N-异丙基丙烯酰胺与N-异丙基甲基丙烯酰胺的酸催化合成改进

用Ｎ 异丙基丙烯酰胺（ＮＩＰＡＭ）与Ｎ 异丙基甲基丙烯酰胺（ＮＩＰＭＡＭ）单体可合成温度敏感型高分子材料。作为单体的合成方法,首先把浓硫酸与异丙醇混合,而后加入丙烯腈（或甲基丙烯腈）,经催化反应后,反应液用乙醚萃取、正己烷重结晶,可得相应的氮取代丙烯酰胺。报告了在常温、常压下,在浓硫酸催化下,丙烯腈与异丙醇的摩尔比为１∶１时,Ｎ 异丙基丙烯酰胺与Ｎ 异丙基甲基丙烯酰胺的产率为６０％～７０％。分别测定了它们的红外光谱与核磁共振谱,发现与对应样品的标准图谱基本一致。通过改变萃取剂,用乙醚替代一般方法使用的二甲苯,可使萃取物易于从萃取剂中分离出来。乙醚可重复使用,每个操作周期乙醚损失约１０％。     

甲基磺酰胺合成工艺研究

以甲基磺酰氯为原料，通过氨解反应合成了甲基磺酰胺，探讨了合成反应的工艺条件。实验表明，当原料用量与溶剂的体积比为1：5时，反应温度控制在35－40℃之间，用环己烷作为反应的溶剂，并以乙醇作萃取分离剂，可使产品的收率达87％－89％。     

间歇萃取精馏分离苯-环己烷

利用间歇萃取精馏分离技术,分别以N,N-二甲酰胺(DMF)、二甲基亚砜(DMSO)和二者的混合物作为萃取剂,对苯、环己烷近沸点体系的分离进行了试验研究,考察了操作参数回流比和溶剂流率对分离效果的影响,结果表明:随着回流比和溶剂流率的增加,分离效果增强;三种萃取剂均能对苯和环己烷进行有效的分离,但分离效果不同,其中以DMF∶DMSO=3∶1(质量比)混合物作为萃取剂时效果最好,其次是DMF。试验结果得到的最佳分离条件是:萃取剂为DMF∶DMSO=3∶1混合物,溶剂流率为12.33 mL/min,回流比为4,其产品中环己烷摩尔分数可达86.98%以上,环己烷收率可达83.10%。     

汉源花椒挥发油超临界CO_2萃取与GC-MS分析

用超临界CO2萃取汉源花椒挥发油,并以GC-MS分析了其成分。通过正交实验确定超临界CO2萃取挥发油的优化条件为:以75%乙醇(添加量为原料质量的5%)为夹带剂、萃取压力30 MPa、萃取温度40℃、萃取时间2.0 h,此时,挥发油的收率为9.92%。用GC-MS分离出69个峰,鉴定出56种物质,主要成分为:芳樟丁酸酯(30.212%)、(1α,3α,4β,6α)-4,7,7-三甲基-双环[4.1.0]庚烷-3-醇(10.940%)、(+)-4-蒈烯(1.826%)、4-亚甲基-1-(1-甲基乙基)-双环[3.1.0]环己烷(1.109%)、β-月桂烯(1.170%)、柠檬烯(5.784%)、3,7-二甲基-1,6-辛二烯-3-醇(5.742%)、n-棕榈酸(0.914%)、(Z,Z)-9,12-十八碳烯酸(2.952%)等。结果表明,汉源花椒挥发油的超临界CO2萃取收率比水蒸气蒸馏的收率高,且成分丰富。     

