End-capped polystyrene with 8-hydroxyquinoline group by ATRP method

8-Hydroxyqunioline end-capped polystyrene was prepared through atom transfer free radical polymerization (ATRP) with 8-(5-chloromethyl) quinolyl acetate as initiator. The results indicated that this polymerization is a first order reaction with respect to monomer conversion. The molecular weight increased linearly with monomer consumption and very narrow distribution of molecular weight was obtained (polydispersity index less than 1.2). The FT-IR and NMR results show that the 8-hydroxyquinloine group was chemically bonded to the polymer end and there is nearly one 8-hydroxyquinoline group in per polymer chain. All those data show that polymerization of styrene at such conditions displayed living characters. The polymer with 8-hydroxyqquinoline end group reacted with triethylaluminum to form polymeric light-emitting complex and single layer LED was prepared by common spin-coating method. The peak wavelength of LED based on synthesized polymeric complex was around 570 nm.     

纤维素醚的特点、制备及在工业中的应用

综述了纤维素醚的种类、制备方法、性能和特点,以及纤维素醚在石油、建筑、造纸、纺织、医药、食品、光电材料及日化工业中的应用,介绍了一些具有发展前景的纤维素醚类衍生物的新品种并展望其应用前景。     

纤维素/NMMO·H_2O溶液体系流变性能的研究

利用 Brookfield DV-Ⅱ型粘度计对纤维素/NMMO·H2O 溶液体系的流变性能进行了研究,讨论了温度、纤维素浓度、浆粕聚合度及添加剂等对溶液粘度的影响。结果表明,纤维素/NMMO·H2O 溶液的流动活化能较低,因此其表观粘度随温度的变化不大;纤维素浓度和浆粕聚合度的增加都可使溶液粘度增大,但纤维素浓度对溶液粘度的影响更显著;抗氧化剂没食子酸丙酯(GPE)的加入减缓了加热时溶液粘度的下降,降低了纤维素的氧化降解;二甲亚砜(DMSO)的加入可有效地控制溶液粘度,改善溶液的加工性能。     

Structure and properties of regenerated cellulose films coated with polyurethane–nitrolignin graft‐IPNs coating

A regenerated cellulose film (RC) was coated with a graft‐IPNs coating, which was composed of castor oil‐based polyurethane and 2.8 wt % nitrolignin (NL), to obtain water‐resistant films. The effects of NCO/OH molar ratio and different polyols, such as 1,4‐butanediol (BDO) and trimethanol propane (TMP), on the structure and properties of the coated RC films were investigated. With an increase of the NCO/OH molar ratio, the tensile strength of the coated films increased, but the water resistivity and size contraction hardly changed. The coated films with TMP exhibited the higher breaking elongation at 1.5 of the NCO/OH molar ratio, while those with BDO have more excellent tensile strength, water resistivity, and dimensional stability. The coated films with the graft‐IPNs coating exhibited superior water resistivity and dimensional stability. The light transmittance of the coated films was more excellent than that of the RC film. Moreover, the results from the IR and electron probe microanalysis (EPMA) showed that the chemical bonding occurred between cellulose and coating, and the introduction of NL plays an important role in the enhancement of the interface adhesion of the coated films. Atomic force microscopy (AFM) depicted the flat and dense surface of the coated films, which restricted the water vapor penetration and the size contraction, resulting in the enhancement of water resistivity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1799–1806, 2002     

固体超强酸S_2O_8~(2-)/Fe_2O_3—CoO催化合成乙酸异戊酯

制备固体超强酸催化剂S2O82-/Fe2O3—CoO,并用于乙酸异戊酯合成反应。用该催化剂通过正交试验合成乙酸异戊酯的最佳条件为:醇酸物质的量比为1.5,催化剂用量为0.8 g(以0.2 mol乙酸为准),带水剂用量为10 mL,反应时间为2.5 h,其酯化率可达98%以上。     

羧甲基纤维素阳离子化衍生物的研究现状

羧甲基纤维素阳离子化改性是制备性能优良的天然两性高分子的重要方法之一。文章综述了迄今为止羧甲基纤维素阳离子化改性所用的阳离子单体的主要类型及其接枝的若干主要途径,其中包括自由基型接枝共聚、高分子侧基反应、聚合后功能化等三大类。     

无机物——聚醋酸乙烯复合乳液粒子结构及主要性能

本文对均聚醋酸乙烯乳液及其与无机物的混合物,无机物——聚醋酸乙烯复合乳液的粒子结构进行了比较,阐述了复合乳液的主要性能。     

Catalytic hydrogenation of nitrile rubber using palladium and ruthenium complexes

The catalytic hydrogenation of acrylonitrile‐butadiene copolymer (nitrile rubber, NBR) using Pd(OAc)₂ or RuCl₂(PPh₃)₃ catalysts has been investigated in order to produce a totally saturated nitrile rubber. The hydrogenation of NBR is effective with both catalysts and achieved total conversion under the appropriate reaction conditions. In the case of palladium the effects of reaction parameters such as reaction temperature, pressure, time, catalyst concentration, and NBR concentration have been investigated. Even though both ruthenium‐ and palladium‐based catalysts are effective in the production of HNBR, the former requires harsh reaction conditions and has the drawback of gel formation under high conversion, motivating the migration to RuCl₂ (PPh₃)₃ as an alternative catalyst. The degree of hydrogenation was determined by IR and NMR spectroscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

采用变压精馏回收共沸剂的正丙醇-水共沸精馏模拟研究

本文研究了一种分离正丙醇-水的新型共沸精馏工艺,通过变压精馏的方法对夹带剂乙酸乙酯进行回收。本研究采用Aspen—Plus软件中的RADFRAC精馏模块,以NRTL活度系数方程和Hayden-O'connell逸度方程为热力学模型对本工艺流程进行模拟,讨论了塔板数、进料位置、进料量、回流比和进料温度等参数对产物精馏和共沸剂回收的分离效果的影响,优化得出最佳工艺参数。结果表明,当精馏塔的塔板数为40块,进料位置为34板,回流比为8,夹带剂与进料比为0.9:常压回收塔的塔板数为20块,进料位置为4板,回流比为0.1,减压回收塔和常压回收塔的压力分别设定为0.2 aim和1 atm时,产物正丙醇的纯度为99.22 mol%,回收的共沸剂纯度达到99.87 mo1%,本文对正丙醇的工业生产具有一定指导意义。     

PE-LLD／EVA／Mg（OH）2／复合阻燃剂高效无卤阻燃体系的研究

采用线形低密度聚乙烯/乙烯-醋酸乙烯共聚物作为复合材料主体,表面处理过的氢氧化镁(Mg(OH)2)为主阻燃剂,以微胶囊化红磷和自制硅类阻燃剂为核心的复合阻燃剂为阻燃增效剂,重点探讨了Mg(OH)2和复合阻燃剂的阻燃效果。结果表明,Mg(OH)2与复合阻燃剂并用具有良好的协同效应,当Mg(OH)2用量40份,复合阻燃剂5～7份时,可获得较高的氧指数,垂直燃烧试验通过FV0级,且材料抗静电能力提高,力学性能、加工性能较好。