吸附树脂和活性炭对气体中苯的吸附研究

采用了动态吸附实验方法研究了吸附树脂NDA-201和椰壳型活性炭C1对苯蒸汽的吸附行为.对吸附平衡数据采用Dubinill-Astakov方程进行了拟合分析,并根据吸附剂孔结构特征探讨了吸附机理.实验结果表明,两种吸附剂的苯吸附等温线存在交叉现象,对高浓度苯蒸汽吸附治理可采用NDA-201树脂,低浓度则采用椰壳型活性炭C1;Dubinin-Astakov方程能用来对两种吸附剂的等温线进行拟合,表明吸附剂的微孔区域对吸附起着重要作用.微孔体积计算值的比较和特征曲线叠合的程度说明了.Polanyi吸附势理论更适合于描述椰壳型活性炭C1对苯的吸附,这可能是由于椰壳型活性炭C1的孔分布集中于微孔区,而NDA-201树脂除了微孔外还有一定量的中孔和大孔.     

梯形苯基/甲基聚倍半硅氧烷树脂的合成及热稳定性研究

以苯基三氯硅烷和甲基三氯硅烷为主要原料,以不同摩尔比(1:1,2:1,3:1)合成了三种梯形聚苯基/聚甲基倍半硅氧烷树脂(1～3),其结构经UV和IR表征.热重分析发现,1～3的热分解温度分别为470 ℃,517 ℃和540 ℃,说明随着苯基三氯硅烷与甲基三氯硅烷摩尔比增大,热稳定性增加.用量子化学方法计算发现苯基硅氧烷的C-Si键长比甲基硅氧烷C-Si键短,且更牢固.     

Synthesis and application of a highly efficient tetraester calix[4]arene based resin for the removal of Pb from aqueous environment

The present study describes the Pb²⁺ sorption potential of newly synthesized tetraester calix[4]arene (TC4) based resin from aqueous media. The TC4 resin was synthesized through diazotization reaction of TC4 with Amberlite XAD-4 in the presence of sodium nitrite in acidic medium. The TC4 resin was characterized by using different analytical techniques such as FT-IR, elemental analysis and scanning electron microscopy (SEM). The Pb²⁺ removal ability of the resin from the aqueous environment has been evaluated by both batch adsorption as well as column studies. The experiments have been conducted involving the determination of effect of pH, adsorbate concentration, adsorbent dosage, contact time and temperature. Moreover, on the basis of kinetic studies, the pseudo-first-order and pseudo-second-order adsorption kinetics were calculated. The thermodynamic parameters of lead adsorption were also calculated. Equation isotherms such as Langmuir (L), Freundlich (F), and Dubinin-Radushkevich (D-R) were successfully used to model the experimental data. From the D-R isotherm parameters, it was considered that the uptake of Pb²⁺ by TC4 resin is ion exchange mechanism. From the results it has been found that the TC4 resin is a versatile adsorbent for the removal of Pb²⁺ from the aqueous environment. The study also confers its impact on human health, reinstate of polluted sites and other fields of material science.     

含改性松香的丁二醇二缩水甘油醚固化反应动力学研究

设计了含改性松香无苯环的环氧固化体系和无松香的对照体系,分别是无松香体系Ⅰ：丁二醇二缩水甘油醚（BDGE）和甲基六氢苯酐（MeHHPA）;无规体系Ⅱ：丙烯酸松香（AR）、BDGE和MeHHPA;有规体系Ⅲ：丙烯酸松香基环氧树脂（ARE,由AR和BDGE预聚而来）和MeHHPA。对三体系的固化反应应用动态示差扫描量热仪（DSC）进行了研究,利用KAS法求得不同转化率下的表观活化能,通过整个反应过程反应活化能的变化,得到了三体系反应的内在机理,结果发现松香基的引入及引入顺序都对固化反应产生影响。     

环氧树脂增韧改性的研究进展

概述了近年来互穿聚合物网络（IPN）、刚性粒子增韧环氧树脂的研究现状,并展望了环氧树脂增韧改性研究的前景。     

Properties of methyltetrahydrophthalic anhydride‐cured epoxy resin modified with MITU

Methylimidazole‐terminated chain‐extended urea (MITU) containing polypropylene oxide spacer was synthesized and employed to modify epoxies composed of a diglycidyl ether of bisphenol‐A (E‐51) and methyltetrahydrophthalic anhydride (MTHPA). The curing behavior, viscoelastic property, impact response, and fracture surface morphology of the curing systems were systematically investigated. Differential scanning calorimeter (DSC) analysis reveals that the curing reactivity of the epoxy system is greatly enhanced with the addition of MITU. From the dynamic mechanical analysis, besides the low‐temperature β relaxation, shoulder at higher temperature side appears for the MITU‐modified systems. Meanwhile, the addition of MITU leads to the increase of loss factor (tan δ) over the temperature range of 0–75°C. Impact tests show that the modifier can be effective in toughening the epoxy resin at relatively low loading, and the scanning electron microscope (SEM) images of the fracture surface for the modified systems display signs of ductility. Copyright © 2008 John Wiley & Sons, Ltd.     

