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N,N-二甲基对甲基苯胺(简称DMT)是丙烯酸酯类聚合反应中的一种促进剂。在快速自凝齿科材料、制模材料和丙烯酸酯类厌氧粘合剂的生产中都有广泛的应用。 DMT可用多种方法会成,一种较常用的合成方法是镍铝合金还原法,是从对-二甲氨基苯甲醛开始,在氢氧化钠的水-乙醇溶液中,加入镍铝合金粉把醛基还原为甲基,但此法成本太高,反应完后留下大量的固体镍泥,回收很麻烦。 相似文献
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“甲基硫氧嘧啶”是一种甲状腺抑制剂,能抑制甲状腺机能,缓慢新陈代谢速度,显著增加体重。用于猪的催肥,效果显著。为市售“肥猪粉”、“肥猪片”的主要有效成分。甲基硫氧嘧啶的制造方法很多。上海新桥农药厂是用乙酰乙酸乙酯和硫脲缩合制得的,但成本高,得率低,原料不易得到。华东师范大学介绍了金属钠法,此 相似文献
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N,N-二甲基对甲基苯胺(DMT)是一个典型的电子给体,可以和多种电子受体形成称之为CCT(Contact Charge Transfer)的络合物。在光照条件下,这种络合物可以生成离子自由基,从而引起一系列反应。 相似文献
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N-甲基吗啉的合成 总被引:3,自引:0,他引:3
N 甲基吗啉是一种杂环叔胺 ,具有醚和胺基的性质 ,广泛应用于杀虫剂、杀菌剂、植物生长调节剂等农药化合物的合成 ,也用于表面活性剂、润滑油冷却剂、金属防锈剂、纤维处理剂等精细化工产品的合成。N 甲基吗啉有 6种合成方法[1~ 3] ,其中以吗啉为原料的合成路线 ,原料来源方便 ,反应条件缓和 ,环境污染较小 ,对生产设备要求较低 ,易于工业化生产。前文[4] 曾报道以吗啉、多聚甲醛和次亚磷酸钠为原料合成N 甲基吗啉 ,文献 [5 ]以吗啉为原料 ,氢氧化钠水溶液为溶剂 ,一氯甲烷为烷基化试剂 ,合成了N 甲基吗啉 ,收率为 43 7%。本文根据正交实… 相似文献
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Jun Zhou Yong-zhi Qiu Xiao-peng Zang Chang-wang Pan Qiang Chen Jian Shen Si-cong Lin 《高分子科学》2005,23(1)
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility. 相似文献
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Youling Yuan Jun Zhang Fei Ai Jiang Yuan Jun Zhou Jian Shen Sicong Lin 《Colloids and surfaces. B, Biointerfaces》2003,29(4):247-256
Surface modification of segmented poly(ether urethane) (SPEU) by graft copolymerization with N,N′-dimethyl-N-methacryloyloxyethyl-N-(3-sulfopropyl) ammonium (DMMSA), a zwitterionic sulfobetaine structure, was conducted. A simple two-step procedure for grafting of DMMSA onto the surface of SPEU film was used. The surface was first treated with ozone to introduce active hydroperoxide groups. The active surface was then exposed to the DMMSA solution in the sealed tube. Grafted SPEU film was characterized by ATR–FTIR, XPS and contact angle measurement. ATR–FTIR and XPS investigations confirmed the graft copolymerization. The monomer concentration, copolymerization temperature and time were varied to maximize the efficiency of DMMSA grafting. The equilibrium water content (EWC) and contact angle measurements showed that the hydrophilicity of the film had been greatly improved. The blood compatibility of the grafted films was evaluated by platelet adhesion in platelet rich plasma (PRP), deposits in blood control and protein adsorption in bovine