高岭土-聚丙烯酸钠-聚乙烯醇复合吸水树脂的研究

以N,N-亚甲基双丙烯酰胺为交联剂、过硫酸铵/硫代硫酸钠为氧化还原引发剂、以环己烷为溶剂,采用溶液聚合法合成出高岭土-聚丙烯酸钠-聚乙烯醇复合吸水材料.研究了高岭土的添加量、交联剂的用量对复合树脂的吸水性、吸水速度及吸盐性等的影响.     

高岭土-聚乙烯醇高吸水性复合树脂的合成及性能研究

高吸水树脂属于新型功能高分子材料，其应用广泛．我国主要研究对象是淀粉接枝丙烯脂和丙烯酸盐系，聚乙烯醉(PVA)系高吸水树脂只有少数单位进行过研制．章采用悬浮聚合法，以顺丁烯二酸酐为交联剂，添加来源广泛、价格非常低廉的高岭土，制得了聚乙烯醇高吸水性复合树脂．该树脂的吸水倍率和吸盐水倍率分别为256和29倍．通过实验，讨论交联剂用量、高岭土添加量、水解程度等因素对吸水性能的影响．并对树脂吸水速率和保水性能进行实验．     

响应面优化香蕉茎纤维-丙烯酰胺高吸水树脂的制备工艺

以香蕉茎纤维和丙烯酰胺为原料,过硫酸钾和亚硫酸钠为引发剂,制备了香蕉茎纤维-丙烯酰胺高吸水树脂.在单因素实验的基础上,以树脂吸水率为响应值,选取酰纤比、反应温度、引发剂用量和交联剂用量为自变量,利用Box-Behnken设计和响应面法对各自变量及其交互作用对树脂吸水率的影响进行了研究,得到了二次多项式回归方程模型.香蕉茎纤维-丙烯酰胺高吸水树脂的最佳制备工艺条件为:酰纤比9.9 g/g、反应温度48℃、引发剂用量1.9%和交联剂用量0.18%.在此条件下,测得所制备的吸水树脂吸水率为461.22 g/g,与预测值相对误差为0.68%,说明响应面优化香蕉茎纤维-丙烯酰胺高吸水树脂的制备工艺具有较高的准确性与可靠性,该方法可用于香蕉茎纤维-丙烯酰胺高吸水树脂制备工艺的优化.     

废报纸制取吸水树脂研究

以废报纸为原料,经脱墨、碱煮、酸煮可得纤维素,以N,N-亚甲基双丙烯酰胺为交联剂,过二硫酸钾为引发剂,与丙烯酸接枝共聚制备了吸水树脂。讨论了原料单体配比、交联剂用量等因素对吸水树脂性能的影响,考查了制得的吸水树脂对蒸馏水、自来水和一定浓度NaCl溶液的吸收性能。在最佳条件下制得的吸水树脂对蒸馏水的吸水倍率为340 g/g,对自来水的吸水倍率为280 g/g,对0.05 mol/L NaCl溶液的吸水倍率达50 g/g。     

ATBS／AA／AM三元共聚超强吸水剂的合成与吸水率

利用 Span6 0作为分散剂 ,环己烷为有机相 ,用甲叉双丙烯酰胺交联及过硫酸铵引发 ,在反相悬浮液中合成了A TBS/ A A/ AM三元共聚超强吸水剂 .研究了它的吸水性能与共聚物的组成、交联剂用量和中和度之间的关系 .结果表明 ,加入 2 -丙烯酰胺 -2 -甲基丙磺酸单体后 ,共聚物胶在不同溶液中的吸水倍率有明显提高 .此外 ,考察了 p H和温度对共聚物胶吸水率的影响 .     

阳离子型环氧-丙烯酸酯-硅氧烷复合乳液的制备与性能

用接枝共聚法合成了可自交联的阳离子型水性环氧-丙烯酸酯-硅氧烷复合乳液,研究了环氧树脂种类、交联剂DMAEMA用量及硅氧烷对乳液及其涂膜性能的影响,用FTIR、DSC及TGA对聚合物的结构进行了分析。结果表明,以E20/E12为原料,所得乳液储存稳定;交联剂DMAEMA及硅氧烷的引入可以明显的提高共聚物膜的耐水、耐酸和耐溶剂性能。     

