Environmentally benign formation of polymeric microspheres by rapid expansion of supercritical carbon dioxide solution with a nonsolvent.
Environmentally benign formation of polymeric microspheres by rapid expansion of supercritical carbon dioxide solution with a nonsolvent.
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通过超临界二氧化碳溶液与非溶剂的快速膨胀形成环境友好的聚合物微球。
DOI：
10.1021/es0105966
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发表时间：
2001
影响因子：
11.4
通讯作者：
S. Yamaguchi
中科院分区：
文献类型：
--
作者：
K. Matsuyama;K. Mishima;H. Umemoto;S. Yamaguchi
报道了一种用于形成聚合物微粒的新方法，其减少了在涂料工业中用作涂料溶剂的对环境有害的挥发性有机化合物如甲苯和二甲苯的大气排放。聚合物微粒是通过超临界溶液与非溶剂（RESS-N）的快速膨胀形成的。聚（苯乙烯）-B-（聚（甲基丙烯酸甲酯）-共-聚（甲基丙烯酸缩水甘油酯））共聚物（PS-B-（PMMA-共-PGMA），MW = 5000，PS/PMMA/PGMA = 2/5/3）、聚（乙二醇）（PEG，M. W = 4000）、双酚A型环氧树脂（EP，MW = 3000）、聚（甲基丙烯酸甲酯）（PMMA; MW = 15000、75000、120000）和聚（氧化烯）烷基苯基醚（MW = 4000）在二氧化碳（CO2）中的混合物。PS-b-（PMMA-co-PGMA）在CO2或乙醇中的溶解度极低，但在两者的混合物中变为20重量%。因为乙醇是聚合物的非溶剂，所以它可以用作从超临界溶液快速膨胀的共溶剂，以产生不附聚的1-3微米颗粒。将通过RESS-N获得的聚合物颗粒作为粉末涂料施用。所得涂层具有光滑且连贯的膜。通过改变聚合物浓度、预膨胀压力、温度和注射距离来控制微球的粒径分布。在控制颗粒大小方面，进料组成比其他因素更有效。用RESS-N方法形成的聚合物微粒可用于制备薄涂膜，而不需要任何有毒的有机溶剂和/或表面活性剂。
A novel method is reported for forming polymer microparticles, which reduce atmospheric emissions of environmentally harmful volatile organic compounds such as toluene and xylene used as paint solvent in paint industry. The polymer microparticles have formed through rapid expansion from supercritical solution with a nonsolvent (RESS-N). Solubilization of poly(styrene)-b-(poly(methyl methacrylate)-co-poly (glycidyl methacrylate)) copolymer(PS-b-(PMMA-co-PGMA), MW = 5000, PS/PMMA/PGMA = 2/5/3), poly(ethylene glycol) (PEG, M. W = 4000), bisphenol A type epoxy resin (EP, MW = 3000), poly(methyl methacrylate) (PMMA; MW = 15000, 75000, 120000), and poly(oxyalkylene) alkylphenyl ether (MW = 4000) in carbon dioxide (CO2) was achieved with the use of small alcohols as cosolvents. The solubility of the PS-b-(PMMA-co-PGMA) is extremely low in either CO2 or ethanol but becomes 20 wt % in a mixture of the two. Because ethanol is a nonsolvent for the polymer, it can be used as a cosolvent in rapid expansion from supercritical solution to produce 1-3 microm particles that do not agglomerate. Obtained polymer particles by RESS-N were applied as powder coatings. The resulting coatings have a smooth and coherent film. The particle size distribution of microspheres was controlled by changing the polymer concentration, preexpansion pressure, temperature, and injection distance. The feed compositions were more effective than the other factors in controlling the particle size. The polymeric microparticles formed by RESS-N method can be utilized to make the thin coating film without anytoxic organic solvents and/or surfactants.