GDX 502管吸附-二氯甲烷解吸-气相色谱法测定气中的吡啶

建立了GDX 502管吸附-二氯甲烷解吸-气相色谱测定气中吡啶的方法,考察吸附管类型、解吸溶剂、解吸溶剂体积、采样时间和采样流量对测定结果的影响。结果表明,气中吡啶用GDX 502吸附管以0. 5 L/min的流量采样20 min,二氯甲烷解吸至1 m L,DB-1 (30 m×250μm×0. 25μm)柱分离,空白样品低、中、高3种加标量回收率为90. 8%～108%(n=6),相对标准偏差为2. 9%～4. 4%,方法在0～19. 6 mg/L线性范围内响应良好,相关系数(r)=0. 999 9。当采样体积为10 L时,检出限为0. 01 mg/m~3。该方法重复性好、回收率高、干扰较小,能够满足空气和废气中吡啶分析的要求。     

Spectrophotometric analyses of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in water

A simple and accurate spectrophotometric method for on-site analysis of royal demolition explosive(RDX) in water samples was developed based on the Berthelot reaction. The sensitivity and accuracy of an existing spectrophotometric method was improved by:replacing toxic chemicals with more stable and safer reagents; optimizing the reagent dose and reaction time; improving color stability; and eliminating the interference from inorganic nitrogen compounds in water samples. Cation and anion exchange resin cartridges were developed and used for sample pretreatment to eliminate the effect of ammonia and nitrate on RDX analyses. The detection limit of the method was determined to be 100 μg/L. The method was used successfully for analysis of RDX in untreated industrial wastewater samples. It can be used for on-site monitoring of RDX in wastewater for early detection of chemical spills and failure of wastewater treatment systems.     

Electro-assisted regeneration of ion exchange resins

Electro-assisted regeneration (EAR) for the mixed bed of strongly acidic cation and weakly basic anion exchange resins with the Al(OH)3 suspension in a three-compartment cell was investigated. The desalination experiments were carried out to evaluate the characteristic of the regenerated mixed resins. Experimental results showed that the efficiency of resin regeneration was strictly dependent on the voltage, regeneration time, and feed regenerant flow rate. The amount of the effluent reached 50 times the volume of the resins bed, and the conductivity was less than 1.0 μs/cm. Compared to the conventional ER, the total effluent volume of EAR was about 1000 mL more than that of ER under the same conditions, and the outlet conductivity was significantly lower. The desalination and regeneration reaction mechanisms of the mixed resins indicated the regeneration efficiency of resin with Al(OH)₃ as the regenerant was much higher than that with H₂O.     

阳离子交换树脂微柱分离测定矿石中锆的研究

建立了HD-8阳离子交换树脂微色谱柱分离富集矿石中锆的方法。研究了上柱酸度、淋洗液、洗脱液、干扰离子等对锆的吸附性能的影响。结果表明,上柱最佳酸度0.5~2 mol/L HCl、淋洗液1 mol/L HCl、洗脱液1 mol/L H2SO4,锆的吸附与洗脱效果最好。选用邻氯苯基荧光酮为显色剂,直接在硫酸介质中显色,胶束增溶光度法测定,操作简便,灵敏度高,选择性好。树脂的吸附容量为81.4 mg/g。与常规柱相比,微色谱柱吸附后,洗脱体积减少了16倍,柱效高,分离速度快,试剂用量少,灵敏度高。该方法可以用于实际矿石的分离测定,经标准值验证,测定值与标准值相近,多次平行测定后,方法的相对标准偏差为1.9%~2.7%,说明此法可用于分析实际样品。     

110离子交换树脂担载催化剂净化低浓度PH3

以110丙烯酸系阳离子交换树脂作为载体,Pd(Ⅱ)-Cu(Ⅱ)为主催化剂,制成担载型过渡金属催化剂。以N₂为载气,对反应温度、氧含量、催化剂用量3个因素进行催化氧化净化低浓度PH₃研究。实验结果表明,在氧含量为3.7%,温度为72℃时,催化剂的催化活性较高;PH₃净化效率随催化剂用量增大而提高。在优化后的实验条件下,考察催化剂以CO为载气时催化剂对PH₃的净化效率,虽然净化效果比以N₂为载气时差,但反应较稳定,持续时间较长,有较好的抗杂毒性,且催化剂具有再生性能。     

