旱冬瓜乙酸乙酯萃取相化学成分研究

对旱冬瓜的化学成分进行了研究,采用硅胶柱层析、重结晶等分离手段进行分离,并用有机波谱学的方法进行结构鉴定。结果得到6个化合物,分别为：香兰素（vanillin,1）、β-谷甾醇（β-sitosterol2,）、胡萝卜苷（daucosterol,3）、β-扶桑甾醇（β-rosasterol4,）、豆甾醇（sterols stigmasterol,5）、没食子酸（Gallic acid6,）。     

Porous composites of hydroxyapatite‐filled poly[ethylene‐co‐(vinyl acetate)] for tissue engineering

A novel porous composite of hydroxyapatite/poly[ethylene‐co‐vinyl acetate)] (HAP/EVA) having better osteointegration was fabricated by gas foaming technique using a non toxic gas blowing agent intended for bone replacement applications. Combined techniques of scanning electronic microscopy (SEM) and X‐ray microcomputed tomography (µCT) analysis showed that the pore size and pore volume of the porous composite decrease with the increase of HAP content. The gravimetric analysis evidenced for good pore interconnectivity within the porous composites. Energy dispersive X‐ray analysis (EDX) studies inveterated the even scattering of Ca ions which in turn indicate the uniform dispersion of HAP particles in the composites. The significant gradation in Ca ion concentration seen in EDX studies is well accordance with the amount of HAP loading in the sample. Mechanical properties of the porous composite having different HAP content were measured to have the compressive strength varying from 1.06 to 2.2 MPa. Non‐cytotoxic character of the material was observed by the cytocompatibility studies. The metabolic activity of L929 cells seeded on the material assessed by [3‐(4,5‐dimethylthiazol)‐2‐yl]‐2,5‐diphenyltertrazolium bromide (MTT) assay was found to be 91.8%. The adhesion and migration of the cells inside the pore walls were visualized by confocal microscopy. Copyright © 2010 Society of Chemical Industry     

Effect of different curing systems on heat shrinkability and mechanical properties of ethylene vinyl acetate/epoxidized natural rubber blends

Ethylene vinyl acetate (EVA)/epoxidized natural rubber (ENR) blends containing 10 and 30 wt % ENR were prepared by using an internal mixer. Five different types of curing systems were employed: dicumyl peroxide (DCP), sulfur (S), phenolic resin (Ph), DCP + S, and DCP + Ph. DCP could crosslink with both EVA and ENR while S and Ph were curing agents for ENR. The DCP system provided the lowest tensile properties and tear strength because of low crosslinking in ENR phase. Addition of sulfur or phenolic resin increased the mechanical properties due to a better vulcanization of the rubber phase. The mechanical properties of the blends decreased with increasing ENR content. The rubber particle size in the blends containing 30% ENR played a more important role in the mechanical properties than the blends containing 10% ENR. ENR particle size did not affect heat shrinkability of EVA and a well vulcanized rubber phase was not required for high heat shrinkage. Furthermore, heat shrinkage of the blends slightly changed as the ENR content increased for all curing systems. With regard to the mechanical properties and heat shrinkability, the most appropriate curing system was DCP + Ph and in the case the 10 wt % ENR content produced a more favorable blend. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

尼龙66/乙烯-醋酸乙烯酯共聚物接枝马来酸酐共混体系的研究(Ⅰ)乙烯-醋酸乙烯酯共聚物熔融接枝马来酸酐的制备与表征

以马来酸酐为单体、过氧化物为引发剂，采用熔融挤出法制备了乙烯-醋酸乙烯酯共聚物接枝马来酸酐(EVA-g-MAH)。重点讨论了不同型号的EVA、过氧化物引发剂品种及用量、单体MAH用量和加工工艺条件等因素时接枝反应的影响。通过化学滴定法和傅立叶红外光谱法(FTlR)证实部分马来酸酐确实以化学键连接到EVA分子链上。与聚乙烯(PE)、聚丙烯(PP)相比，EVA中由于含有醋酸乙烯(VA)基团，极性较大，与MAH的相客性较好，因而在相同的条件下接枝效率也更大；而且VA含量越大，越有利于接枝反应。比较不同的过氧化物引发剂BPO和DCP。发现DCP的引发效果更好。实验结果还表明，在EVA进行接枝反应的同时存在着交联反应，引发剂DCP的用量不宜过高，为得到接枝率适中，交联度很小的接枝产物，还要选择合适的MAH与DCP的用量。     

Ni/PHAC催化甲醇羰基化合成乙酸工艺研究

以自制的酚醛树脂基活性炭(PHAC)负载镍为催化剂、碘甲烷为助催化剂,研究了在连续固定床反应器中催化甲醇碳基化合成乙酸的反应。探讨了反应温度、液体进料空时、甲醇与一氧化碳配比及加水量等反应工艺条件对甲醇羰基化反应及乙酸收率的影响,优化了反应的工艺条件。结果表明：反应工艺条件对甲醇羰基化反应及乙酸的收率影响较大,在系统压力为1．0MPa,反应温度558K,液体进料空时为10gcat．(mo1．h^-1)^-1,V(H20)：V(CH30H)＝3：100,n(CO)：n(CH30H)：n(CH3I)＝80：40：1的条件下乙酸收率最高达到了67．1％,而羰基化产物总收率可以达到79．1％,甲醇转化率可以达到93．8％,羰基化产物总收率和乙酸收率明显高于文献报道的同类催化剂。     

固体超强酸合成乙酸丁酯

本文讨论了固体超强酸催化剂合成乙酸丁酯的方法，比较了各类固体超强酸的优劣，为工业化生产乙酸丁醋筛选超强酸催化剂提供极具价值的参考依据。     

氯化聚氯乙烯合金的制备

利用ACR、CPE和EVA作为加工助剂和抗冲改性剂与CPVC共混。对合金的性能作了测试。并对CPVC加工用的配方和工艺条件进行了探讨。结果表明：ACR(最佳用量为5份)能够改善CPVC的加工性能；CPE(最佳用量为9份)和EVA(最佳用量为5份)能提高合金的韧性。     

乙酸苄酯的合成新工艺研究

报道了合成乙酸苄酯的新工艺 ,以有机溶剂丙酸丁酯作为反应介质 ,三乙胺为催化剂 ,合成了乙酸苄酯。产品收率可达 99 1%,产品纯度 >99 5 %,溶剂可反复回收使用。     

高效导向筛板及填料在醋酸乙烯精馏塔中的应用

对醋酸乙烯 -醋酸甲酯精馏塔进行了技术改造。采用计算机模拟精馏塔的回流比、塔板数、能耗、冷却负荷等 ,优选出最佳方案 ,即采用回流比 15、塔板数 70 ,并应用高效导向筛板塔及填料代替原浮阀塔 ,改造后生产能力、产品质量均得到提高     

水溶液型醋酸钴催化剂的工业运用研究

本文介绍了水溶液型醋酸钴催化剂在仪化年产33万t的PTA装置上的试用情况,试用过程中发现催化剂中黑色沉淀物可以抑制PX氧化主反应,促进燃烧副反应,影响产品质量和装置正常操作。