多臂端羧基聚硅氧烷的可控合成及表征

以八甲基环四硅氧烷(D4)、苯基三(二甲基硅氧烷基)硅烷(PTDMS,俗称三氢封头剂)或四(二甲基硅氧基)硅烷(TDMS,俗称四氢封头剂)为原料,通过开环聚合法合成了三端氢基聚硅氧烷(PDMS-H3)和四端氢基聚硅氧烷(PDMS-H4);再将其与甲基丙烯酸叔丁酯(t-BMA)在氯铂酸-四氢呋喃(THF)溶液催化下通过硅氢加成反应得到三端酯基聚硅氧烷(PDMS-t-BMA3)和四端酯基聚硅氧烷(PDMS-t-BMA4);最后在浓硫酸催化下水解制得三端羧基聚硅氧烷(PDMS-COOH3)和四端羧基聚硅氧烷(PDMS-COOH4)。采用FT-IR、1H NMR和GPC对各阶段产物的结构和摩尔质量及其分布进行表征。结果表明,通过开环聚合、硅氢加成、酸性水解三步反应能够获得结构清晰、摩尔质量可控的多臂端羧基聚硅氧烷,且叔丁酯基聚硅氧烷酸性水解反应效率高,后处理简单,对硅氧烷主链的影响较小。     

羟烃基聚硅氧烷的制备及亲水性能

以八甲基环四硅氧烷(D4)、四甲基环四硅氧烷(D4H)和六甲基硅氧烷(MM)为原料实施开环聚合反应,制备出不同含氢量的聚二甲基硅氧烷;含氢硅氧烷与乙酸乙烯酯进行硅氢加成反应,在硅氧烷大分子侧链上引入酯基;然后碱性条件下进行醇解反应,最后成功合成了不同羟烃基含量的聚硅氧烷.对产物的结构、乳化稳定性、乳液粒径及成膜的表面性...     

烃羧基硅油制备的新工艺研究

以单体甲基丙烯酸甲酯和大分子的聚甲基氢硅氧烷为原料进行硅氢加成反应和水解反应,将含氢硅油改性合成烃羧基硅油,反应收率较高,并通过实验确定了最佳反应条件。     

环氧基改性硅油的合成与表征

以端环氧基烯丙基聚醚、含氢硅油为原料,采用第二代铂金催化剂,通过硅氢加成反应制备环氧基改性硅油。研究了反应时间、反应温度、物料配比对反应转化率的影响。通过单因素试验得到最佳反应条件为:反应时间7 h、反应温度100℃、含氢硅油与端环氧基聚醚的摩尔比为1∶1.1。在此条件下含氢硅油的转化率为91%。红外表征证实,产物接上了端环氧基烯丙基聚醚。     

氯丙基聚硅氧烷的合成进展

介绍了氯丙基聚硅氧烷的3种主要合成方法：γ－氯丙基甲基二氯硅烷的水解缩聚，含氢环体与氯丙烯加成形成的取代环体的开环聚合及含氢硅油与氯丙烯的硅氢加成，通过比较，认为含氢硅油与氯丙烯的硅氢加成反应是较理想的合成方法。     

侧链可降解聚硅氧烷

甘肃农业职业技术学院的冯武将烯丙基缩水甘油醚与自制的聚乳酸-聚乙二醇共聚物在锌粉催化下反应，得到4-（3-烯丙氧-2-羟基）丙氧基封端的聚乳酸-聚乙二醇共聚物；再与含氢硅油进行硅氢加成反应，制得带可降解侧链的亲水性聚硅氧烷；并测定了其相对密度、折射率、数均摩尔质量、重均摩尔质量及其分布指数，胶膜的水接触角。     

基于氢键自组装的侧链聚硅氧烷液晶的研究进展

通过与传统的侧链聚硅氧烷液晶的对比,阐述了氢键自组装侧链聚硅氧烷液晶独特的优点;简要介绍了羧基-羧基体系、羧基-吡啶体系、羧基-咪唑体系氢键自组装侧链聚硅氧烷液晶的研究现状,此外,还根据类似的非聚硅氧烷型液晶体系设想了羧基-氨基吡啶体系氢键自组装侧链聚硅氧烷液晶和酚羟基-吡啶体系氢键自组装侧链聚硅氧烷液晶;并概述了液晶常用的表征方法.     