110离子交换树脂担载催化齐净化低浓度PH3

以110丙烯酸系阳离子交换树脂作为载体，Pd（Ⅱ）-Cu（Ⅱ）为主催化剂，制成担载型过渡金属催化剂。以N2为载气，对反应温度、氧含量、催化剂用量3个因素进行催化氧化净化低浓度PH3研究。实验结果表明，在氧含量为3．7％，温度为72℃时，催化剂的催化活性较高；PH3净化效率随催化剂用量增大而提高。在优化后的实验条件下，考察催化剂以CO为载气时催化剂对PH3的净化效率，虽然净化效果比以N2为载气时差，但反应较稳定，持续时间较长，有较好的抗杂毒性，且催化剂具有再生性能。     

超临界CO_2流体环境中线路板分层实验分析

在超临界CO2流体环境下,当温度达到240℃以上时,印刷线路板就会发生分层现象。同时,在实验中发现在非超临界流体环境下,当温度达到260℃以上时,线路板也会发生分层现象。从线路板粘接材料发生热解反应的角度出发,在对比超临界CO2流体环境下与非超临界流体环境下的线路板分层效果的基础上,对超临界CO2流体环境下的线路板分层做出合理分析,最后发现临界CO2流体对线路板分层过程有促进作用,并对其分层效果有优化作用。     

不同复苏方法对阴树脂复苏效果的影响研究

研究了直接酸洗复苏法、树脂转为氯型后酸洗复苏法、氯化钠转型后用次氯酸钠氧化复苏法、次氯酸钠氧化后用盐碱混液复苏法、双氧水氧化后用盐碱混液复苏法等五种不同的复苏方法对铁和有机物污染树脂复苏效果的影响。结果表明：复苏方法不同时，亚铁离子污染树脂的复苏效果和铁离子污染树脂的复苏效果是不相同的，同时可看出，双氧水氧化后盐碱混液复苏法复苏铁污染树脂的效果最好；五种不同的复苏方法对腐植酸污染的树脂都有较好的复苏效果，且复苏效果相差不大。     

Adsorption of phenolic compounds from aqueous solutions by aminated hypercrosslinked polymers

Two novel polymers （NJ-1 and N J-2） were synthesized by chemically modified a hypercrosslinked polymer NJ-0 with dimethylamine and trimethylamine, respectively. The comparison of the adsorption properties of the three polymers toward phenol, resorcin and phloroglucin was made. The study focused on the static equilibrium adsorption behaviors and the adsorption thermodynamics. Freundlich equation was found to fit the adsorption results well. The effect of amino groups introduced onto the surface of the resin and the structure of phenolic compounds on the adsorption were also studied. The hydrogen-bonding interaction and electrostatic interaction could happen between the amino groups and the adsorbates. The adsorption impetus increased as quantity of hydroxyl groups increased, but the adsorption capacity decreased due to the drop of the matching degree of the aperture of resins and the diameter of adsorbate molecules.     

Aminolysis and aminoglycolysis of waste poly(ethylene terephthalate)

This paper describes the chemical degradation of waste poly(ethylene terephthalate) (PET) with polyamines or triethanolamine, the characteristics of the products, and a search for ways to use these products. Solvolysis of the polymer ester bonds was caused by diethylenetriamine, triethylenetetramine, and their mixtures, as well as mixtures of triethylenetetramine and p-phenylenediamine or triethanolamine. Products of aminolysis or aminoglycolysis of PET obtained in reactions performed at 200–210°C (with a molar ratio of the recurrent polymer unit to amine of 1 : 2) have been characterized using nuclear magnetic resonance (NMR). Viscosity and hydroxyl number measurements have been done for PET/triethanolamine products. Substances from aminolytical reactions with polyamines were tested as hardeners for liquid epoxy resins, and the product of polymer aminoglycolysis with triethanolamine was tested as an epoxy resin hardener, e.g., for water-borne paints, and a polyol component for rigid polyurethane foams. The compositions of epoxy resin hardeners have been characterized using DSC and rheometry. Comparative analyses of the hardened epoxy materials have been done on the basis of glass temperature and mechanical properties data, as well as some specific properties of the coating materials and rigid polyurethane foams. Received: September 15, 2000 / Accepted: September 21, 2000