反应型乳化剂在核壳丙烯酸酯乳液合成中的应用

本研究采用种子乳液聚合法,将反应型乳化剂、非离子型乳化剂和阴离子型乳化剂进行复配,以BA、St、MMA、AA为单体合成了具有核壳结构的聚丙烯酸酯类乳液。试验表明：乳化剂用量为2.5%,G-30∶NP40∶HAPS比例为1∶2∶1,乳化剂在核壳中的比例为2∶1,得到的乳液具有核壳结构,胶膜综合性能良好。     

Properties of polyacrylate latex prepared under different emulsified systems

The polyacrylate latexes were synthesized via pre-emulsified and semi-continuous seeded emulsion polymerization technology when conventional surfactant or polymerizable surfactant was used as emulsifiers. The resultant latexes and their films were characterized with the contact angle determinator and rheometer. Effect of the polymerizable surfactant on water resistance, stability and rheology of the latex was studied. Results show that the water resistance of film is increased first then decreased with the increase of the amount of the polymerizable surfactant. There exists the optimum value of the amount of the polymerizable surfactant for the water resistance of the film. In comparison with the latex prepared with the conventional surfactant, both the mechanical stability and the freezing-thaw stability of the latex are improved when the polymerizable surfactant is used during the course of the emulsion polymerization. The resultant latex has rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.     

聚丙烯酸羟乙酯醋酸乙烯酯乳液表面施胶剂的合成与应用

通过在传统的聚丙烯酸酯乳液聚合中添加功能性单体制备丙烯酸酯共聚物表面施胶剂。分析了影响乳液性能的几种主要因素,如单体的配比、功能单体的加入量、引发剂、乳化剂等,确定了表面施胶剂较佳的合成工艺条件。应用实验结果表明,该施胶剂不论是单独使用还是与氧化淀粉配合使用都有很好的表面施胶效果,纸张施胶度可以达到25s以上,拉毛速度高于280cm·s~(-1)。     

自交联封闭性乳液的合成与性能

以双丙酮丙烯酰胺（DAAM）、甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）和甲基丙烯酸（MAA）为共聚单体，采用半连续种子乳液聚合工艺合成自交联封闭性聚丙烯酸酯乳液（PAE），考察了DAAM和复合乳化剂对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着DAAM含量的增加，乳液聚合稳定性下降，粒径增大，涂膜的耐介质性能和交联度提高，合适的DAAM加入量为总单体质量的3.0%，DAAM和己二酰肼(ADH)的最佳摩尔比为2∶1。采用SDBS+OP-10+OP-40为复合乳化剂体系，选用乳化剂的含量为2.35%，阴/非离子乳化剂质量比为1∶1.25；复合乳化剂在种子、核、壳比例为1.5∶1∶2，制备的乳液具有较好的聚合稳定性（乳液凝胶率低和单体转化率高），乳液耐电解质（钙离子）稳定性好，涂膜具有优异的封闭性。傅里叶红外光谱（FTIR）表明在涂膜形成过程中DAAM的酮羰基与ADH的酰肼基反应生成腙（C=N），TEM分析显示乳液的乳胶粒子呈核壳结构，TGA分析发现DAAM改性的PAE降低了涂膜的热稳定性。     

Effects of carboxyl group on the ambient self‐crosslinkable polyacrylate latices

Ambient curable carbonyl functional acrylic latices were synthesized by incorporating diacetone acrylamide as functional monomer into acrylic copolymer, adipic acid dihydrazide (ADH) was used as curing agent. In this work acrylic acid (AA) and acrylic acid homopolymer (PAA) were used to facilitate the crosslinking reaction. We found that the properties of latex film were different when use AA and PAA as the source of the carboxyl groups separately. The results from the characterization of carboxyl groups of the latex particles demonstrated that the distribution of the carboxyl group on the latex particle surface is optimal for the crosslinking reaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3948–3953, 2007     

双端丙烯酰氧基聚醚硅油的制备及其改性聚丙烯酸酯性能

 采用丙烯酸和双端羟基聚醚硅油为原料，通过酯化反应制备了双端丙烯酰氧基聚醚硅油，研究了催化剂用量、反应温度和时间、溶剂和阻聚剂用量等因素对酯化率影响，用FTIR和1H-NMR对产物结构进行了表征；并将其应用于聚丙烯酸酯乳液制备，测定了改性乳液及其涂料印花性能。结果表明：酯化反应最佳条件为：催化剂和溶剂用量分别为反应物总质量的5%、70%，阻聚剂用量为丙烯酸质量的0.75%，反应温度为110℃，反应时间为4h；FTIR和1H-NMR谱图表明酯化产物结构为丙烯酰氧基聚醚改性硅油；改性乳液胶膜的疏水性变大，断裂强度略有下降，断裂延伸率明显变大，断裂功略有增加；改性乳液应用于涂料印花，印花织物干、湿摩可达4级及以上，手感柔软。