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121.
New segmented aromatic poly(ether sulfone)-amide and poly(ether sulfone)-imide copolymers were synthesized by the chain extension of α,w-diamine-terminated poly(ether sulfone) oligomer with both aromatic dicarboxylic acid chlorides and tetracarboxylic dianhydrides, respectively. Crystallization of the poly(ether sulfone)unit was suppressed by the introduction of amide or imide linkage along the polymer backbone, giving amorphous copolymers that were +eadily soluble in various organic solvents. The copolymers had somewhat higher glass transition temperatures than the parent poly(ether sulfone). They afforded transparent and tough films by solution casting. © 1992 John Wiley & Sons, Inc.  相似文献   
122.
胺型键合反相固定相的制备及评价   总被引:2,自引:0,他引:2  
首次将一种新型硅烷偶联剂--β-(3,4-环氧环已基)乙基三甲氧基硅烷(β-ECTS)与辛胺反应,然后再键合到硅胶上,得到了胺型键合固定相,并用元素分析、^13C固体核磁共振、红外光谱进行了表征。以甲醇和水为二元流动相,用包括碱性、酸性和中性有机化合物在内的混合物对该固定相进行评价,并考察了该填料的适用pH范围及水解稳定性。结果表明,该固定相具有较好的色谱性能,且在pH=2-8之间稳定性能良好,可有效地用于碱性化合物的分析分离。  相似文献   
123.
By using the relationship equation of Partition coefficients with water solubilities for polycyclic aromatic hydrocarbons (PAHs), we have estimated the solubilities of PAHs. In addition the high-performance liquid chromatograph (HPLC) method has been used for the indirect determination of solubilities of PAHs. t3ased on the di-region theory, We have studied the relationship of the solubilities of PAHs with carcinogenicity and introduced the solubility parameter into the di-region theory equation. The calculated carcinogenicity of PAHs from the obtained equation shows little difference from that calculated from Dai Qianhuan's equation.  相似文献   
124.
The crystalline morphology of a thermotropic aromatic polyester has been studied by microscopy techniques. Spherulites with ringed structure under polarizing micioscope were observed for solution cast specimens, They were composed of radially growing crystalline lamellae of thickness around 100. It was found that the molecules were packed in the thickness direction. Banded texture was observed in randomly packed domains for melt cast specimens. The bands have the same width and internal structure as those usually observed in oriented specimens of these polymers obtained by shearing their mesomorphic melt.  相似文献   
125.
合成了七个未见文献报道的双环[2,2,1]庚-5-烯-2-甲酰基芳香醛腙席夫碱 类化合物。用核磁共振氢谱、红外光谱和元素分析对新化合物进行了表征,考察了 它们的生物活性。结果表明某些化合物具有除草作用、抗菌作用和植物生长调节作 用。  相似文献   
126.
Summary Lithium chloride (LiCl) effect on the retention process of a phenol derivative series was investigated on two types of fluorinated stationary phase (i.e. a silica grafted with fluorinated linear alkyl chain (L-FSP) and a silica grafted with fluorinated aromatic ring stationary phase (A-FSP)). The results showed that the solute retention is enhanced when the A-FSP was used instead of the L-FSP due to additional – interactions. For the two fluorinated stationary phases (FSPs), the phenol-FSP association process can be divided into two LiCl concentration domains demonstrated that it was important to take into account the adsorbtion of Cl anion on the FSPs. As well, enthalpy-entropy compensation revealed that the solute retention mechanism was independent of the solute molecular structure and confirmed a change on the solute retention mechanism at a critical LiCl concentration value around 0.02M.  相似文献   
127.
于泓 《分析化学》1998,26(1):89-92
研究了邻苯二甲酸、苯甲酸和对羟基苯甲酸3种芳香酸分别做淋洗液的单柱阳离子色谱法分离测定Li+、Na+、NH4+、K+、甲胺、乙胺和正丙胺7种物质。3种芳香酸做淋洗液均可将7种物质分离开,且分离结果差异不大。在淋洗液浓度相同的条件下,邻苯二甲酸做淋洗液测定的检出限较低。选择3.0 mmol/L邻苯二甲酸做淋洗液测得了上述7种物质的检出限和线性范围,并进行了叶面肥试样分析,7种物质的加标回收率在96.4%~98.6%之间。  相似文献   
128.
1. INTRODUCTION When investigating contaminated sites it is often essential to determine specific pollutants in a large number of ambient air samples. Amongst these sites, polycylic aromatic hydrocarbons (PAHs) are a major class of compounds that hav…  相似文献   
129.
The Sakurai reaction of N-alkoxycarbonylamino sulfones with allyltrimethylsilane in the presence of a catalytic amount of indium(III) chloride at room temperature produces the corresponding protected homoallylic amines in high yields.  相似文献   
130.
The kinetic features of radical polymerization of styrene in the presence of primary and secondary aliphatic amines combined with benzoyl peroxide and the molecular-mass characteristics of the resulting polymers were studied. In the presence of peroxide initiators, aliphatic amines, as potential sources of stable aminoxyl radicals, provide the synthesis of polystyrene with a controlled molecular mass without gel effect at a relatively high rate. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 159–164, January, 2007.  相似文献   
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