共查询到19条相似文献,搜索用时 93 毫秒
1.
2.
高固含量苯丙微乳液聚合的研究 总被引:2,自引:0,他引:2
以阴/非离子型乳化剂作为复合乳化剂体系,进行高固含量St-BA微乳液聚合的研究。获得了固含量达34%,而乳化剂总用量为3.0%、乳液粒径为38.2nm的聚合物微乳液。讨论了聚合方法、乳化剂、反应温度、单体滴加速度、搅拌速率等因素对微乳液聚合的影响。 相似文献
3.
一、前言乳液聚合是制备高聚物的一种比较理想的方法,其主要优点是:(1)以较高的聚合速度获得高分子量的聚合物;(2)在较低的温度下进行反应,聚合热易扩散,整个聚合过程容易控制;(3)用水作介质,既便宜又无污染。因此在塑料、橡胶、涂料、粘合剂的制造中,常采用乳液聚合的方法。乳液聚合是指在机械搅拌或剧烈振荡下,用乳化剂使单体分散在水中进行聚合。乳液聚合体系的组成比较复杂。尽管各组分对乳液聚合都有影响,但乳化剂的影响是重要的,也是多方面的。首 相似文献
4.
5.
6.
高固含量苯乙烯/丙烯酸酯微乳液聚合的研究 总被引:3,自引:0,他引:3
李学军 《精细与专用化学品》2004,12(9):9-11,15
以阴 /非离子型及反应型乳化剂作为复合乳化剂体系 ,以苯乙烯、甲基丙烯酸甲酯、丙烯酸丁酯为主要单体进行高固含量苯乙烯 /丙烯酸酯微乳液聚合研究 ,获得了固含量达 4 0 %、乳化剂总用量为 3 0 %、乳液粒径为37 0nm的聚合物微乳液。讨论了聚合方法、乳化剂、反应温度、单体滴加速度、搅拌强度等因素对微乳液聚合的影响。 相似文献
7.
8.
有机硅-丙烯酸酯乳液聚合稳定性研究 总被引:8,自引:0,他引:8
采用种子乳液聚合工艺,以过硫酸铵为引发剂、十二烷基二苯醚二磺酸钠(DOWFAX2A1)/辛基酚聚氧乙烯(40)醚(TRIONX-405)为复合乳化剂合成了乙烯基 三(2 甲氧基乙氧基)硅烷(A-172)改性丙烯酸酯聚合物。研究了单体加入方式、乳化剂用量、聚合温度、pH值等对聚合稳定性的影响。结果表明,当总乳化剂质量分数为3 0%、聚合温度为75~80℃、pH=6 5~7 5时,采用净单体滴加法制备聚合物的聚合过程稳定性较好;增加A-172用量,聚合稳定性降低。 相似文献
9.
采用半连续种子乳液聚合工艺,在可聚合乳化剂十六烷基烯丙基琥珀酸双酯磺酸钠(Ⅰ)和辛基酚聚氧乙烯醚烯丙基琥珀酸双酯磺酸钠(Ⅱ)存在下,合成了聚丙烯酸酯纳米乳液,探讨了可聚合乳化剂种类及用量、聚合温度、引发剂用量、聚合时间对丙烯酸酯乳液聚合及性能的影响,通过FTIR、TEM和DSC对聚合产物进行了表征分析。结果表明,可聚合乳化剂参与了与丙烯酸酯的共聚反应,所得聚合物乳胶膜的玻璃化温度为23.5℃;与传统乳化剂十二烷基硫酸钠(SDS)相比,可聚合乳化剂可提高乳胶膜的耐水性;当m(Ⅰ)∶m(Ⅱ)=1∶2,乳化剂质量分数2%,聚合温度85℃,引发剂质量分数0.5%,聚合时间2 h时,所得乳液的固体分质量分数为32.70%,平均粒径72.3 nm,分布指数0.143,吸水率4.57%。 相似文献
10.
11.
In this article, we report on an approach of using an emulsion polymerized polymer in preparing organic–inorganic nanocomposites through a sol–gel technique. By mixing a polymer emulsion with prehydrolyzed tetraethoxysilane transparent poly(butyl methacrylate)/SiO2, nanocomposites were prepared as shown by TEM. AFM, FTIR, and XPS results show that there is a strong interaction between polymer latex particles and the SiO2 network. Comparison of the emulsion method with a traditional solution method shows that nanocomposites can be prepared by both methods, but there is some difference in their morphology and properties. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 446–454, 2002 相似文献
12.
硅丙乳液/水泥基复合防水粘接涂层的研制 总被引:1,自引:0,他引:1
以丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯酸(AA)、有机硅氧烷(A-174)和阴/非离子型乳化剂等为主要原料,制备硅丙乳液;然后以此为基体、以普通硅酸盐水泥和填料等为固体料,制备出一种耐水性、耐碱性、耐热性和柔弹性等俱佳的聚合物/水泥基复合防水粘接涂层。通过单因素试验法优选出制备该粘接涂层的较佳工艺条件。结果表明:当阴/非离子型乳化剂的质量比为1∶1、w(A-174)=1.5%、w(AA)=2%、硅丙乳液聚合物的Tg(玻璃化转变温度)为-35℃和固液比为0.8时,制成的硅丙乳液/水泥基复合防水粘接涂层能够满足GB/T 23445—2009(Ⅰ型)标准中的指标要求。 相似文献
13.