亚硫酸氢钠-锌粉漂白高岭土工艺研究

采用亚硫酸氢钠-锌粉漂白茂名地区的高岭土,研究了高岭土漂白的工艺条件。实验结果表明,亚硫酸氢钠和锌粉的加入量分别为高岭土质量的1．0％和0．25％、矿浆的pH值为1．5—2．0、矿浆质量分数为27％、漂白时间为20min时,高岭土白度由原矿的72％提高到84％。与保险粉漂白工艺相比,在漂白效果相同的情况下,可节约药剂成本25％以上。     

葡甘聚糖-壳聚糖-聚乙烯醇肥料包膜的结构表征及性能研究

以甲醛作交联剂,用溶液共混法制备了葡甘聚糖-壳聚糖-聚乙烯醇缓释肥料包膜,采用红外光谱(FT-IR)、X-射线衍射(X-RD)表征了膜的结构.同时测定了包膜的抗张强度、断裂伸长率、溶胀性.结果表明:交联膜中原料之间产生了较强的相互作用,形成了一个较稳定的复合体.     

反相悬浮法制备AA—AM共聚强吸水树脂

采用反相悬浮法制备了丙烯酸—丙烯酰胺共聚强吸水树脂,并考察悬浮剂、引发剂、交联剂、单体配比、丙烯酸中和度、油水比和聚合温度对聚合体系稳定性及树脂吸水率的影响.     

反相悬浮聚合法AA-AM吸水树脂的研究

采用反相悬浮聚合法,以丙烯酸和丙烯酰胺为主要原料,司班60等作为分散剂,环己烷为介质,过硫酸钾-亚硫酸氢钠为引发剂,N,N’-亚甲基双丙烯酰胺为交联剂,合成吸水树脂;考察了防粘剂、分散剂对树脂性能的影响,并对树脂的各种性能进行了分析。实验表明:丙烯酸和丙烯酰胺的单体摩尔比为1∶1.5,水油比为1∶4,引发剂0.7%(质量分数),交联剂0.06%(质量分数),分散稳定剂8%(质量分数),防粘剂PEG-2000和PEG-6000比为1∶1,丙烯酸与氢氧化钠的中和度为75%,反应温度控制在60℃,反应时间为1.5 h,在此条件下,树脂吸水率达870g/g。     

发泡聚乙烯醇（PVOH）吸液性能研究

在恒温恒湿条件下对发泡聚乙烯醇（PVOH）试样吸收水、酒精的特性进行了测试分析．结果表明：发泡PVOH试样在承受一定压力的情况下吸水性能略有降低;试样被压缩至8000N后平衡吸水量明显升高;试样自然吸收酒精量约为自然吸水量的5．2倍;吸收酒精后,试样尺寸约增加了20％;压缩至8000N后,再做吸酒精试验,其平衡吸酒精量基本不变,且达到吸收平衡的时间缩短．     

SDS改性沸石吸附亚甲基蓝的研究

以表面活性剂十二烷基硫酸钠(SDS)对沸石进行改性,改性后的沸石对亚甲基蓝溶液进行吸附,以紫外可见分光光度计分析最佳吸附条件。实验结果表明:SDS改性沸石吸附亚甲基蓝的最佳投入量为0.2 g;平衡时间为25 min;随着亚甲基蓝溶液的初始浓度增大,吸附量增大;溶液中其他阳离子存在竞争吸附。吸附过程可用伪二级反应动力学方程来描述,吸附活化能较小,主要为物理吸附过程。     

载铁改性沸石吸附剂去除含氟水中氟离子的研究

研究了用三氯化铁改性的沸石在水中的除氟性能．对使用条件及除氟机理进行了研究．并对洗脱、再生后的吸附荆进行吸附柱实验．结果表明，该吸附剂对含氟水中的氟具有吸附容量高、速度快、选择性高、易洗脱再生的特性．多次洗脱再生后的吸附剂可重复使用，吸附剂性能稳定，吸附剂机械强度高．该吸附剂的静态饱和吸附容量可达26．57mg(F^-)／g(吸附剂)．     

微波辐射下淀粉丙烯酸接枝共聚反应

在微波辐射下探讨了玉米淀粉与丙烯酸流变相态的接枝共聚反应，考察了辐射时间、淀粉预糊化温度、引发剂浓度、丙烯酸中和度等因素对聚合反应及聚合物吸水率的影响．结果显示，微波辐射可以得到较高接枝率的玉米淀粉丙烯酸共聚物．     

Absorption of NO2 into Na2S solution in a stirred tank reactor

To understand the absorption mechanism of nitrogen dioxide into a sodium sulfide solution, a stirred tank reactor with a plane gas-liquid interface was used to measure the chemical absorption rate of diluted nitrogen dioxide into sodium sulfide solution. The absorption rates under various experimental conditions were measured and the effects of experimental conditions on nitrogen dioxide absorption rate were discussed. The results show that, in the range of this study, nitrogen dioxide absorption rate increases with increasing sodium sulfide concentration, nitrogen dioxide inlet concentration, and flue gas flow rate, but decreases with increasing reaction temperature and oxygen content in flue gas.     

