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
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
Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa i...Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃?- 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.展开更多
The mixed-ligand complexes of molybdenum(VI) with dithiolphenols (DP) {2,6-dithiol-4-methylphenol (DTMP), 2,6-dithiol-4-ethylphenol (DTEP) and 2,6-dithiol-4-tert-butylphenol (DTBP)} in the presence of hydrophobic amin...The mixed-ligand complexes of molybdenum(VI) with dithiolphenols (DP) {2,6-dithiol-4-methylphenol (DTMP), 2,6-dithiol-4-ethylphenol (DTEP) and 2,6-dithiol-4-tert-butylphenol (DTBP)} in the presence of hydrophobic amines have been investigated by spectrophotometric method. The condition of complexing and extraction, physical-chemical and analytical characteristics of this complex have been found. As hydrophobic amine 2(N, N-dimethylaminomethyl)-4-methylrphenol (АP1) and 2(N, N-dimethylaminomethyl)-4-xlor-phenol (AP2), 2 (N, N-dimethylamino-methyl)-4-brom-phenol (AP3) were used. It has been found that mixed-ligand complex was formed in weakly acidic medium (pH 4.1 - 5.9). The maximum analytical signal when complexing Mo(V) is observed at 516 - 534 nm. The calculated molar absorption (εmax) belongs to the range (4.16 - 5.35) × 104. The Beer’s law was applicable in the range of 0.3 - 22 μg/ml. The extraction photometric methods of the molybdenum determination were processed. The influence of diverse ions on determination of molybdenum has been studied. The proposed method was applied successfully to determine amount of molybdenum in steel and in soil.展开更多
目的:建立药用丁基橡胶塞中添加剂[抗氧剂264(2,6-二叔丁基-4-甲基苯酚,简称BHT)和硫化剂可提取硫]的含量测定方法。方法:以二氯甲烷-无水乙醇为提取溶剂,利用高效液相色谱法对药用丁基橡胶塞的BHT和可提取硫含量进行测定,以含0.1%三氟...目的:建立药用丁基橡胶塞中添加剂[抗氧剂264(2,6-二叔丁基-4-甲基苯酚,简称BHT)和硫化剂可提取硫]的含量测定方法。方法:以二氯甲烷-无水乙醇为提取溶剂,利用高效液相色谱法对药用丁基橡胶塞的BHT和可提取硫含量进行测定,以含0.1%三氟乙酸的乙腈-含0.1%三氟乙酸的水(90∶10)为流动相,流速1.0 m L·min^(-1),检测波长280 nm。结果:抗氧剂BHT的线性检测范围0.41~103.00μg·mL^(-1)(r^2=1.000),可提取硫的线性检测范围0.10~103.50μg·mL^(-1)(r^2=0.999 9),BHT和可提取硫的平均回收率分别为95.2%和86.8%。测定7批药用胶塞中BHT与可提取硫含量范围分别为4~206μg·g^(-1)和1~143μg·g^(-1)。结论:本文建立的检测方法经方法学验证,可用于考察药用丁基橡胶塞中BHT和可提取硫的含量及质量控制。展开更多
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.
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Results of oxidation 2-(N-acetylamine)-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionic acid oxygen depend on temperature. At 55℃?- 60℃, 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa is formed. The constitution is based on dates of spectrums 1Н and 13С NMR. At 95℃?- 97℃, mixtures of 2,4-di-tert-butylbicyclo(4,3,1)deca-4,6-dien-8-(N-acetylamine)-3,9-dion-1-oxa and of 6,8-di-tert-butyl-3-(N-acetylamine)spiro(4,5)deca-1-oxa-5,8-dien-2,7-dione are produced. Structures are calculated by the method of Hartrii-Foka. Values of enthalpies and of entropies allow to assume dynamic isomerism.
文摘The mixed-ligand complexes of molybdenum(VI) with dithiolphenols (DP) {2,6-dithiol-4-methylphenol (DTMP), 2,6-dithiol-4-ethylphenol (DTEP) and 2,6-dithiol-4-tert-butylphenol (DTBP)} in the presence of hydrophobic amines have been investigated by spectrophotometric method. The condition of complexing and extraction, physical-chemical and analytical characteristics of this complex have been found. As hydrophobic amine 2(N, N-dimethylaminomethyl)-4-methylrphenol (АP1) and 2(N, N-dimethylaminomethyl)-4-xlor-phenol (AP2), 2 (N, N-dimethylamino-methyl)-4-brom-phenol (AP3) were used. It has been found that mixed-ligand complex was formed in weakly acidic medium (pH 4.1 - 5.9). The maximum analytical signal when complexing Mo(V) is observed at 516 - 534 nm. The calculated molar absorption (εmax) belongs to the range (4.16 - 5.35) × 104. The Beer’s law was applicable in the range of 0.3 - 22 μg/ml. The extraction photometric methods of the molybdenum determination were processed. The influence of diverse ions on determination of molybdenum has been studied. The proposed method was applied successfully to determine amount of molybdenum in steel and in soil.
文摘目的:建立药用丁基橡胶塞中添加剂[抗氧剂264(2,6-二叔丁基-4-甲基苯酚,简称BHT)和硫化剂可提取硫]的含量测定方法。方法:以二氯甲烷-无水乙醇为提取溶剂,利用高效液相色谱法对药用丁基橡胶塞的BHT和可提取硫含量进行测定,以含0.1%三氟乙酸的乙腈-含0.1%三氟乙酸的水(90∶10)为流动相,流速1.0 m L·min^(-1),检测波长280 nm。结果:抗氧剂BHT的线性检测范围0.41~103.00μg·mL^(-1)(r^2=1.000),可提取硫的线性检测范围0.10~103.50μg·mL^(-1)(r^2=0.999 9),BHT和可提取硫的平均回收率分别为95.2%和86.8%。测定7批药用胶塞中BHT与可提取硫含量范围分别为4~206μg·g^(-1)和1~143μg·g^(-1)。结论:本文建立的检测方法经方法学验证,可用于考察药用丁基橡胶塞中BHT和可提取硫的含量及质量控制。