Covolan Vera Lúcia, Galembeck Fernando, Leite Carlos Alberto de Paula, Ruggeri Giacomo, Chiellini Emo
Instituto de Química, Universidade Estadual de Campinas-UNICAMP, P.O. Box 6154, CEP 13083-970, Campinas, São Paulo, Brazil.
J Colloid Interface Sci. 2004 May 1;273(1):121-30. doi: 10.1016/j.jcis.2004.01.070.
Different samples of aminated latex of poly(styrene-co-Boc-aminostyrene) microspheres with mean diameters varying from 0.7 to 1.0 microm were prepared by dispersion copolymerization of styrene (ST) and Boc-aminostyrene (Boc-AMST). The copolymer compositions determined by nuclear magnetic resonance (1H NMR) were Boc-AMST/ST 6.9/93.1 mol/mol % (BOC7 sample) and Boc-AMST/ST 31.3/68.7 mol/mol % (BOC30 sample). The average molecular weights determined by gel permeation chromatography were 126 kDa (BOC7 sample) and 51 kDa (BOC30 sample). The latex containing NH-carbo-tert-butoxy groups (NH-Boc) were treated with 2 M HCl in isopropyl alcohol/water (1:1 vol/vol), at 50 degrees C for 3, 6, 9, 24, and 30 h, in order to control the extent of deprotection reaction of the NH-Boc. The deprotection reaction resulted in the formation of NH3+Cl- groups on the particle surfaces. The kinetic of the deprotection reaction was investigated by 1H NMR analyses and the yield varied from 20 to 40%. The resulting -NH3+Cl- groups on the microsphere surfaces were examined, in particular, by electron spectroscopy imaging (ESI) using an energy-filtered transmission electron microscope (EFTEM) that clearly demonstrated the presence of Cl on the particle surfaces. Scanning electron photomicrographs recorded for the above samples showed that the particle morphology was maintained after the acidic treatment.
通过苯乙烯（ST）和叔丁氧羰基氨基苯乙烯（Boc-AMST）的分散共聚反应，制备了平均直径在0.7至1.0微米之间的不同样品的聚（苯乙烯-共-Boc-氨基苯乙烯）微球胺化胶乳。通过核磁共振（1H NMR）测定的共聚物组成分别为Boc-AMST/ST 6.9/93.1摩尔/摩尔%（BOC7样品）和Boc-AMST/ST 31.3/68.7摩尔/摩尔%（BOC30样品）。通过凝胶渗透色谱法测定的平均分子量分别为126 kDa（BOC7样品）和51 kDa（BOC30样品）。含有NH-叔丁氧羰基（NH-Boc）基团的胶乳在50℃下用异丙醇/水（1:1体积/体积）中的2 M HCl处理3、6、9、24和30小时，以控制NH-Boc的脱保护反应程度。脱保护反应导致颗粒表面形成NH3+Cl-基团。通过1H NMR分析研究了脱保护反应的动力学，产率在20%至40%之间变化。特别是使用能量过滤透射电子显微镜（EFTEM）通过电子能谱成像（ESI）对微球表面产生的-NH3+Cl-基团进行了检查，结果清楚地表明颗粒表面存在Cl。对上述样品记录的扫描电子显微镜照片显示，酸性处理后颗粒形态得以保持。