环氧改性硅油

华南理工大学的孙海燕等人以丙烯酸聚乙二醇酯、甲基丙烯酸缩水甘油酯和含氢硅油为原料,在甲苯中进行硅氢加成反应,合成了可交联、亲水性聚硅氧烷,以提高材料的抗蛋白质吸附性和细菌黏附性。探讨了反应温度、反应时间、反应物配比对含氢硅油的活性氢转化率的影响。结果发现,当催化剂用量为反应物质量的0．004％,含氢硅油、丙烯酸聚乙二醇酯和甲基丙烯酸缩水甘油酯的量之比为1：1．125：0．1时,     

烃羧基硅油

衢州学院的姚方等人以含氢硅油与甲基丙烯酸甲酯为原料、苯为溶剂、氯铂酸为催化剂，通过硅氢加成反应，制得了烃羧酸甲酯硅油；纯化后加入NaOH水溶液进行水解反应，经中和、洗涤、干燥后，得到烃羧基硅油。硅氢加成反应的较佳条件是氯铂酸用量为含氢硅油质量的60×10^-6，甲基丙烯酸甲酯与含氢硅油的量之比为1．4，     

纺织用聚醚改性聚硅氧烷消泡剂的研究

利用低含氢硅油与α-烯丙基甲基封端聚醚的硅氢加成反应,合成一系列以侧基Si-C连接型的EO-PO嵌段聚醚改性聚硅氧烷.研究了其泡沫性能、浊点和表面张力,比较了甲基封端结构与未封端结构在性能上的差异,根据使用性能要求选出适宜的构型,用红外光谱(IR)表征了其结构,经过配方组分优化,研制出纺织整理软片用消泡剂TA-2008,测试结果表明:TA-2008的快速消泡、持久抑泡、稳定性等性能良好.     

我国脂肪酸的生产和应用

简要介绍脂肪酸的分类、原料来源、生产工艺、品种以及用途。并对我国脂肪酸的生产现状进行了分析。重点介绍了脂肪酸在我国橡胶工业中、塑料助剂等领域的应用,脂肪酸甲酯作为表面活性剂在不同领域的广泛应用,最后还简述了癸二酸和改性醇酸树脂应用。     

酸液体系的研究现状分析和现场应用

酸化解堵与压裂改造相比,它具有施工相对简单和成本相对较低等特点,所以酸化解堵是一项各油田广泛使用的油气田增产技术。酸化解堵技术已有将近100历史,现已研制出具有不同特点的酸液体系,如乳化酸、泡沫酸、固体酸、多氢酸等,基本能满足复杂地质条件对酸液的要求。     

油酸的精制研究

油酸酰胺是一种很好的塑料添加剂 ,可用作塑料加工成型时的脱膜剂、润滑剂。油酸的原料来源很广 ,牛油、羊油、猪油等动物油油脂以及大豆油、花生油、棕榈油等植物油脂中都含有大量的油酸。由于油酸的来源和生产方法多种多样 ,因此其所含的脂肪酸种类及含量都不尽相同。除油酸外 ,还有亚油酸、亚麻酸等高不饱和脂肪酸。针对油酸中因含有大量的多不饱和组分如亚油酸、亚麻酸而容易产生氧化泛黄的问题 ,采取了尿素络合法对原料油酸进行精制 ,以减少原料中亚油酸、亚麻酸组分的含量。经气相色谱验证 ,产品达到了应用指标 ,提高了产品的抗氧性。     

The Growth‐Inhibiting Effects of Beef Fatty Acids on MCF‐7 Cells Are Influenced Mostly by the Depot Location and Inconsistently by the Biohydrogenation Intermediate Content

Biohydrogenation intermediates (BHI) including conjugated linoleic acid (CLA) isomers are formed during ruminal biohydrogenation of polyunsaturated fatty acids (PUFA) in ruminants. Although many studies have examined the anticarcinogenic effects of CLA, few studies have reported the anticarcinogenic properties of BHI in their natural form found in dairy and beef fats. The present study compared the growth‐inhibitory effects of fatty acids from beef perirenal fat (PRF) or subcutaneous fat (SCF) with low or high levels of BHI in MCF‐7 human breast cancer cells. Cells were exposed for 72 h to media containing increasing doses (50 to 400 μM) of different beef fat treatments. Fatty‐acid analysis showed that BHI were readily incorporated into cell phospholipids (PL) in a treatment‐dependent manner, but higher BHI in PL did not consistently inhibit growth. Culturing with low‐BHI PRF or high‐BHI PRF did not lead to growth inhibition, but low‐BHI SCF inhibited growth, and inhibition was further increased by high‐BHI SCF. Other classes of fatty acids may, therefore, be interacting with BHI resulting in differential effects on growth inhibition in human breast cancer cells.     

