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由聚马来酸酐和十八醇合成了一系列不同羧酯比的聚马来酸十八醇酯,并以其为成膜材料,CdCl2水溶液为亚相制备了一系列聚马来酸十八醇酯镉盐LB膜,借助小角X射线衍射和红外吸收光谱表征了成膜条件及羧酯比对CdPMA膜有序结构的影响。在较高膜压和快速提拉条件下,低羧酯比的CdPMA可得到有序性很高的Y-型LB多层膜;高羧酯比的CdPMA得不到高有序性的LB多层膜。 相似文献
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《高分子学报》2015,(1)
采用稀土三元催化剂制备了二氧化碳-环氧丙烷-马来酸酐三元共聚物(PPCMA).用红外和核磁谱图确定了PPCMA的结构及马来酸酐单元的含量,3 wt%马来酸酐投料量的PPCMA(共聚物中马来酸酐单元含量4.1%)的玻璃化转变温度(Tg)和起始热分解温度(Td-5%)分别为13.4℃和217℃,拉伸强度为2.88 MPa,断裂伸长率为1669%,与二氧化碳-环氧丙烷共聚物(PPC)相比,引入少量马来酸酐的PPCMA有望成为一种韧性材料,并可对PPC和聚3-羟基丁酸酯(PHB)共混体系进行改性.当在PPC/PHB共混体系中添加10 wt%的PPCMA时,所得共混材料的拉伸强度为18.2 MPa,断裂伸长率则提高到85%,较没有添加PPCMA的样品提高了4.25倍,因此PPCMA的加入能有效提高PPC/PHB共混体系的韧性,改善PPC/PHB共混体系的力学性能.偏光显微镜的研究表明PPC/PHB共混体系加入PPCMA后,很快形成大量尺寸小的PHB球晶,且结晶速度大幅度提高,因此PPCMA在一定意义上可视为一种特殊的“成核剂”. 相似文献
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目前聚羧酸减水剂大多由甲基丙烯酸合成,而马来酸酐因其结构对称、活性较低等特点而合成工艺简单、易于控制。本文研究以马来酸酐、甲氧基聚乙二醇、乙烯基磺酸钠、甲基丙烯酸为原料采用先酯化再共聚的方法合成出了含有羧酸基、磺酸基、聚氧乙烯基的马来酸酐类聚羧酸减水剂。酯化反应是极其关键的一步,通过研究表明马来酸酐甲氧基聚乙二醇单酯最佳合成条件为:酸醇比为1.15:1、催化剂用量为MPEG质量的6%,、反应时间4h,反应温度为110℃;马来酸酐聚羧酸减水剂的最佳合成配比为n(MPEG-MA):n(SVS):n(MAA)=1:0.75:5。马来酸酐聚羧酸减水剂最佳掺量为0.5%,与市场上的减水剂最佳掺量时的效果相当。 相似文献
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采用化学气相沉积聚合(CVDP)法制备聚对亚苯基二亚甲基(PPX),再通过与酸酐的化学表面反应将丁酸酰基和马来酰基引入PPX薄膜的表面,制得表面带活性取代基的PPX.改性后的薄膜表面粗糙度略有增加,但仍旧维持在10nm以内.改性后的薄膜水接触角减小,减小幅度达到十几度,表面亲水性大幅度提高.丁二酸酐表面改性后薄膜的抗化学氧化时间不变,马来酸酐表面改性后薄膜的抗氧化时间略有下降,但抗氧化时间都大于30h,仍具有优异的抗化学氧化性能.丁酸酰基和马来酰基取代PPX肝素化反应后膜中的肝素含量在7μg/cm2左右,肝素化后薄膜的抗凝血性能得到明显提高. 相似文献
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利用原子转移自由基聚合法(ATRP)合成三嵌段两亲性聚乳酸共聚物聚乙烯吡咯烷酮-聚乳酸-聚乙烯吡咯烷酮(PVP-b-PLA b-PVP),然后将其与聚偏氟乙烯(PVDF)进行其混,制备PVP-b-PLA-b-PVP/PVDF共混膜.结果表明:PVDF膜表面致密,膜断面中指状大孔和海绵状孔同时存在,而共混膜表面多孔,指状大孔贯穿整个断面;与PVDF膜相比,共混膜的孔隙率和孔径增大,水通量提高了158.87%,接触角下降了16.70%,抗污染指标下降了64.7%. 相似文献
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Pt/CdS光催化剂表面修饰和表面结构 总被引:1,自引:0,他引:1
Pt/CdS光催化剂表面修饰和表面结构张虎勤陈开勋*金振声(西北大学化工系西安710069)(中国科学院兰州化学物理研究所兰州)关键词光催化剂,半导体,表面组成,表面修饰1996-05-20收稿,1996-09-28修回近年来对在Pt/CdS催化剂上... 相似文献
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表面等离子体子共振生物传感器用于乙肝表面抗原的测定 总被引:5,自引:1,他引:5
运用自行研制的表面等离子体子共振(SPR)生物传感器,采用自组装成膜技 术并以戊二醛作偶联剂,在传感片表面修饰HBsAg单克隆抗体,将其用于乙肝表面 抗原(HBsAg)的检测。实验结果表明SPR生物传感器对HBsAg的检出限为0.06ng/mL 。与传统的酶联免疫吸附试验(ELISA)相比,SPR生物传感器的检出灵敏度明显高 于ELISA法。用该SPR生物传感器对HBsAg质控血清与纯化的HBsAg溶液进行比较检测 ,结果表明该SPR生物传感器对HBsAg具有好的特异选择性。 相似文献
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Hiroyuki Ohshima 《Journal of colloid and interface science》1998,200(2):291
An accurate analytic expression of the surface charge density/surface potential relationship for an infinitely long cylindrical colloidal particle in a solution of general electrolytes is derived from an approximate solution to the nonlinear cylindrical Poisson– Boltzmann equation. The mathematical procedure is based on a method developed previously by Ohshima, Healy, and White for the case of a sphere (J. Colloid Interface Sci.90, 17 (1982)). Comparison is made with exact numerical results. Accurate expressions for the potential distribution around a cylinder and the effective surface potential of a cylinder are also derived. Finally, expressions for the double-layer interaction energy and force between two cylinders at large separations are derived on the basis of the method of Brenner and Parsegian (Biophys. J.14, 327 (1974)). 相似文献
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胶体颗粒的表面电荷密度和表面电位之间的关系是颗粒表面的基本性质之一.要确定这个关系,需要解Poisson-Boltzmann(PB)方程,求出颗粒外的电位分布.然而对于球形颗粒,PB方程却没有解析解.Loeb等,求出了数值解,近似解析表达式虽然很多,也比较复杂, 相似文献
