悬浮法合成聚丙烯腈高吸水性树脂

以偶氮二异丁腈为引发剂，用悬浮聚合法合成了交联聚丙烯腈，然后对其进行水解，得到了高吸水性聚丙烯腈。交联剂用量和水解条件对树脂吸水倍数的影响很大。树脂吸去离子水倍数为420倍，平均粒径为250μm。     

高效液相色谱法测定卷柏中的穗花杉双黄酮

用反相高效液相色谱法测定卷柏提取物中的穗花杉双黄酮。结果表明：穗花杉双黄酮在质量浓度为41.2mg／L～206mg／L时，峰面积Y与其质量浓度X的线性关系良好，回归方程为Y=547．028X 15．4895(r=0.9999)，最低检测限为2．0μg/L；穗花杉双黄酮的平均回收率为99．42％(n=3)，相对标准偏差RSD为0．79％；连续进样、日内进样和日间进样所得检测结果的RSD分别为0．12％、0．11％和0．11％。     

中央空调的水处理

本文扼要介绍了中央空调循环冷却水和冷冻水系统中常见的问题及其原因,并对冷却水和冷冻水的处理程序作了初步的阐述.     

反相高效液相色谱法测定meso-四苯基卟啉钴的纯度

采用反相高效液相色谱法测定合成meso-四苯基卟啉钴的纯度;以甲醇乙腈二氯甲烷(体积比为55∶35∶10)为流动相,ShimpackCLCODS柱(150mm×6.0mmi.d,5μm)为分离柱,流速为1.5mL/min,检测波长420nm;meso四苯基卟啉钴的测定在1.0～10μg/mL时线性关系良好(相关系数r=0.9993),加标回收率为97.03%～101.42%,重复进样的相对标准偏差RSD为0.64%～2.92%(n=5)。方法的准确度高,精密度好,实际应用效果好。     

High temperature polymerization of propylene catalyzed by MgCl2‐supported Ziegler–Natta catalyst with various cocatalysts

Four cocatalysts, referred to as ethylaluminoxanes, were synthesized by the reaction between triethylaluminium (AIEt₃) and water under various molar ratios of H₂O/Al at ?78°C. Aluminoxanes were used as cocatalysts for a MgCl₂‐supported Ziegler–Natta catalyst for propylene polymerization at temperatures ranging from 70 to 100°C. When the polymerization was activated by AlEt₃, the activity as well as the molecular weight and isotacticity of the resulting polymer gradually dropped as the temperature varied from 70 to 100°C. When ethylaluminoxane was employed as the cocatalyst, good activity and high molecular weight and isotacticity were obtained at 100°C. Furthermore, when the cocatalyst varied from AlEt₃ to ethylaluminoxane, the atactic fraction and polymer fraction with moderate isotacticity decreased and the high isotactic fraction slightly increased, which indicated that the variation of the cocatalyst significantly affects the isospecificity of active sites. It was suggested that the reactivity of the Al‐Et group and the size of the cocatalyst were correlated to the performance of the Ziegler–Natta catalyst at different temperatures. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1978–1982, 2006     

碳钢贮热水箱的模拟腐蚀试验及涂层耐蚀性能研究

碳钢贮热水箱长期在30～80°C温变的热水环境中工作,易受到热水及水中杂质的腐蚀。研究了不同温度下Q235钢在自来水及含100μg/mLNaCl的自来水中的腐蚀速率。对裸钢及其涂覆相同厚度的不同涂层──酚醛环氧(自制)、钛纳米聚合物和改性聚乙烯后在70°C自来水中的极化曲线进行了比较。采用动电位扫描极化曲线测量和电化学交流阻抗谱法(EIS)分别对涂覆不同涂层的Q235钢进行了耐蚀性能研究。结果表明,3种防腐涂层均具有较佳的抗热水性,耐蚀能力较强,适宜对Q235钢贮热水箱进行防护。     

15%田草灵高效液相色谱分析

采用Ｎｏｖａ－Ｐａｋ Ｃ１８不锈钢色谱柱进行反相液相色谱分析，以甲醇：水＝６５：３５（Ｖ／Ｖ）为注动相，以邻苯二甲醇二乙酯为内标物，用内标法测定田草灵除草剂中苄嘧黄隆和异丙甲草胺的含量，结果表明，各有效成分与内标物色谱峰分离完全，杂质无干扰，测定结果，苄嘧黄隆和异丙甲草胺的变异系数分别为０．７４％和１．０７％，回收率分别为９９．４％￣１００．８％和９９．１％￣１０１．３％。     

汽车工业生产用热熔胶膜的研制

介绍了汽车工业生产内装饰复合材料用热熔胶膜的性能及其研制状况。这种热熔胶膜具有使用便捷,高效,生产、使用过程中没有污染的具有热熔胶膜的特长。