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反应性乳化剂及其乳液聚合 总被引:22,自引:4,他引:18
总结了反应性乳化剂的几种主要类型和结构特征,着重综述了可聚合乳化剂(也称表面活性单体)的乳液聚合规律以及表面活性引发剂在乳液聚合中的应用 相似文献
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如何提高乳胶产品固含量及其性能一直是乳液制备工作所追求的重要目标。乳液聚合中可以使用各种乳化剂,也可不用乳化剂,但都必须使乳胶粒子表面具有亲水性即表面活性,因此,乳液聚合中的原理与技术实际上可以归结为使乳胶粒子表面具有亲水性即表面活性技术。各种研究表明,采用不同乳化剂和表面活性技术所制备的乳胶性能差别很大,合适有效的表面活性技术不仅大幅度提高聚合物乳液的性能,还可以缩短反应时间,简化制备工艺。本文详细评述了近几年来高固含量乳液聚合中常规乳化剂、可聚合乳化剂、复合乳化剂和表面活性单体及其与之相应的表面活性技术的研究现状,并对高固含量乳液乳化剂的发展进行了展望。 相似文献
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反应性乳化剂及其乳液聚合 总被引:4,自引:0,他引:4
本文总结了反应性乳化剂的几种主要类型 ,详细论述了可聚合乳化剂 (也称表面活性单体 )的乳液聚合规律以及表面活性引发剂在乳液聚合中的应用 相似文献
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以醋酸乙烯和少量不饱和二元羧酸单体共聚并醇解,得到醋酸乙烯、乙烯醇和乙烯基不饱和二元羧酸的三元共聚物,即以羧酸改性的聚乙烯醇(PVA)。研究了改性PVA的水溶性和表面活性(水溶液表面张力、乳化力等),探讨了它的结构和性能之间的关系,并制得表面活性优于PVA-KH-20、PVA-GL-03等的改性PVA,可望用作乙烯基单体(特别是醋酸乙烯)乳液聚合的乳化剂或氯乙烯悬浮聚合的分散剂。 相似文献
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研究了十二烷基苯磺酸钠和C12脂肪醇聚氧乙烯(3)醚对活性氧化铝孔结构的影响。实验结果表明,十二烷基苯磺酸钠和C12脂肪醇聚氧乙烯(3)醚能够使氧化铝平均孔径从11.98 nm分别移至6.32 nm和9.42 nm,比表面从193 m2/g分别增至241 m2/g和230 m2/g。这两种表面活性剂之所以能显著影响氧化铝孔分布,主要是因为,以氧原子为极性头的表面活性剂,不仅能够进入拟薄水铝石粒子间隙,而且能够插入拟薄水铝石层间,其氧原子与拟薄水铝石层表面的羟基以及水分子,通过氢键形成一种新的复合氧化铝。在焙烧的过程中,表面活性剂能够减小拟薄水铝石层表面和微孔内壁的应力,避免了层间的坍塌和毛细孔的收缩,从而影响氧化铝孔分布,且极性头小的表面活性剂影响效果优于极性头大的表面活性剂。 相似文献
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V. G. Gaikar S. S. Bodhankar V. Latha 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1996,67(4):329-332
The effect of cationic and anionic surface active additives on the partitioning of proteins has been studied. The surface active agents interact with proteins electrostatically and also hydrophobically. The increased hydrophobicity of the proteins because of association with surfactants is responsible for the changes in the partition coefficients and in some cases for precipitation of the proteins. Specific interactions also exist between mildly surface active amino acids and proteins. 相似文献
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捅要:就几种不同的环保或不环保的(含APEO)非离子表面活性剂对乳液聚合的影响进行一些探讨与研究,寻找APEO的替代品及乳液聚合过程中对乳液稳定性的影响。表面活性剂(特别是非离子型)是乳液聚合中的重要助剂,其性能很大程度上决定了乳液的最终性能:乳液稳定性、乳液粒子粒径大小、成品性能(耐水性、成膜性能、力学性能、粘结性能等)等等,由于传统性能优异的APEO越来越大范围禁用,选择绿色环保的非离子表面活性剂是从事合成乳液的化学专家重要任务。研究结果表明市场上绿色环保的非离子表面活性剂基本可替代APEO,效果与APEO比或稍有不如,也有综合性能较为特出的如SRNIE非离子表面活性剂,明显比APEO优胜。 相似文献
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纳米羟基磷灰石(nano-HAP)的制备工艺在有效控制晶形、尺寸、稳定性等方面尚不成熟,阻碍了它的应用发展。采用化学沉淀法,以Ca(NO3)2.4H2O和(NH4)2HPO4为主要原料合成nano-HAP,在一定工艺条件下通过添加表面活性剂改善制备效果,用XRD、TEM、IR等检测手段表征产物,研究了聚乙二醇-400、聚乙二醇-6000、聚乙烯醇和吐温-80等4种表面活性剂对产物的形貌、粒径、结晶度、分散性等的影响。结果表明:在实验条件下,添加聚乙二醇-400的制备效果最佳,可得平均粒径约为20 nm、结晶度高、稳定性好的高纯nano-HAP针状晶体。 相似文献
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Egbert Meissner Jerzy Myszkowski Jan Szymanowski Rakan Barhoum 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1993,57(1):49-55
Nonionic surfactants having polydisperse polyoxyethylene chains and highly fluorinated hydrophobes were synthesized via a complex reaction route and their adsorption at water/air interfaces studied. They exhibit high surface activity and decrease both effectively and efficiently the surface tension of their aqueous solutions. The effect of the length of the polyoxyethylene chain upon surfactant surface activity is relatively low. Lower values of surface tension, below 30 mN m?1, are obtained for surfactants having a low degree of ethoxylation. Surfactants having two terminal highly fluorinated hydrophobes are less surface active than analogues with one terminal hydrophobe. 相似文献
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Anionic bisphosphodiester gemini surfactants with two different spacer moieties and varying alkyl chain lengths were synthesized and investigated for their surface active properties. The equilibrium and dynamic surface tension studies were carried out using the Wilhelmy plate technique and maximum bubble pressure method respectively. It was found that these gemini surfactants possess lower critical micellar concentration values, and reduce the surface tension to a greater extent in comparison with the conventional analogues. The efficiency of the synthesized gemini surfactants was also evaluated. The results of surface activities obtained were correlated with the structures of gemini surfactants. The dynamic surface tension measurements showed that the geminis with long chains adsorb very slowly at the air/water interface within the time span of measurements. These gemini surfactants showed low foamability. 相似文献
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Eid A. Ismail 《应用聚合物科学杂志》1998,68(9):1531-1536
A novel series of water-soluble polyurethane surfactants has been prepared by the addition polymerization of 2,4 and 2,6-toluene diisocyanate 80 : 20%, respectively (TDI) to polyethylene glycol (PEG) and/or castor oil and ethylene glycol (EG). These water-soluble polyurethane surfactants have been found to exhibit excellent surface active properties including surface tension, foaming and wetting tendency, and formation of stable emulsions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1531–1536, 1998 相似文献