复配成孔剂对高吸水树脂吸液性能的影响

以丙烯酰胺(AM)、丙烯酸(AA)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)为单体,过硫酸铵为引发剂,N,N-亚甲基双丙烯酰胺为交联剂,山梨醇酐单硬脂酸酯为分散剂,碳酸氢钠与丙酮为复配成孔剂,采用反相悬浮聚合法制备了AA/AM/AMPS多孔型高吸水树脂,并研究了成孔剂种类、复配成孔剂配比、水与环己烷质量比(简称水油比)、中和度、交联剂用量对高吸水树脂吸液性能的影响。结果表明:在水油比为1.0∶2.5,中和度为73%,交联剂用量为0.3%(w),碳酸氢钠与丙酮质量比为1.0∶1.5时,高吸水树脂的吸水倍率和吸盐倍率达到最高,分别为1732.5,142.9 g/g,且具有较好的保水性能。     

正己烷+苯甲醇,甲基环己烷+苯甲醇及甲基环戊烷+苯甲醇体系汽液平衡数据的测定与关联

使用Ellis汽液平衡釜测定常压下正己烷+苯甲醇,甲基环己烷+苯甲醇和甲基环戊烷+苯甲醇体系的汽液平衡数据,并对实验数据进行了热力学一致性检验,结果表明数据通过检验;此外,利用Wilson方程对实验数据进行关联,关联结果与实验数据吻合较好。基于关联的二元交互作用参数,本文借助流程模拟软件Aspen Plus,以苯甲醇为萃取剂,对正己烷+甲基环己烷和正己烷+甲基环戊烷两个体系进行萃取精馏模拟计算。结果表明,苯甲醇可作为正己烷+甲基环己烷分离的萃取剂,但不适于作为萃取剂分离正己烷+甲基环戊烷共沸体系。     

用超临界二氧化碳法制备超强吸水剂

以N，N’-亚甲基双丙烯酰胺(BIS)为交联剂，研究了疏水性单体丙烯酸十八酯(OA)与亲水性单体丙烯酸(AA)在超临界二氧化碳中的聚合反应，制备了超强吸水剂。结果表明，65℃、压力大于13MPa时，制备的产物都为白色固体粉末。用超临界二氧化碳萃取技术可以对产物进行纯化，50℃、20MPa下，产物经超临界二氧化碳萃取2次后纯度可大于95％，4次后单体残留率为0．28％。该超强吸水剂的吸水率有一定下降，然而保水率却得到提高。     

反相悬浮聚合法合成高吸水性树脂的研究

以环己烷为分散介质,聚乙烯醇为主分散剂,十二烷基磺酸钠为助分解剂,Ｎ,Ｎ－亚甲基双丙烯酰胺为交联剂,过硫酸钾为引发剂,采用反相悬浮聚合法合成了丙烯酸－丙烯酸－丙烯酰胺三元共聚交联型高吸水性树脂,产物呈软珠粒状。吸自来水达６５０倍,０．９％的生理盐水达７５倍。     

1,1,1-三羟甲基丙烷三硝酸酯的合成与表征

以三羟甲基丙烷为原料,通过硝化反应,合成了1,1,1-三羟甲基丙烷三硝酸酯,研究了不同硝化剂对合成1,1,1-三羟甲基丙烷三硝酸酯的影响,找出了最佳添加剂和硝化剂。实验结果表明,当用98％硝酸作为硝化剂,三羟甲基丙烷与硝酸摩尔比为10：1,反应温度在0～20℃,反应时间为2h,1,1,1-三羟甲基丙烷三硝酸酯的收率可达99．7％,并用红外光谱、核磁共振、元素分析等对产品进行了表征。     

微乳液中环己烷和十六烷基三甲基溴化铵的回收

用破乳、蒸馏、萃取的方法回收组成为环己烷／十六烷基三甲基溴化铵／盐水／正丁醇的微乳液中的环己烷和十六烷基三甲基溴化铵，通过正交实验确定最佳破乳条件，结果表明：环己烷收率93．9％，十六烷基三甲基溴化铵收率38．3％。     

