To avoid the damage to catalytic system in ATRP by the carboxyl groups in vinyl benzoic acid, a well defined poly( p vinyl benzoic acid) was synthesized via ATRP in the tertiary butyl ester form. The ATRP of t butyl p...To avoid the damage to catalytic system in ATRP by the carboxyl groups in vinyl benzoic acid, a well defined poly( p vinyl benzoic acid) was synthesized via ATRP in the tertiary butyl ester form. The ATRP of t butyl p vinyl benzoate ( t BVB) was studied kinetically. The results showed that t BVB can be polymerized in a controlled way by ATRP. It was found that the polymerization rate of t BVB is much faster than that of St, meaning that the electron withdrawing ester group affects the polymerization obviously. Well defined diblock copolymers of St and t BVB were prepared by using bromo terminated PBVBs as macroinitiators via ATRP. After removal of the t butyl group by hydrolysis, well defined amphiphilic diblock copolymers of styrene and p vinyl benzoic acid (PSt b PBVA) were obtained.展开更多
目的建立复方鲜竹沥液中对羟基苯甲酸乙酯的含量测定方法。方法以Lichrospher C18柱(4.6×250mm,5μm)为色谱柱;以A:0.025mol·L-1磷酸二氢钠溶液(磷酸调p H 3.7)-B:甲醇为梯度洗脱;检测波长:258nm;流速:1.0m L·mi...目的建立复方鲜竹沥液中对羟基苯甲酸乙酯的含量测定方法。方法以Lichrospher C18柱(4.6×250mm,5μm)为色谱柱;以A:0.025mol·L-1磷酸二氢钠溶液(磷酸调p H 3.7)-B:甲醇为梯度洗脱;检测波长:258nm;流速:1.0m L·min-1;柱温:35℃。结果对羟基苯甲酸乙酯在0.6915~55.32μg·m L-1范围内呈良好的线性关系(r=0.9999),平均回收率为96.31%,RSD为1.17%(n=6)。结论本方法简便可行,重现性好,可用于复方鲜竹沥液中对羟基苯甲酸乙酯的含量测定。展开更多
文摘To avoid the damage to catalytic system in ATRP by the carboxyl groups in vinyl benzoic acid, a well defined poly( p vinyl benzoic acid) was synthesized via ATRP in the tertiary butyl ester form. The ATRP of t butyl p vinyl benzoate ( t BVB) was studied kinetically. The results showed that t BVB can be polymerized in a controlled way by ATRP. It was found that the polymerization rate of t BVB is much faster than that of St, meaning that the electron withdrawing ester group affects the polymerization obviously. Well defined diblock copolymers of St and t BVB were prepared by using bromo terminated PBVBs as macroinitiators via ATRP. After removal of the t butyl group by hydrolysis, well defined amphiphilic diblock copolymers of styrene and p vinyl benzoic acid (PSt b PBVA) were obtained.