磷钼杂多酸的合成研究

介绍了磷钼杂多酸的合成。通过正交试验探讨了反应物料量比、三氧化钼浓度、反应温度和反应时间对产物产率的影响。结果表明,最适宜的反应条件为:反应物量比n(三氧化钼)∶n(磷酸)=12∶1.0、反应温度t=70℃、反应时间7 h、三氧化钼与水的质量比1∶8。经红外光谱分析及熔点测定确定所得产品为磷钼杂多酸化合物。并以磷钼杂多酸取代硫酸作催化剂制备乙酸乙醋来研究其催化活性,并与硫酸做催化剂进行对比实验收率为70.75%,超过硫酸催化剂水平。     

Fatty Acid Profiles in Sunflower Grains During Storage in Different Environments

This study aimed to evaluate the fatty acid profiles of sunflower oil extracted from hybrid grains produced and stored in different environments. The trials were conducted in Teresina (Piauí), Vilhena (Rondônia), and Jaguariúna (São Paulo) in randomized complete block design with 4 replicates. After harvesting, grains from 1 high oleic and 3 traditional hybrids were packed in kraft paper bags and stored in a covered shed and in a cold chamber up to 12 months. The fatty acid profiles were determined by gas chromatography after 0, 4, 8, and 12 months of storage. Analyses of variance were conducted in a split‐plot design, with hybrids being considered as whole plots and storage times as subplots. Tukey's test was performed to compare hybrids and regression analyses for storage times. The initial fatty acid profile of the grains of the same hybrid varied depending on the production location. The grain storage of high oleic and traditional sunflower hybrids during 12 months in covered shed and in cold chamber resulted in little changes in oil fatty acid profiles, regardless of the initial contents. These changes occurred only for linoleic and palmitic acids.     

Fatty Acid Profiles of Oil Obtained from Mid-Oleic Sunflowers Grown in Tropical Region

This study aimed to verify whether the fatty acid profiles of mid-oleic genotypes grown in the tropical region of Brazil fit the Codex Alimentarius and to examine the possibility of using traditional inbred lines to produce high-oleic hybrids. For this purpose, we assessed the fatty acid profile of six mid-oleic hybrids grown in environments with different minimum temperatures during oil formation in the achenes. The tests were conducted between 2015 and 2017 in an experimentally randomized complete block design with four replications. The oleic, linoleic, palmitic, and stearic acid contents were determined using gas chromatography. The mid-oleic hybrids presented varying levels of fatty acids, with oleic acid ranging between 43.6% and 84.6%, linoleic acid between 8.5% and 45.6%, palmitic acid between 3.9% and 5.7%, and stearic acid between 2.2% and 6.2%. Some of the fatty acid values were outside the ranges established by the CODEX STAN 210-1999 and were characteristic of high-oleic type sunflowers. This finding shows that we can take advantage of the potential of combining traditional inbred lines to produce high-oleic hybrids for faster and more economical breeding programs in these environments.     

Quality of Sunflower Oil Obtained in the Main Producing Region of Brazil: Adherence to the Codex Alimentarius

The objective of this work was to evaluate the quality of the oil extracted from sunflower achenes grown in Campo Novo de Parecis, the main producing region of Brazil, to optimize its use by the processing and food industries. In addition, the fatty acid profiles of the oil were checked for their adherence to the CODEX STAN 210–1999. Traditional and high-oleic genotypes were grown between 2014 and 2017 during trials with a randomized complete block experimental design with four replications. The contents of oleic, linoleic, palmitic, and stearic acids were determined using gas chromatography. The fatty acid profiles of traditional genotypes were observed to be outside the ranges established by the CODEX, with an oleic acid content above 39.4% and linoleic, palmitic, and stearic acid values lower than 48.3%, 2.7%, and 5.0%, respectively, as well as high-oleic sunflower oil with a stearic acid content of less than 2.6%. The availability of this information can, on the one hand, positively impact industries and encourage the use of better quality raw materials that are more technologically and nutritionally adequate. On the other hand, the commercialization of sunflower oil with a fatty acid profile outside the ranges established by CODEX can be difficult, because the contents are out of specification due to the climatic conditions in the cropping region.     

质子酸催化合成α-氯代十二酸工艺研究

采用廉价的浓硫酸为催化剂,氧气为自由基捕集剂,以十二酸为原料,经氯化合成α-氯代十二酸。系统考察了反应温度、催化剂用量、氯气流量、氧氯比、反应时间等因素的影响,得到最佳工艺条件:十二酸20 g,在反应温度135℃、催化剂10%、氯气流量50 mL·min-1、vO2/vCl2=1∶2、反应时间3 h,可实现十二酸基本完全转化,目标产物α-氯代十二酸选择性达到94.5%。     

草酸作助剂磷钨酸催化H2O2氧化环己醇合成己二酸

在无有机溶剂、无相转移催化剂条件下,以草酸作助剂,采用磷钨酸催化过氧化氢氧化环己醇的方法来制备己二酸。考察了磷钨酸用量、反应时间、反应温度、过氧化氢用量及草酸用量对己二酸的分离产率的影响,得到最佳工艺条件,即环己醇10.51 mL、磷钨酸0.6 mmol/L、草酸1.0 mmol/L,H2O2(30%)70 mL,温度85℃、时间8 h,己二酸的最大分离产率为77.83%,纯度为99.9%。