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Nobuyuki Furukawa Yasuharu Yamada Masaya Furukawa Masatoshi Yuasa Yoshiharu Kimura 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2239-2251
Two series of polysiloxane-block-polyimides were synthesized by the method of solution imidization of the polyamic acids prepared from the dianhydride/diamine combinations of 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA)/2,2-bis[4-(4-aminophenoxy) phenyl] propane (BAPP) (Series A) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA)/bis[4-(3-aminophenoxy) phenyl] sulfone (BAPSM) (Series B) with three kinds of w-diamino-poly(dimethylsiloxane) with different number-average molecular weight added as a part of diamine. These polysiloxane-block-polyimides, having various compositions and chain lengths of the polysiloxane segments, were subjected to solution casting to prepare their films, and their surface and interface properties were analyzed by contact angle, XPS, AFM, and SEM. It was found that the surface tension and surface topography were greatly influenced by the composition and molecular weight of the polysiloxane segments because of their surface enrichment, which was affected by the environment and substrate with which the copolyimides had contacted. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2239–2251, 1997 相似文献
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Wei‐Yu Chen Yuhui Lin Kumari P. Pramoda K. X. Ma T. S. Chung 《Journal of Polymer Science.Polymer Physics》2000,38(1):138-147
By using the two‐liquid geometric method and the three‐liquid acid‐base method, we are the first to determine the surface tensions of ladderlike polyepoxysiloxanes by the measurement of contact angles on thin films. Three kinds of ladderlike polymers have been synthesized: A C (which has the alkyl group and the epoxy group graft to the ladderlike polysilsesquioxane chain), A C P (which has the alkyl group, phenyl group, and epoxy group graft to the ladderlike chain), and A P (which has the phenyl group and epoxy group in the ladderlike side chain). The results showed that when different liquids and different theories are chosen to determine the surface energies, there are some minor differences in the values but a similar trend is still exhibited. The surface energies of these three polymers are in the following order of γSA C < γSA C P < γSA P. Interestingly, the surface energy increases for these polymers are mainly from the nonpolar part of the polyepoxysiloxanes. XPS surface analysis indicated that the Si and O ratios of these polymers at the air‐polymer interface were in the order of A C > A C P > A P, suggesting Si atoms were more likely to migrate to the polymer surface and the bulky effect of the phenyl groups could also interfere with the migration of the Si atoms. As a result, Si and O ratio at the interface determines the order of apparent surface energy for these three polymers. Experimental data also reflect that there are differences between the ladderlike polyepoxysiloxanes and the commercially available linear polysiloxanes. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 138–147, 2000 相似文献
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含氟聚合物材料具有优异的热稳定性、极低的表面能、强化学稳定性和生物相容性等,在功能涂料、织物整理、微电子、汽车以及航空航天等领域具有很好的应用前景。本文综述了侧基含氟聚合物的主链、全氟烷基链、主链与全氟烷基链段间连接基团的结构对聚合物表面性能的影响,并总结了环境友好型低表面能侧基含氟聚合物的研究进展。 相似文献