低色度聚乙二醇(200)双甲基丙烯酸酯的合成

以聚乙二醇(PEG-200)和甲基丙烯酸甲酯(MMA)为原料,采用酯交换法合成聚乙二醇(200)双甲基丙烯酸酯大分子功能单体。考察了溶剂、催化剂、阻聚剂和脱色剂对酯交换反应的影响。结果表明,在酯交换反应中,溶剂环己烷能够降低反应温度,且易于脱出副产物甲醇。当m(环己烷)∶m(总反应液)=2∶5,m(碳酸钾)∶m(醇酯总质量)=8.5∶100,m(氢醌单甲醚)∶m(醇酯总质量)=1.1∶100和m(脱色剂A)∶m(醇酯总质量)=2.1∶100时,产率可达到80.2%,色度为50 APHA。     

A method for the calculation of compositions of radical-chain copolymerizations

In this article the straight-line relationship between In A and B, where A and B denote the concentrations of the two types of monomers in any reaction period, is examined to exist in the radical copolymerizations of 1.02 ≥ r₁r₂ ≥ 0.25. Utilizing this observation, we propose an easy-to-use compositions calculation method in which a single empirical parameter is included. The method is derived without involving the constant monomer reactivity ratios assumption. The copolymerizations of styrene–methyl methacrylate vinyl chloride–vinyl acetate, methyl methacrylate–vinyl acetate, acrylic acid–acrylamide, methacrylic acid–methacrylamide, and sodium methacrylate–methacrylamide are investigated. The instantaneous and cumulative copolymer compositions and the residued monomer compositions computed by this proposal are in very good agreement with the experimental data.     

Effect of solvent on anthraquinone-sensitized photopolymerization of methyl methacrylate

Photopolymerization of methyl methacrylate was carried out in the system containing anthraquinone (AQ) sensitizer and solvent under nitrogen at 30°C. Hydrocarbons, alcohols, and mixtures of both, for example, cyclohexane and isopropanol, were used as solvents. The maimum yield of polymerization was observed at a certain concentration of alcohol in hydrocarbon, a phenomenon which is discussed from measurements of polymer molecular weight and the UV spectrum of irradiated AQ.     

Characteristics of permeation and separation of dimethyl acrylamide-methyl methacrylate random and graft copolymer membranes for a benzene/cyclohexane mixture

When a benzene/cyclohexane mixture was permeated through poly(dimethyl acrylamide-random-methyl methacrylate) (DMAA-r-MMA) and poly(dimethyl acrylamide)-graft-poly(methyl methacrylate) (DMAA-g-MMA) membranes by pervaporation, the benzene-permselectivity of the DMAA-r-MMA membrane changed from the diffusivity selectivity to the solubility selectivity with increasing DMAA content but DMAA-g-MMA membranes with a high DMAA content had the higher apparent diffusivity selectivity than the apparent solubility selectivity. Furthermore, the apparent solubility selectivity for a benzene/cyclohexane mixture between the DMAA-r-MMA membrane and the DMAA-g-MMA membrane with a high DMAA content was remarkably different. These results were attributed to the difference of structure between the copolymers. Received: 27 August 1997/Revised version: 22 October 1997/Accepted: 30 October 1997     

3-氨基-2-噻吩甲酸甲酯的合成工艺

文章研究了以甲醇钠为催化剂,巯基乙酸甲酯、2-氯丙烯腈为原料合成3-氨基-2-噻吩甲酸甲酯的工艺。考察了原料配比、反应温度、反应时间以及萃取剂对反应收率的影响,结果显示当2-氯丙烯腈、巯基乙酸甲酯和甲醇钠三者的摩尔比为1∶1.2∶3.3时,体系在25～30℃反应4 h,以三氯甲烷为萃取剂时,收率可达到88.2%。     

Extraction and recovery of cadmium(Ⅱ) using phosphine-oxide,tris[(dibutylamino)methyl]-(7CI,8CI) from nitric acid solutions

