PSt／PBA胶乳型互穿聚合物网络性质的研究

用乳液聚合技术制备了ＰＳｔ／ＰＢＡ胶乳型互穿聚合物网络，着重讨论了乳化剂、引发剂、交联剂及加料方式对其性能的影响。     

两亲性钠离聚体的合成、表征及其性质

以偶氮二异丁腈为引发剂,聚氧乙烯(PEO)大单体在苯中与丙烯酸丁酯和丙烯酸共聚,合成了含聚氧乙烯支链的丙烯酸丁酯-丙烯酸接枝共聚物。以此共聚物为前体,经NaOH的甲醇溶液中和,合成了同时含有非离子、阴离子的两亲性钠离聚体。红外光谱、膜渗透压计、凝胶渗透色谱、透射电子显微镜等表征结果显示,前体和两亲性钠离聚体为规整接枝共聚物,平均接枝数为6.5～16.1;前体中聚氧乙烯支链与主链中的丙烯酸链节生成氢键,而两亲性钠离聚体中此氢键消失。两亲性钠离聚体有良好的乳化性、吸水性和相转移催化性质。当聚氧乙烯的质量分数由30.2%增至45.0%时,两亲性钠离聚体的吸水率由105%增至175%;随两亲性钠离聚体加入量的增加,Williamson固液反应中的固体苯酚钾转化率提高。固体苯酚钾转化率最大可达83.3%。     

The effect of temperature and vibration on emulsion stability of mayonnaise in two different package types

Mayonnaise in two different packages was compared for its susceptibility to vibration-induced breakdown. The researchers investigated the effect of truck vibration on emulsion stability and compared two different package systems. The containers were 32 oz glass and 32 oz polyethylene terephthalate (PET). Mayonnaise was conditioned at three different temperatures (40°, 72° and 100 °F), for three time periods (21, 26 and 36 days), and vibrated at normal and worst-case transportation g levels. Emulsion stability was quantified by specific gravity, percentage of surface oil, and qualitatively rated by a visual pass/fail test. The specific gravity measure positively correlated to surface oiling. Glass containers showed a higher rate of emulsion failure at the worst-case vibration levels. No consistent difference in emulsion breakdown was found between plastic and glass at the normal transportation g levels.     

可碱溶丙烯酸酯共聚压敏胶乳液的研制

介绍了一种壳核结构丙烯酸酯共聚乳液的制备工艺、性能,该乳液适用于生产可碱溶回收压敏胶带纸及商标纸等。     

A novel technique for preparing organophilic silica by water-in-oil microemulsions

Summary A novel technique to prepare ultramicro spherical silica particles containing vinyl groups on their surfaces is presented. This process is a combination of the sol-gel technique and the water-in-oil microemulsion technique in which hydrolysis and condensation of TEOS [Si(OEt)₄] and MPS (trimethoxysilylpropylmethacrylate) take place. Spherical silica particles with a size range from 20 to 70 nm were obtained and the surface concentrations of the double bonds per nm² were from 4 to 7.     

Water‐soluble/dispersible cationic pressure‐sensitive adhesives. II. Adhesives from emulsion polymerization

In our previous work, we reported that cationic water‐soluble pressure‐sensitive adhesives (PSAs) could be synthesized in ethanol or methanol. These cationic water‐soluble adhesives would not cause a stickies problem during paper recycling and can be easily removed from the papermaking system by adsorbing on wood fibers. In this study we report the synthesis and application of water‐based cationic PSAs using miniemulsion polymerization. A redox initiator system of cumene hydroperoxide/tetraethylenepentamine was used to force interfacial polymerization. The end‐use properties of the PSAs were evaluated, and the repulpability of the PSAs in paper recycling was studied. It was found that the cationic PSA from miniemulsion polymerization itself was insoluble and nondispersible in water during the paper recycling process. However, if this water‐insoluble cationic PSA from miniemulsion was formulated with a water‐soluble cationic PSA made from ethanol, the solubility or dispensability of the former PSA in water was improved. The molecular weight and degree of crosslinking of the PSA polymer have significant effects on the properties and dispersability of PSA. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 347–353, 2004     

