• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Polymers and the Environment >Stability of Aqueous Suspensions of Medium-Chain-Length Poly-3-Hydroxyalkanoate Particles
【24h】

Stability of Aqueous Suspensions of Medium-Chain-Length Poly-3-Hydroxyalkanoate Particles

机译：中链长的聚3-羟基链烷酸酯颗粒的水悬浮液的稳定性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Although poly-3-hydroxyalkanoates (PHAs) and particularily medium-chain-length (mcl)-PHAs are likely to find industrial applications in a latex form, very few studies have examined their behavior in aqueous suspension and none have examined the dense suspensions required commercially. For this reason, the stability of mcl-PHA latexes containing saturated aliphatic (65 mol% 3-hydroxynonanoate, PHN), and for the first time, with vinyl (PHNU) or carboxylated side chains was examined. At 4 g L-1 with no stabilizing agent, PHNU nanoparticles (199.4 +/- A 3.6 nm) were significantly smaller than those of PHN (211.5 +/- A 6.4 nm) while carboxylated PHN nanoparticles (76.1 +/- A 6.4 nm) were substantially smaller than those of either PHN or PHNU with particles stable for more than 110 days. Increasing the PHN concentration to 10 g L-1 also resulted in stable latexes but with larger particles (410.8 +/- A 5.2 nm). Adjusting the pH of the suspending medium (water) before addition of the polymer (dissolved in acetone) resulted in much smaller PHN particles at pH = 11.3 (134 +/- A 2 nm) than at pH = 4.3 (312 +/- A 8 nm) at a 4 g L-1 final polymer concentration. Zeta potentials of PHN suspensions decreased with pH, likely due to the carboxyl end groups. Above a pH of 4.0, adjusting the pH after particle formation had little effect. NaCl addition could be used to agglomerate and ultimately precipitate the particles. Stabilizers such as surfactants will likely be required to produce denser mcl-PHA latexes with suitable particle size for certain applications such as coatings and toner production.
机译：尽管聚-3-羟基链烷酸酯（PHA）特别是中链长度（mcl）-PHA可能以乳胶形式在工业上找到应用，但很少有研究检查它们在水悬浮液中的行为，也没有研究检查所需的稠密悬浮液商业上。因此，研究了含饱和脂族（65摩尔％3-羟基壬酸酯，PHN）的mcl-PHA胶乳的稳定性，并首次检测了其具有乙烯基（PHNU）或羧化侧链的稳定性。在没有稳定剂的4 g L-1下，PHNU纳米颗粒（199.4 +/- A 3.6 nm）显着小于PHN（211.5 +/- A 6.4 nm），而羧化PHN纳米颗粒（76.1 +/- A 6.4 nm） ）的粒子数要比PHN或PHNU的粒子数小得多，并且粒子的稳定时间超过110天。将PHN浓度增加到10 g L-1也会产生稳定的乳胶，但颗粒较大（410.8 +/- A 5.2 nm）。在添加聚合物（溶解在丙酮中）之前调节悬浮介质（水）的pH值，导致pH = 11.3（134 +/- A 2 nm）的PHN颗粒比pH = 4.3（312 +/- A）小得多L-1最终聚合物浓度为8 nm）。 PHN悬浮液的Zeta电位随pH降低，这可能是由于羧基端基所致。 pH值大于4.0时，在颗粒形成后调节pH值影响很小。添加氯化钠可用于团聚并最终使颗粒沉淀。对于某些应用（例如涂料和调色剂生产），可能需要稳定剂（例如表面活性剂）来生产具有合适粒度的致密mcl-PHA胶乳。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号