In the present article, a new separation system was employed for the extraction of cadmium from nitric acid solutions for the first time. Phosphine oxide, tris[(dibutylamino)methyl]-(7CI,8CI),which contains nitrogen atoms and phosphorus atom in molecular, was used as extractant. The influence of the following parameters was investigated: the organic/aqueous phase ratio (O/A), pH, contact time, temperature, the concentration of extractant, cadmium (Ⅱ), sodium nitrate and sodium chloride. Results demonstrated that quantitative extraction of cadmium was feasible from 50 mg/L cadmium feed solution in a single stage at pH 3.0, 15 min and O/A phase ratio 1:5 with 20% extractant in cyclohexane diluent. The cadmium extraction isotherm under different cadmium ion concentrations was established. The loaded cadmium could be stripped by 4 mol/L ammonium chloride aqueous solutions. A contrast study was carried out, and the results indicated that phosphine oxide, tris[(dibutylamino)methyl] –(7CI,8CI), could take the place of commercial organo-phosphorous extractants in the process of cadmium(II) extractions for its effectivity, stability and low price.     

Transition phenomena of polymers in mixed solvents in the vicinity of theta conditions: Effect of preferential adsorption

Viscosimetric measurements were obtained with the ternary systems polystyrene/dioxane/methanol, polystyrene/benzene/methanol and poly(methyl methacrylate)/dioxane/cyclohexane, changing the solvent mixture composition at constant temperature. The polystyrene and poly(methyl methacrylate) systems exhibit a transition phenomenon with solvent-mixture composition in which the polymer is just above the theta condition. In the case where two theta conditions occur ((θ-intra, θ-inter) the transition point is closely related to the intramolecular theta conditions. Moreover the intramolecular theta conditions vary with the molecular weight in the region of molecular weights where the preferential adsorption also varies. This variation induces a variation of the transition point with molecular weight which obeys a formula analogous to that giving the variation of the preferential adsorption with molecular weight.     

Compatibilization of poly(methyl acrylate) with poly(methyl methacrylate) through charge transfer interactions

Summary Copolymers of methyl acrylate (MA) with an electron-donor comonomer (N-vinylcarbazole) (NVC) are mixed with copolymers of methyl methacrylate (MMA) with a electron-acceptor comonomer (2-(3,5-dinitrobenzoyl) oxyethyl methacrylate) (DNBM) such that 1:1 mol ratios of NVC:DNBM are present at all times. The blends obtained are phase separated up to an average of 27 mol% donor/acceptor structural unit in the copolymer. Above 27 mol% perturbation, poly(MA) and poly(MMA) become compatible.     

加盐萃取精馏分离苯-环己烷

测定不同萃取剂和盐对苯-环己烷共沸物相对挥发度的影响,研究不同质量分数的盐和萃取剂与原料液体积比对苯-环己烷体系相对挥发度的影响以及萃取剂加入速率和回流比对加盐萃取精馏的影响,按实验确定的最佳工艺条件进行重复实验。结果表明:采用N,N-二甲基甲酰胺(DMF)作为萃取剂,加入质量分数为15%的KAc,萃取剂与原料液体积比为0.75,萃取剂加入速率为6 mL/min,回流比为3,可得到纯度大于98%的环己烷。与常规萃取精馏相比,加盐萃取精馏所需萃取剂与原料液体积比小,所得环己烷的纯度较高。塔底釜液经减压精馏,可得质量分数大于99.5%的苯和苯质量分数小于0.15%的加盐萃取剂。     

Anionic polymerization of p-(2,2′-diphenylethyl)styrene and applications to graft copolymers

Well-controlled anionic polymerization of an initiator-functionalized monomer, p-(2,2′-diphenylethyl)styrene (DPES), was achieved for the first time. The polymerization was performed in a mixed solvent of cyclohexane and tetrahydrofuran (THF) at 40 °C with n-BuLi as initiator. When the volume ratio of cyclohexane to THF was 20, the anionic polymerization of DPES showed living polymerization characteristics, and well-defined block copolymer PDPES-b-PS was successfully synthesized. Furthermore, radical polymerization of methyl methacrylate in the presence of PDPES effectively afforded a graft copolymer composed of a polystyrene backbone and poly(methyl methacrylate) branches. The designation of analogous monomers and polymers was of great significance to synthesize a variety of sophisticated copolymer and functionalize polymer materials.