聚丙烯酸-腐植酸钠复合高吸水树脂的合成研究

该研究采用不除去丙烯酸中阻聚剂及不通氮气的工艺,以丙烯酸、腐植酸钠为原料,通过水溶液聚合法制备了聚丙烯酸-腐植酸钠复合高吸水树脂。研究结果表明:该复合高吸水树脂在丙烯酸的中和度为60%,腐植酸钠用量为1.0g,引发剂过硫酸钾用量为55mg,交联剂N,N'-亚甲基双丙烯酰胺用量为20mg时,吸蒸馏水量最大,为1200g/g。     

模拟海洋大气环境下铝合金表面锌黄环氧底漆/丙烯酸聚氨酯面漆涂层体系失效过程研究

目的研究5A06型铝基材所使用的锌黄环氧底漆/丙烯酸聚氨酯面漆涂层体系的失效过程。方法设计"紫外/冷凝3 d+中性盐雾3 d+低温暴露1 d"为一个周期的实验室循环加速试验,采用交流阻抗谱法,结合光泽度、色差值、红外光谱等数据,研究涂层体系性能。结果循环加速试验进行到16周,该过程中面漆的失光率、色差值上升,达到轻微失光等级和轻微变色等级。面漆的表面形貌及涂层的低频阻抗发生明显变化,第12周时在光学显微镜下明显可见微小鼓泡,涂层0.1 Hz阻抗保持在109W·cm~2以上,但此后鼓泡数量增加,部分鼓泡破损,颜填料流出;第14周时,0.1 Hz阻抗下降到108W·cm~2,此后鼓泡数量进一步增加,部分鼓泡处面漆脱落;第16周时,0.1 Hz阻抗下降到约为107W·cm~2。结论丙烯酸聚氨酯面漆树脂基体特征官能团、聚合物链发生断裂,面漆的完整性遭到破坏,这可能与紫外线照射相关。这将加速涂层中腐蚀性介质(如水、氧和侵蚀性氯离子)渗透,促进涂层的失效。     

Significance of polymer on emulsion stability in surfactant‐polymer flooding

The influence of polymer on stability and shear rate on droplet size of emulsion is evaluated in the laboratory, microstructure of the emulsion is observed under a microscope, and the pore distribution of the cores is analyzed through mercury injection experiments. In the process of surfactant‐polymer (SP) flooding, the thickness of polymer absorbed on the surface of the rock is calculated by a mathematical model. The experiments show that the polymer is good for the stability of emulsion, with the increase of shear rate, stability becomes better, and droplet size gets smaller. Due to the adsorption of polymer, the pore throat turns narrow, seepage velocity is increasing, and also the emulsion becomes more stable with the smaller‐size droplets. During the single emulsifier flooding, the emulsion is easy to coalescence for its instability, and the seepage channel can be easily blocked, which leads to the high injection pressure. Consequently, the polymer plays an important role on emulsion stability in SP flooding. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42171.     

High‐mechanical‐strength ferrohydrogels with a magnetically dispersed phase as multifunctional crosslinkers

In this article, we report a facile strategy for preparing high‐mechanical‐strength ferrohydrogels containing magnetic nanoparticles homodispersed by a thermodynamically stable Pickering emulsion (PE). After the monomers were mixed with the PE, including methacryloxy propyl trimethoxyl silane emulsified by ferric oxide (Fe₂O₃) nanoparticles as the dispersed phase, hydrogels were synthesized by free‐radical polymerization. In contrast to conventional hydrogels crosslinked by a molecular crosslinker, in our new approach, the magnetic PE particles served as individual, multifunctional crosslinkers. Characterizations of the swelling behavior, the mechanical properties, and other properties indicated that our ferrohydrogels exhibited outstanding physical performances that were superior to those of traditional hydrogels and magnetic responsiveness. These ferrohydrogels may have applications in soft and controllable actuators. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41950.