THE SYNTHESIS AND CHARACTERIZATION OFSOME POROUS RESINS AND THEIR ADSORPTIONPROPERTY ON STEVIA GLYCOSIDES

1.INTRODUCTIONFromtheleavesofSteviaRebaudianaBertoni,asweetherbindigenoustoelevatedterrainonthebordersofBrazilandParaguay,eightsteviaglycosideshasbeenisolatedinayieldof10~15%andutilizedasahigh-sweetness,low-calorie,nonnutritionsweetener[1-3].Stevioside,rebaudiosideAandrebaudiosideCarepresentinthelargestquantitiesoftheeightsteviaglycosides.Amongthesethreeglycosides,rebaudiosideAisknownasthebestsweetenerwithrespecttotheintensityofsweetnessaswellasthequalityoftaSte,whiletheothertwomajorsw…     

CHLOROMETHYLATION OF POLYMERS MADE FROM TECHNICAL DIVINYLBENZENE AND PROPERTY OF THE CHLOROMETHYLATED POLYMERS

1. INTRODUCTIONMacroporous polymers of technical divinylbenzene are often used as polymeric adsorbents for adsorptive separation. These resins may be advantageous compared to other polymeric adsorbents due to the high specific surface area and high porosity. However, the ability of these resins to adsorb polar compounds is very weak because the resins are non-polar and the values of the swelling capacity in aqueous solution are relatively low, and thus these resins are limited for adsorpti…     

超高交联聚苯乙烯吸附剂的合成,结构与性能

本文总结了超高交联聚苯乙烯的各种合成方法，对干态下和溶胀态下超高交联聚苯乙烯的结构进行了评述，并介绍了超高交联聚苯乙烯独特的溶胀性能和优良的吸附性能．引用参考文献３２篇。     

大孔球形纤维素离子交换剂的制备及其对蛋白质的吸附富集性能研究.Ⅱ.球形纤维素的交联活化及功能基化研究

本文考察了球形纤维素交联活化的影响因素。结果表明，碱浓度为4～5mol／L，温度75℃，反应时间30min，为最佳交联条件；室温下，碱浓度1mol／L左右反应8h则为最佳活化条件。     

酚醛型吸附树脂对VB_(12)的吸附性能研究

研究了酚醛型吸附树脂JDW 1、JDW 2 (自制 )和DuoliteS 76 1对VB12 的静态和动态吸附 .结果表明 ,JDW 1对VB12 的吸附量达 84mg g ,明显优于DuoliteS 76 1;吸附VB12 的初始阶段 ,即达到 4 3%～6 9%平衡吸附时 ,吸附速率数据和半经验速率方程很吻合 ;酚醛型吸附树脂等温吸附VB12 的平衡吸附数据符合Langmuir方程 ,相关系数在 0 99以上 ,因此 ,酚醛型吸附树脂吸附VB12 属单分子层吸附 ;在动态条件下 ,用含甲醇 80 %溶液以 1 1BV h来洗脱吸附VB12 的JDW 2 ,在 4 2、6 4个床体积的洗脱率分别是 92 2 0 %、95 93% ,这表明酚醛型吸附树脂具有良好的洗脱性能 ,用含甲醇为 80 %溶液作洗脱剂从JDW 2洗脱VB12 ,效果很好     

重结晶法分离精制莱鲍迪甙A的研究

用甲醇、异丙醇和水不同比例的混合溶剂对甜叶菊糖以及分离出甜菊甙的母液浓缩物分别进行重结晶研究，考察了甜菊甙和莱鲍迪甙A的结晶分离及菜鲍迪甙A结晶纯化的最佳条件，得到了高纯度的莱鲍迪甙A，并对其进行了熔点测定和HPLC表征，为莱鲍迪甙A的分离与纯化提供了一种简便的方法。     

高度交联聚苯乙烯吸附剂的结构与吸附性能研究

在通过Ｆｒｉｅｄｅｌ—Ｃｒａｆｔｓ后交联反应制备高度交联聚苯乙烯吸附剂的过程中，向反应体系中加入非极性芳香化合物甲苯，当加入少量甲苯时，吸附剂的比表面积、孔容等变小，但其吸附能力却明显提高；当加入甲苯超过某一量时，其吸附能力又随加入甲苯的量的增加而降低，这说明孔结构和骨架结构共同影响着高度交联聚苯乙烯吸附剂的吸附性能．     

采用Nafion粘结剂的PEMFC氧电极研究

研究了聚合物电解质燃料电池（PEMFC）中以Nation溶液取代PTFE乳液作粘结剂的效果．并对催化剂层内Nafion含量进行了优化，同时探讨了气体工作压力和离子交换膜的影响，实验发现：1．使用Nafion溶液后显著提高电池性能，Nafion含量为2mg·cm－2时性能技好；2．气体压力增大改善了电池位能；3．使用Nafion115膜的电池性能优于使用Nafion117膜的电池．要进一步提高电池性能，减小欧姆控制区的斜率是必要的．     

INVESTIGATION OF THE FRIEDEL-CRAFTS REACTION OF THE CHLOROMETHYLATED COPOLYMER OF STYRENE-DIVINYLBENZENE

In the presence of Friedel-Crafts catalyst, the chloromethylated copolymer of styrene-divinylben-zene may react with each other and cross-link by itself Thus a new type of polymeric adsorbent wasobtained, and its structure was identified by its physical properties and infrared spectra. The Friedel-Crafts reaction is manifestly affected by the nature of the solvent, the kind and amount of catalystused, reaction temperature and reaction time, etc. The porous structure and physical properties of the adsorbent prepared have been investigatedsystematically. The adsorbent has high specific surface area (1000--1300m~2/g), porosity, narrowpore distribution,high skeleton density and good mechanical properties.     

CHLOROMETHYLATION OF POLYMERS MADE FROM TECHNICAL DIVINYLBENZENE AND PROPERTY OF THE CHLOROMETHYLATED POLYMERS

The goal this paper was to reveal the feasibility of chloromethylation of polymers made from technical divinylbenzene so as to introduce functional groups into polymeric adsorbents.Forthis study,the factors,that effect the chloromethylation reaction,such as the pore structure of the polymer,the ratio of the reactants to catalyst,the reaction temperature and reaction time and so on were investigated.and the pore structure and property of the chloromethylated polymers were studied.The results showed that polymers of technical divinylbenzene could be chloromethylated successfully,and the adsorptive property of the chloromethylated resin was different from that of the initial resin.