Spectrophotometric determination of 4,6-dinitro-o-cresol (DNOC) in soil and lemon juice

Although the use of once widely applied selective herbicide, 4,6-dinitro-o-cresol (DNOC), was cancelled by US-EPA in 1987, it is still found in soil and water due to its slow degradation in the environment. Since solid phase extraction-spectrophotometry combinations are much simpler and cheaper than chromatography/MS based methods and most routine laboratories lack such sophisticated instrumentation, it is desirable to establish novel sensitive, well-established, and field-applicable spectrophotometric methods for the rapid assay of DNOC in water and soil. For this purpose, two distinct spectrophotometric methods utilizing the periodate and copper(II)-neocuproine (Nc) reagents have been developed following Zn/HCl reduction of the pesticide in a microwave oven for 15 s, and validated for DNOC determination at mg L⁻¹ level. The LOD values were 1.6 and 0.2 mg L⁻¹ for periodate and Cu(II)-Nc methods, respectively. Statistical comparison of the developed methods was made with the aid of high performance liquid chromatography (HPLC) equipped with a C₁₈ (5 μm), 250 mm× 4.6 mm ID reversed phase column in conjunction with a UV (264 nm) detector, and a methanol (HPLC grade) +0.1% glacial acetic acid mixture mobile phase. Both spectrophotometric methods were directly applicable to soil since they were not interfered with common soil cations and anions, together with some pesticides. These methods were applied to real samples such as synthetically contaminated montmorillonite and lemon juice, and overall recovery efficiencies at the order of 95% or greater were achieved in the devised adsorption/elution procedures. An 8-hydroxyquinoline (oxine)-impregnated XAD copolymer resin stabilized with Fe(III) salt was used to preconcentrate DNOC at a concentration factor of 20 from lemon juice contaminated with 1 mg L⁻¹ DNOC, and the analyte retained at pH 2.5 was eluted with 0.025 M methanolic NaOH. Both the devised spectrophotometric methods and the proposed preconcentration column with optimized sorption and desorption conditions are novel for DNOC assay in the natural environment.     

铀水冶厂贫树脂转型试验研究和应用

用H2SO4作转型剂对贫树脂转型,进行了小试和生产实际应用,结果表明,H2SO4可以把贫树脂中的Cl-转下来,并返回到淋洗工序利用,降低了淋洗工艺中NaCl的消耗,降低了尾液Cl-浓度,减少了铀的损失和废水排放量,降低了吸附尾液铀浓度,实现了节能减排的目的.     

蒸汽驱用碱木素高温冻胶交联剂的研制及评价

碱木素冻胶是一种具有热稳定性且易于进入地层深部的高温堵剂,首先合成了碱木素冻胶的交联剂——水溶性酚醛树脂,优化了其合成反应条件,然后评价了碱木素高温冻胶的性能.研究结果表明:水溶性酚醛树脂的最佳合成条件为催化剂NaOH质量分数9%,甲醛与苯酚摩尔比1.8,反应温度85℃,自缩聚反应时间30 min.脱水后的水溶性酚醛树脂中羟甲基质量分数为83.54%,游离醛质量分数为0.35%,黏度为2 950 mPa.s,可在25℃下保存1个月,贮存稳定性好.在酚醛树脂质量分数为3.5%、碱木素质量分数为10%、体系pH值为9.75、高温200℃条件下碱木素冻胶的成胶时间为1.5 h,冻胶强度为0.092 MPa.成胶时间短,冻胶强度高,热稳定性好,具有较好的蒸汽调驱性能和应用前景.     

热塑性塑料对环氧树脂冲击性能及热性能的影响

采用聚碳酸酯(PC)、聚醚酰亚胺(PEI)和聚对苯二甲酸丁二醇酯(PBT)3种热塑性塑料改性环氧树脂,研究了不同热塑性塑料对环氧树脂在低温(77 K)及室温下的冲击性能及热性能的影响。研究结果表明:相对于纯环氧树脂,PEI、PC和PBT改性环氧树脂在77 K时的冲击强度分别提高了50.7%、36.4%和30.7%,在室温下的冲击强度分别提高了58.5%、39.2%和28.9%;PEI、PC和PBT改性环氧树脂及纯环氧树脂在-150℃的储能模量分别为5025 MPa、4733 MPa、4539 MPa和3853 MPa;相对于纯环氧树脂,PEI、PC和PBT改性环氧树脂的起始热失重温度分别提高了14℃、10℃和7℃。表明热塑性塑料可提高环氧树脂的冲击性能和热稳定性。