The ring-opening polymerization of 1,4-dioxan-2-one （PDO） was carried out by lanthanum tris（2,6-di-tert-butyl-4- methylphenolate） （La（OAr）3） as novel single component initiaLor. The influences of polymerizatio...The ring-opening polymerization of 1,4-dioxan-2-one （PDO） was carried out by lanthanum tris（2,6-di-tert-butyl-4- methylphenolate） （La（OAr）3） as novel single component initiaLor. The influences of polymerization reaction temperature and the molar ratio of monomer to initiator on the monomer conversion and molecular weight of poly（1,4-dioxan-2-one） （PPDO） were explored. PPDO with high viscosity average molecular weight of 1.95×10^5 can be prepared at 40℃ when [PDO]/ [La（OAr）3] molar ratio was 800. Mechanism investigation shows that the polymerization proceeds through a ＂coordination- insertion＂ mechanism with selective rupture of acyl-oxygen be,nd of PDO.展开更多
The polymerization of n-hexyl isocyanate(HNCO) was carried out in the presence of a novel single initiator, rare earth tris(2,6-di-tert-butyl-4-methylphenolate)[Ln(OAr)_3]. The influences of reaction conditions such a...The polymerization of n-hexyl isocyanate(HNCO) was carried out in the presence of a novel single initiator, rare earth tris(2,6-di-tert-butyl-4-methylphenolate)[Ln(OAr)_3]. The influences of reaction conditions such as the monomer concentration, the polymerization temperature and time, and the types of solvents on the polymerization of HNCO were studied. Polymerizations of phenyl, i-propyl, p-tolyl, n-butyl and n-octyl isocyanates with La(OAr)_3 were also examined.展开更多
建立了超高效液相色谱法测定注射用埃索美拉唑钠中的2,6-二叔丁基-4-甲基苯酚(BHT)和4-叔丁基酚。采用二氯甲烷提取4-叔丁基酚和BHT,使用Eclipse plus C18柱,流动相为水和甲醇,线性梯度洗脱,检测波长280 nm。结果表明,BHT和4-叔丁基酚在...建立了超高效液相色谱法测定注射用埃索美拉唑钠中的2,6-二叔丁基-4-甲基苯酚(BHT)和4-叔丁基酚。采用二氯甲烷提取4-叔丁基酚和BHT,使用Eclipse plus C18柱,流动相为水和甲醇,线性梯度洗脱,检测波长280 nm。结果表明,BHT和4-叔丁基酚在0.4~10.0μg/ml范围内线性关系良好,回收率为81%~117%,RSD为0.4%~6.6%。本方法简捷、可靠,可为不同制剂中BHT和4-叔丁基酚的迁移量测定提供参考。展开更多
基金This work was financially supported by the financial support of National Natural Science Foundation of China (No. 20434020)
文摘The ring-opening polymerization of 1,4-dioxan-2-one （PDO） was carried out by lanthanum tris（2,6-di-tert-butyl-4- methylphenolate） （La（OAr）3） as novel single component initiaLor. The influences of polymerization reaction temperature and the molar ratio of monomer to initiator on the monomer conversion and molecular weight of poly（1,4-dioxan-2-one） （PPDO） were explored. PPDO with high viscosity average molecular weight of 1.95×10^5 can be prepared at 40℃ when [PDO]/ [La（OAr）3] molar ratio was 800. Mechanism investigation shows that the polymerization proceeds through a ＂coordination- insertion＂ mechanism with selective rupture of acyl-oxygen be,nd of PDO.
文摘The polymerization of n-hexyl isocyanate(HNCO) was carried out in the presence of a novel single initiator, rare earth tris(2,6-di-tert-butyl-4-methylphenolate)[Ln(OAr)_3]. The influences of reaction conditions such as the monomer concentration, the polymerization temperature and time, and the types of solvents on the polymerization of HNCO were studied. Polymerizations of phenyl, i-propyl, p-tolyl, n-butyl and n-octyl isocyanates with La(OAr)_3 were also examined.
文摘建立了超高效液相色谱法测定注射用埃索美拉唑钠中的2,6-二叔丁基-4-甲基苯酚(BHT)和4-叔丁基酚。采用二氯甲烷提取4-叔丁基酚和BHT,使用Eclipse plus C18柱,流动相为水和甲醇,线性梯度洗脱,检测波长280 nm。结果表明,BHT和4-叔丁基酚在0.4~10.0μg/ml范围内线性关系良好,回收率为81%~117%,RSD为0.4%~6.6%。本方法简捷、可靠,可为不同制剂中BHT和4-叔丁基酚的迁移量测定提供参考。
