RING-OPENING POLYMERIZATION OF l,4-DIOXAN-2-ONE INITIATED BY LANTHANUM TRIS(2,6-DI-TERT-BUTYL-4-METHYLPHENOLATE)

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.

Polymerization of n-Hexyl Isocyanate Initiated by Novel Rare Earth Tris(2,6-di-tert-butyl-4-methylphenolate)

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.

Polymerization of Phenyl Isocyanate by Divalent Samarium Complex (ArO)_2Sm(THF)_4 (ArO=2,6-di-tert-butyl-4-methylphenoxo)

Phenyl isocyanate was for the first time successfully polymerized by divalent samarium complex (ArO)2Sm(THF)4. The monomer concentration and temperatur affected the polymerization greatly.

2,6-二叔丁基对硝基苯酚的合成与表征

以2，6-二叔丁基苯酚为原料，石油醚为溶剂，通过硝化反应合成了抗氧剂中间体2，6-二叔丁基对硝基苯酚，并采用元素分析和红外光谱对其结构进行表征。通过条件实验得出2，6-二叔丁基对硝基苯酚的最佳合成条件为：硝酸浓度为30％，反应原料摩尔比为1：1．5，反应时间为10h，此条件下，2，6-二叔丁基对硝基苯酚的产率为81．6％，熔点为156．9—157．8℃。

Rare Earth Complex Initiated Ring-Opening Polymerization of 2,2-Dimethyltrimethylene Carbonate

The ring opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) initiated by single component of tris(2,6-di-tert-butyl-4-methylphenoxo) lanthanide (Ln(OAr)(3)) is reported. The initiators are highly active to the polymerization and give high molecular weight polymers. (HNMR)-H-1 spectra and DSC measurement suggest the polymerization is free of decarboxylation. Mechanism study shows that the monomer insertion is via the break of acyl-oxygen bond of DTC.

一种2,6-二叔丁基-4-硝基苯酚的测试方法及纺织品潜在酚黄变的评估方法研究

检测机构在纺织产品潜在酚黄变评估中,发现缺少引起酚黄变的质控物质DTNP的验收,也没有测试DTNP的测试方法。本文用液相色谱-质谱仪对酚黄变标准样卡中2,6-二叔丁基-4-硝基苯酚进行测试。目标分析物DTNP在0.05μg/mL~0.4μg/mL浓度范围内与峰面积响应和质量浓度呈线性关系,r=0.9995,最低检出浓度0.025μg/mL。在0.05μg/mL浓度下平均相对标准偏差为2.90%。此方法可以对酚黄变标准样品进行质控、验收,也可以给纺织产品酚黄变评级提供数据参考。