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首页> 外文期刊>Journal of Applied Polymer Science >SYNTHESIS OF UNIFORM MICROSPHERES WITH HIGHER CONTENT OF 2-HYDROXYETHYL METHACRYLATE BY EMPLOYING SPG (SHIRASU POROUS GLASS) EMULSIFICATION TECHNIQUE FOLLOWED BY SWELLING PROCESS OF DROPLETS
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SYNTHESIS OF UNIFORM MICROSPHERES WITH HIGHER CONTENT OF 2-HYDROXYETHYL METHACRYLATE BY EMPLOYING SPG (SHIRASU POROUS GLASS) EMULSIFICATION TECHNIQUE FOLLOWED BY SWELLING PROCESS OF DROPLETS

机译：运用溶胀过程的SPG（Shirasu多孔玻璃）乳化技术合成更高含量的甲基丙烯酸2-羟乙酯的均匀微球。

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Relatively uniform microspheres containing a hydrophilic monomer, 2-hydroxyethyl methacrylate (HEMA), were prepared by employing a swelling method of uniform seed droplets. A uniform seed emulsion composed mainly of styrene (St) was prepared by the Shirasu porous glass (SPG) membrane emulsification technique; this was mixed with a secondary emulsion composed mainly of HEMA/St or HEMA/MMA (methyl methacrylate) prepared by a homogenizer for swelling. The swollen droplets obtained were polymerized at 75 degrees C under a nitrogen atmosphere. The uniform microsphere with a higher content of HEMA was obtained successfully by the swelling method while it failed by a direct emulsification method. The effects of the composition of the oil phase and the inhibitor in the continuous phase on the incorporated fraction of HEMA, the morphology of particles, and monomer conversion were investigated. It was found that the incorporated fraction of HEMA increased with increasing its feed fraction, and more HEMA was incorporated into the microsphere when HEMA/MMA was used as the oil phase of the secondary emulsion rather than HEMA/St. Although the final conversion was very low when the feed fraction of HEMA was higher, it can be increased to more than 80% by using an adequate amount of ethylene glycol dimethacrylate (EGDMA) as a crosslinker and NaNO2 as an inhibitor in the aqueous phase. Various microspheres with different morphologies such as spherical, snowmanlike, and popcornlike were observed, depending on composition of the oil phase. Furthermore, the porous microsphere with a high content of HEMA was obtained by employing hexanol (HA) as a porogen. (C) 1997 John Wiley & Sons, Inc. [References: 29]
机译：通过使用均匀种子液滴的溶胀方法，制备了相对均匀的含有亲水性单体甲基丙烯酸2-羟乙酯（HEMA）的微球。通过Shirasu多孔玻璃（SPG）膜乳化技术制备了主要由苯乙烯（St）组成的均匀种子乳液。将其与主要由均质机制备的，主要由HEMA / St或HEMA / MMA（甲基丙烯酸甲酯）组成的二次乳液混合以进行溶胀。将得到的溶胀的液滴在氮气气氛下在75℃下聚合。通过溶胀法成功获得了HEMA含量较高的均匀微球，而通过直接乳化法则失败了。研究了连续相中油相和抑制剂的组成对HEMA掺入比例，颗粒形态和单体转化率的影响。发现HEMA的掺入分数随其进料分数的增加而增加，并且当使用HEMA / MMA而不是HEMA / St作为第二乳液的油相时，更多的HEMA被掺入微球。尽管当HEMA的进料分数较高时最终转化率非常低，但可以通过在水相中使用适量的乙二醇二甲基丙烯酸酯（EGDMA）作为交联剂和NaNO2作为抑制剂将其提高至80％以上。根据油相的组成，观察到各种具有不同形态的微球，例如球形，雪人状和爆米花状。此外，通过使用己醇（HA）作为致孔剂获得了具有高HEMA含量的多孔微球。 （C）1997 John Wiley＆Sons，Inc. [参考：29]

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