of conjugated diene hydroperoxides and carbonyl compounds of a virgin olive oil (VOO) and its purified form as affected by 0.1–6% w/w bene kernel (BKO) and hull (BHO) oils were monitored during 16 h heating at 180°C. The VOO was more prone to the production of off‐flavour carbonyl compounds than to the formation of conjugated diene hydroperoxides. The VOOs oxidative stability decreased significantly due to the removal of the indigenous antioxidative compounds. Oxidative stability, especially regarding the secondary oxidation, significantly improved with increasing concentrations of the BKO than with those of the BHO.     

Color stabilization of poly(vinyl chloride) against high-energy electron irradiation

Color stability in irradiated PVC may be achieved by (1) structural modification to block dehydrochlorination, (2) addition of radiation protectors, or (3) addition of radical scavengers. This study explores the latter approaches. Twenty-six compounds representing a variety of structural types were screened for their effectiveness as measured by subsequent color development. Fifteen of the compounds imparted partial or complete postirradiation stability. Possible stabilizer mechanisms are discussed.     

Effect of Stripping Methods on the Oxidative Stability of Three Unconventional Oils

Stripped and non-stripped oils from Sclerocarya birrea [marula oil (SCO)], Aspongopus viduatus [melon bug oil (MBO)] and Agonoscelis pubescens [sorghum bug oil (SBO)], traditionally used for nutritional applications in Sudan, were investigated for their fatty acid and tocopherol composition, and their oxidative stability. Three stripping methods were used, phenolic compounds extraction, silicic acid column, and aluminum oxide column. The stripping methods did not affect the fatty acid composition. Non-stripped SCO, MBO and SBO contained oleic, palmitic, stearic and linoleic acids, which were not significantly (P < 0.05) different than stripped SCO, MBO and SBO. The stripping methods’ effect on the tocopherol composition of the studied oils, the total amount of tocopherol in non-stripped oils decreased by extraction of phenolic compounds, mean that part of the tocopherols was extracted with the phenolic compounds. No traces of tocopherols were found in oils stripped using silicic and aluminum columns and the tocopherols were eliminated during the stripping processes. The stability of SCO, MBO and SBO oils was 43, 38 and 5.1 h, respectively, this stability decreased by 22.0, 37.6 and 23.5%, respectively after extraction of phenolic compounds. This stability decreased by 96.9, 98.2 and 90.2% respectively, when stripped using the aluminium column and decreased by 92.6, 96.1 and 86.3% when stripped by the silicic column. It is possible to assume that the tocopherols and phenolic compounds play a more active role in the oxidative stability of the oils than the fatty acid composition and phytosterols.     

复合溶剂改善桦甸页岩柴油安定性的研究

采用萃取分离方法从桦甸页岩柴油中分离氮化物特别是碱洗氮化物具有高效性,实验结果表明,用溶剂A-无机酸的复合试剂以剂油比为0.5时精制桦甸页岩柴油,明显的降低了桦甸页岩柴油的色度,与此同时大大提高了桦甸页岩柴油的安定性,将桦甸页岩柴油经复合溶剂处理后再经碱洗,可有效的除去影响安定性的酸性组分和氮化物,使油品的颜色得到明显...     

稀土氧化物和硫酸盐对聚氯乙烯热稳定作用的研究

本文着重研究了不同稀土无机化合物对聚氯乙稀热稳定性的影响,并对其作用机理进行了初步探讨。