共查询到19条相似文献,搜索用时 125 毫秒
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有机硅改性丙烯酸酯共聚乳液的合成及表征 总被引:1,自引:0,他引:1
采用间歇和种子半连续乳液聚合方法合成有机硅改性丙烯酸酯(硅丙)共聚乳液,用激光粒度仪、透射电子显微镜、差示扫描量热仪、表面张力仪等分析了硅丙共聚乳液和涂层的性能。采用种子半连续乳液聚合和间歇乳液聚合均可得到具有核-壳结构的硅丙共聚乳液。半连续乳液聚合得到的硅丙共聚乳液的粒径较小,粒径分布窄;采用半连续滴加纯丙烯酸酯单体和滴加单体预乳液对共聚乳胶粒子的平均粒径及粒径分布、形态影响不大。采用间歇乳液聚合可使有机硅单体的开环聚合和丙烯酸酯单体的自由基聚合同时进行,获得的硅丙乳液稳定性好,但聚合转化率偏低,乳胶粒子粒径较大,粒径分布较宽。硅丙共聚乳液胶膜的吸水率小于纯丙烯酸酯聚合物乳液胶膜,并随有机硅共聚率的增加而降低;硅丙乳液胶膜的接触角接近有机硅接触角。硅丙共聚乳液涂层整理的织物手感优异,但涂层牢度小于纯丙乳液整理剂。 相似文献
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烷羟基聚醚型有机硅/水性聚氨酯嵌段共聚物的制备及表征 总被引:2,自引:0,他引:2
以聚醚、二羟甲基丙酸(DMPA)、异佛尔酮二异氰酸酯(IPDI)为主要原料,采用自乳化法合成了水性聚氨酯乳液,并使用一种三官能度烷羟基聚醚型有机硅为主要原料,制备出少量交联的、耐水性优异的嵌段型水性有机硅聚氨酯。考察了聚醚型有机硅用量对乳液稳定性、乳胶膜耐水性及拉伸性能的影响。结果表明,乳液的稳定性良好,乳胶膜的耐水性明显提高,拉伸强度增加;当有机硅在预聚体中的质量分数为1.4%时,乳胶膜的耐水性、拉伸性能最佳,且乳胶膜的柔顺性明显。 相似文献
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The breakup of non-Newtonian emulsion jets into drops was experimentally studied by ejecting both O/W and W/O emulsions vertically downward into stagnant air through nozzles. Breakup lengths of non-Newtonian emulsion jets were found to be almost equivalent to those of Newtonian jets. Experimental breakup data establish that the static surface tension of the oil phase can be used as the surface tension of W/O emulsion jets, whereas the dynamic surface tension of aqueous surfactant solutions is used as that of O/W emulsion jets. Diameters of drops formed from non-Newtonian emulsion jets are in good agreement with the prediction from the stability theory previously developed by the authors. When the rheological index in a power law model is appreciably smaller than unity and the Ohnesorge number is significantly large, however, drop sizes are larger than the prediction because of the profile relaxation in jets. The critical velocity of emulsion jets, either O/W or W/O emulsion, is significantly lower than that of homogeneous Newtonian jets. 相似文献
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PHMS/VAc复合乳液的研究 总被引:1,自引:1,他引:0
分别采用一次加料法和单体连续滴加法制备了含氢聚甲基硅氧烷/醋酸乙烯酯/羟甲基丙烯酰胺复合乳液,讨论了这两种聚合方法对乳液性能、粒径大小及转化率的影响,同时也考察了乳化剂配比及用量对乳液各项性能的影响。结果表明:在单体连续滴加法下,采用非离子型和阴离子型复合乳化剂可制得较为稳定的乳液。 相似文献
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以月桂醛与琥珀酸酐接枝改性具有三股螺旋结构的天然胶原,得到了一种保留了天然胶原结构的生物表面活性剂(胶原基生物表面活性剂,简称BCB)。研究了BCB的基本表面活性,结果表明,BCB具有较好的泡沫膨胀和泡沫稳定性,其乳化活性(284.08 m2/g)与天然胶原(32.23 m2/g)相比有显著的提高,乳化稳定性和吸油能力也有所提升。BCB的润湿能力随着其浓度的增加而提高,表面张力随存放时间的延长而降低,在质量浓度为5.0×10-3g/L时,表面张力在3 000 s时达到平衡,为52.58 m N/m。研究表明,BCB和天然胶原的乳液类型均为O/W型。 相似文献
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含沥青质模拟油/水乳状液稳定性与界面性质关系Ⅰ界面张力和Zeta电位的影响 总被引:1,自引:0,他引:1
采用近红外稳定性分析仪研究了水包沥青质模拟油型乳状液的稳定性。考察了两种表面活性剂十二烷基硫酸钠(SDS)和十二烷基苯磺酸钠(SDBS)、沥青质质量浓度以及盐对乳状液稳定性的影响,探讨了油水界面张力及油珠表面的Zeta电位与乳状液稳定性的关系。结果表明,SDBS稳定的乳状液要比SDS稳定;在所考察的条件范围内,沥青质质量浓度越高,乳状液越不稳定,盐能增强乳状液的稳定性。油水界面张力的降低有利于水包油乳状液的稳定,而Zeta电位不是影响乳状液稳定性的主要因素。 相似文献
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EVA改进聚醋酸乙烯乳液粘合剂性能的研究 总被引:6,自引:1,他引:6
本研究采用EVA乳液作为种子进行聚合制备改性聚醋酸乙烯乳液粘合剂。讨论了EVA乳液的用量对聚合物的耐寒性、表面张力的影响。同时,对聚合温度、搅拌速度、引发剂用量、聚合保温时间等进行了选择。改性后的白胶粘合剂具有多次循环的冻融稳定性,且对低表面能材料的粘接强度明显高于通用白胶 相似文献
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Polymeric emulsifiers based on glycerol and oleic acid were developed and their properties evaluated in palm oil and water solutions. Developed polymeric emulsifiers were polyglycerol-esters. Polymerization degree of polyglycerol-esters at different dosages (from 0.2 to 3% w/v) had a significant effect over emulsion stability, water surface tension, droplet size, and viscosity. Polyglycerol-ester with highest polymerization degree behaved more efficiently as emulsifier. A dosage of 0.5% w/v was required to maintain emulsion stability for a half-life period of 872 min (~14.5 h); which, is 5.6 and 3.6-fold longer stability than with the other two polyglycerol-esters developed. When dosage increased to 3% w/v, the emulsion stability also increased to 3792 min (~2.6 days). Nevertheless, surfactants with lower polymerization degree and molecular weight did not behave the same way. Emulsifier with highest polymerization degree reduced water surface tension by 70% and the mean particle diameter decreased when emulsifier polymerization degree increased. For the viscosity parameter, there were two interesting regions: for shear rates up to 1 s−1 the emulsion behaved as Non-Newtonian fluid type Shear-thinning; while, higher shear rates, the viscosity exhibited a Newtonian profile. 相似文献