14.
中空聚合物微球的制备——种子及核乳胶粒的制备 总被引:3,自引:0,他引:3
为了制得具有中空结构的聚合物微球,首先以十二烷基苯磺酸钠(SDBS)为乳化剂,在其用量低于CMC的条件下,进行甲基丙烯酸甲酯(MMA)、甲基丙烯酸(MAA)和丙烯酸丁酯(BA)的乳液聚合,制备了带羧基的种子乳胶粒.然后采用MMA、MAA和二乙烯基苯为单体进行种子乳液聚合,制备了轻度交联的带羧基的核乳胶粒.该核乳胶粒经过核-壳乳液聚合和适当的碱处理工艺就可成为具有中空结构的聚合物微球.采用粒度仪测定了乳胶粒的直径及其分布,采用TEM对乳胶粒结构形态进行了表征.研究了种子及核乳胶粒制备过程中单体加料方式、乳化剂用量及羧基单体种类等因素对聚合稳定性、乳胶粒直径及其分布以及最终的中空聚合物微球结构形态的影响,确定了制备种子及核乳胶粒的最佳工艺条件.在制备种子阶段,SDBS用量为单体总量的0.5%,采用一次性加入单体的进料工艺;在核乳胶粒制备阶段,以MAA为羧基单体,所有单体采用"饥饿式"加料,半连续补加乳化剂并使乳化剂用量为核单体总量的0.15%时可保持聚合稳定性并保证无新乳胶粒生成. 相似文献
15.
Ling L. Ching Wong Suelen Barg Angelika Menner Paula do Vale Pereira Goki Eda Manish Chowalla Eduardo Saiz Alexander Bismarck 《Polymer》2014
Reduced graphene oxide (rGO) is known to be electrically conductive and adsorb at oil–water interfaces. It has also been shown to mechanically reinforce bulk materials. This work combines these favourable characteristics of two-dimensional rGO to develop 3D macroporous polymer nanocomposites via emulsion templating. rGO proved to be an efficient emulsifier as only 0.2 mg/ml (with respect to the oil phase) of rGO was required to stabilise water-in-oil high internal phase emulsions (HIPE) of up to 80 vol.% internal phase. After polymerisation of the continuous minority monomer (styrene and divinylbenzene) phase, macroporous polymer nanocomposites with tuneable microstructures were obtained. The storage modulus of rGO-poly(styrene-co-divinylbenzene) HIPEs increased by almost an order of magnitude when the rGO concentration used to stabilise the HIPE template increased from 0.4 to 5.0 mg/ml. The adsorption and organisation of rGO at the o/w interface in HIPEs prior to polymerisation and partial aggregation in the polymer cell walls after polymerisation resulted in conductive nanocomposites with a rGO content of as low as 0.006 vol.% (with respect to bulk polymer volume or 0.8 mg/ml with respect to the monomer volume used in the emulsion template) compared to 0.1 vol.% for dense nanocomposites previously reported. This provided evidence for the efficient arrangement of rGO within the macroporous polymer nanocomposite, creating an electrically conductive network. 相似文献
16.
为确定某种特定的冷轧油乳化液配制时的工艺条件,研究了复配乳化剂种类、用量、乳化温度、乳化时间等参数对该乳液稳定性的影响规律。研究表明:将醚类与酯类的非离子乳化剂进行乳化,温度50℃,复配乳化剂用量占总乳化液的0.56%,油水体积比1∶19,搅拌时间50min下制得的冷轧油乳化液的稳定性符合我国现行乳化液稳定性行业标准。 相似文献
17.
在氧化-还原引发体系下进行原位乳液插层共聚合,制备了聚(甲基丙烯酸甲酯-丙烯酸甲酯)/有机蒙脱土[P(MMA-MA)/OMMT]纳米复合材料.通过分析制得乳液的稳定性及乳胶粒粒径,确定了最佳聚合工艺,包括最佳乳化剂浓度、引发剂浓度、反应温度等.结果表明:当乳化剂浓度为7%、引发剂浓度为0.3%和反应温度在60℃时,乳液中乳胶粒的粒径尺寸较小,且乳液稳定性很好. 相似文献
18.
Synthesis of polystyrene-clay nanocomposites via emulsion polymerization using a reactive surfactant
Summary
Polystyrene-clay nanocomposites were synthesized via emulsion polymerization of styrene in the presence of montmorillonite
particles and a reactive cationic surfactant as the emulsifier. The reactive surfactant, vinylbenzyldodecyldimethylammonium
chloride (VDAC), was synthesized by the quaternization reaction of vinylbenzyl chloride with dimethyldodecylamine. Partially
exfoliated nanocomposites were achieved as revealed by X-ray diffraction (XRD) and transmission electron microscopy (TEM).
Polystyrene-clay nanocomposites prepared by emulsion polymerization have higher glass transition temperature and dynamic modulus
than pure polystyrene.
Received: 27 February 2001 /Revised version: 14 February 2002 /Accepted: 14 February 2002 相似文献