Evaluation of the performance of surface treatments on concrete durability

This paper reports on a laboratory-based study carried out to evaluate the effectiveness of surface treatments on the durability of concrete and suggests a number of different evaluation methodologies for assessing the performance of various surface treatments. Durability of untreated and treated concrete specimens was evaluated by measuring chloride diffusion, charge passing capacity, air permeability and water absorption. A total of six concrete surface treatments were selected to represent different generic types, including coating, penetrant and mixed-use treatments. Results show that the concrete specimens with a coating procedure have a better long-term performance and effectiveness than the specimens with the penetrant treatments. This work also indicates that the wetting and drying cycles test can be used to assess the weatherability of the surface treatments. The ASTM C 1202 and the Autoclam air permeability test can be used to evaluate the effectiveness of surface treatments quantitatively. Further work is needed, however, to assess the longevity of the various surface treatments.     

Absorption of NO2 into Na2S solution in a stirred tank reactor

To understand the absorption mechanism of nitrogen dioxide into a sodium sulfide solution, a stirred tank reactor with a plane gas-liquid interface was used to measure the chemical absorption rate of diluted nitrogen dioxide into sodium sulfide solution. The absorption rates under various experimental conditions were measured and the effects of experimental conditions on nitrogen dioxide absorption rate were discussed. The results show that, in the range of this study, nitrogen dioxide absorption rate increases with increasing sodium sulfide concentration, nitrogen dioxide inlet concentration, and flue gas flow rate, but decreases with increasing reaction temperature and oxygen content in flue gas.     

硝基苯生产中高浓度NO_X尾气的处理方法研究

针对硝基苯废酸提浓尾气处理装置存在的问题,结合废酸提浓尾气处理装置改造实例,分别采用水、未提浓混酸和氢氧化钠溶液、水和双氧水串级做吸收剂。结果表明：采用压缩法脱除有机物气体和加压法水吸收、双氧水两级串联吸收氮氧化物气体的方法,对于尾气中浓度为130000～190000mg／m^3的苯、17～38mg／m^3的硝基苯和30～90×10^4mg／m^3的氮氧化物的平均脱除率可达99％以上。     

pH-Responsive and Buffering Macromolecule Aqueous Absorbent and Mathematic Model-Based Feasibility Evaluation for SO2 Capture

An organic macromolecule, poly(1-vinylimidazole), with an appropriate polymerization degree was proposed and mixed with water to form a novel aqueous absorbent for SO_2 capture. This aqueous solution absorbent has the advantages of simple preparation, good physicochemical properties, environment-friendliness, high ability in deep removal of SO_2, and excellent reusability. Moreover, pH-responsive behavior, pH buffering absorption mechanism, and their synergistic effect on absorption performance were revealed. The solubilities of SO_2 in the absorbent were measured in detail, and the results demonstrated excellent absorption capacity and recyclability. Then, mathematic models that describe SO_2 absorption equilibrium were established, and the corresponding parameters were estimated. More importantly, on the basis of model and experimental data, the absorption and desorption could maintain high efficiency within a wide operating region. In summary, this work provided a low-cost, efficient, and unique absorbent for SO_2 capture and verified its technical feasibility in industrial application.     

笋壳基活性炭对铜离子和亚甲基蓝的共吸附性能研究

以笋壳为原材料,经过NaOH活化、碳化后制得笋壳基活性炭,研究了其对重金属及有机污染物的单独和共吸附性能。选取Cu(Ⅱ)和亚甲基蓝（MB）作为复合污染水体的特征污染物,探讨活性炭对两者的单独和共吸附性能,并从动力学角度探讨了吸附机理。结果表明,不同类型的污染物单独存在时,笋壳基活性炭对Cu(Ⅱ)和MB的吸附量分别是6.55 mg/g和 18.26 mg/g;而当上述两种污染物共存时,吸附量均明显下降,这说明Cu(Ⅱ)和MB存在竞争吸附。准二级动力学方程很好地描述了笋壳基活性炭对Cu(Ⅱ)和MB的吸附行为。吸附速率的控制步骤是内扩散,吸附速率还受膜扩散的控制。