fibrinogen using SPEU film as the control. No platelet adhesion and no thrombus were observed for the grafted films incubated in PRP for 300 min and in blood for 120 min, respectively. The protein adsorption was reduced on the grafted films after incubation in bovine fibrinogen for 120 min. These results proved that improved blood compatibility was obtained by grafting this new zwitterionic sulfobetaine structure monomer onto SPEU film. 相似文献
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JunZhou Yong-zhiQiu Xiao-pengZang Chang-wangPan QiangChen JianShen Si-congLin 《高分子科学》2005,(1):93-102
N,N-dimethyl-N-methacryloyloxyethyl-N-carboxyethyl ammonium (DMMCA) was graft-copolymerized onto the surface of segmented poly(ether urethane) (SPEU) and PE film. The carboxybetaine structure on SPEU and PE film surfaces was confirmed by ATR-FTIR, XPS and water contact angle measurements. Through the experiments with platelet adhesion and protein adhesion assay in vitro, the two materials studied, including poly-DMMCA gel, all show excellent nonthrombogenicity. This confirms once again that the zwitterionic molecular structure on the surfaces of materials is essential for improving their nonthrombogenicity and biocompatibility. 相似文献
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本文主要研究了在溶液聚合中,用两种加料方式对嵌段聚醚氨酯(SPEU)本体形态结构的影响。由透射电镜观察的结果发现,在预聚反应过程中采用两种加料方式,其最终聚合产物(SPEU)都具有明显的两相结构;加料方式不同主要影响SPEU中分散相的形态和其内的聚集态结构:(1)采用将端羟基的聚四次甲基醚(PTMEG)溶液滴加到4,4′-二苯基甲烷二异氰酸酯(MDI)的溶液中,俟反应完成后再滴加入扩链剂(Extender)的加料方式所制得的SPEU其分散相在形态上呈现为小棒条状,这种分散微区的宽度一般在10—60nm范围内,从选区电子衍射结果证明这种微区的结构是结晶的。(2)而采用将MDI的溶液滴加到PTMEG溶液中,俟反应完成后再滴加Extender的加料方式所制备的SPEU其分散相在形态上呈现为球形,它们的直径多在100至300nm范围内,由电子衍射证明这种分散微区的结构是无定形的。 相似文献
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甲基丙烯酸聚乙二醇单甲醚酯在聚(醚-氨酯)表面的臭氧化接枝 总被引:5,自引:1,他引:5
甲基丙烯酸聚乙二醇单甲醚酯在聚(醚 氨酯)表面的臭氧化接枝王晨晖王安锋车波周彩华苏琳丽林思聪(南京大学高分子科学与工程系生物材料分子工程与控制释放分子工程室南京210093)王炳坤(南京大学环境科学系南京210093)关键词臭氧化,表面接枝,大... 相似文献
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抗凝血聚氨酯材料的研究进展 总被引:7,自引:0,他引:7
聚氨酯由于其优良的抗凝血性能和良好的物理机械性能而成为目前研究和应用最广的一种生物医用高分子材料。本文就嵌段型聚氨酯、拦枝型聚氨酯、离子型聚氨酯及其它具有良好发展前景的聚氨酯抗凝血材料的研究进展作扼要综述。 相似文献
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无光敏剂光引发亲水性单体在嵌段聚醚氨酯膜上接枝聚合的研究 总被引:3,自引:0,他引:3
<正> 嵌段聚醚氨酯(SPEU)是一类应用广泛的医用高分子材料。用亲水性单体进行表面接枝改性,已有不少研究,接枝聚合方法有铈盐引发、辐射引发以及光敏引发等。 本文研究一种新的接枝方法,不加光敏剂,用紫外光照射,直接引发亲水性单体接枝于SPEU膜上、接枝的单体有丙烯酰胺(AAM)与N,N-二甲基丙烯酰胺(DMAA),从接枝前后膜的性能变化可以证实接枝反应的发生。文中研究了反应条件与单体结构对接枝率的影响,并通过模型化合物,对接枝部位进行了研究。 相似文献