半碳化离子交换纤维的研究

本文对半碳化离子交换纤维(SCSIEF)的制备条件、反应机理和产物结构以及对金属离子的交换吸附行为进行了研究。将天然纤维经半碳化处理后,分别用浓 H_2SO_4、浓 HNO_3、HSO_3Cl 氧化或磺化处理,可制得具有较高交换容量的 SCSIEF。实验结果表明:SCSIEF 的最高交换容量可达9.16meq/g,最佳制备条件为半碳化温度300—400℃,磺化温度90—100℃,反应时间90min。这种 SCSIEF 对稀土金属离子 La~(3+1)过渡金属离子 Cu~(2+)、Co~(2+)、Ni~(2+)、Hg~(2+)、Cd~(2+)有较好的交换吸附性能。特别对贵重金属离子 Ag~+、Au~(3+)有优异的交换吸附能力。     

聚丙烯离子交换纤维研究

利用超声波分散原理将苯乙烯（St）分散到聚丙烯纤维（PP）中，以过氧化苯甲酰（BPO）作为引发剂，使苯乙烯接枝到PP纤维表面，得到PP－g-St纤维；然后用浓硫酸将PP－g-St纤维磺化，制成强酸型离子交换纤维。研究了反应时间、反应温度等对离子交换纤维的质量摩尔浓度的影响，并用红外光谱加以表征。结果表明：温度90℃下磺化反应2h，可得到离子交换质量摩尔浓度为0.95mmol/g的强酸型离子交换纤维。     

海岛型阳离子交换纤维的研究

阐述了海岛型阳离子交换纤维的制备方法,对交联、磺化过程中的硫酸浓度,多聚甲醛的添加量,反应时间,反应温度等对离子交换容量的影响进行了讨论。     

阴离子交换纤维的制备及吸附Cr(Ⅵ)性能研究

采用共辐射引发接枝共聚法在聚丙烯纤维上接枝苯乙烯-二乙烯苯,通过氯甲基化反应和胺化反 应制备强碱性阴离子交换纤维。当单体体积分数为20％-25％,辐射剂量率为1.2~1.8 kGy/h时,接枝率 可以控制在150%~250%。当氯甲基化反应温度(38±2)℃,反应时间15~25 h,胺化反应温度(30±2)℃, 反应时间15-20 h时,制备的强碱性阴离子交换纤维交换容量达到3.00 mmol/g以上。将该纤维对Cr(Ⅵ) 进行吸附试验,结果纤维对Cr(Ⅵ)的吸附以液膜扩散为主,吸附速度很快,8 min可达到吸附饱和,吸附反应 速率常数为0.015 s-1,静态吸附饱和容量为257.6 mg/g,吸附行为符合Freundlish等温吸附模型。     

中空聚丙烯基离子交换纤维的制备及表征

以CaCO_3为成孔剂,通过共混熔融纺丝和酸化制备中空聚丙烯纤维,以纤维为基体,通过引发剂接枝苯乙烯,再经氯甲基化和胺化反应制备强碱性阴离子交换纤维;采用红外光谱、电镜扫描、热重分析等分析手段对制备的离子交换纤维进行了表征,并对其交换容量、溶胀性及动力学吸附性能进行了测试。结果表明:制备的强碱性阴离子交换纤维具有较高的交换容量,约达到3.08 mmol/g,吸附性能良好,含水量大于56%,是一种性能优良的离子交换纤维。     

低湿条件下离子交换纤维吸附性能的研究

以超高交联聚丙烯-苯乙烯-二乙烯基苯(PP-ST-DVB)纤维为母体,分别经磺化、氯甲基化和胺化反应制得强酸或强碱离子交换纤维;研究了在低湿条件下对酸碱有害气体的动态吸附性能。结果表明:强酸离子交换纤维(交换容量为2.92 mmol/g)对NH_3气体的穿透吸附量约为40.95 mg/g,高于Fiban K-1磺酸型离子交换纤维的穿透吸附量;强碱离子交换纤维对SO_2气体的穿透吸附量约为77.50 mg/g,是Fiban A-1强碱离子交换纤维的1.55倍,自制的强酸、强碱离子交换纤维可多次再生使用。     

共辐射引发聚丙烯纤维接枝苯乙烯-二乙烯苯的中试研究

以60Co-γ射线为辐射源,引发聚丙烯纤维共辐射接枝苯乙烯–二乙烯苯,研究了反应物料达到中试生产规模时剂量率、辐射时间以及回收的母液对接枝纤维导入率的影响。结果表明,反应物料增加后,剂量率需适当降低才能保证接枝反应平稳、均匀地进行。当聚丙烯纤维质量为20 kg、单体浓度25%、剂量率0.8 kGy.h-1、辐射时间7 h时,接枝纤维导入率为280%～293%且力学性能良好。共辐射过程中使用的母液可重复利用。将接枝纤维磺化后制备的强酸性离子交换纤维交换容量可达到3.7～4.2 mmol.g-1。     

阴离子交换纤维的制备及吸附Cr（VI）性能研究

采用共辐射引发接枝共聚法在聚丙烯纤维上接枝苯乙烯-二乙烯苯,通过氯甲基化反应和胺化反 应制备强碱性阴离子交换纤维。当单体体积分数为20％-25％,辐射剂量率为1.2~1.8 kGy/h时,接枝率 可以控制在150%~250%。当氯甲基化反应温度(38±2)℃,反应时间15~25 h,胺化反应温度(30±2)℃, 反应时间15-20 h时,制备的强碱性阴离子交换纤维交换容量达到3.00 mmol/g以上。将该纤维对Cr(Ⅵ) 进行吸附试验,结果纤维对Cr(Ⅵ)的吸附以液膜扩散为主,吸附速度很快,8 min可达到吸附饱和,吸附反应 速率常数为0.015 s-1,静态吸附饱和容量为257.6 mg/g,吸附行为符合Freundlish等温吸附模型。     

亚临界二甲醚协助双单体固相接枝改性聚丙烯

以亚临界二甲醚为溶胀剂,偶氮二异丁腈(AIBN)为引发剂,在聚丙烯(PP)上接枝甲基丙烯酸缩水甘油酯(GMA)和苯乙烯(St),制备了接枝产物PP-g-(GMA-co-St)。考察了溶胀时间、溶胀温度、反应时间、反应温度、St用量和引发剂用量对接枝产物相对接枝率和水接触角的影响。采用傅里叶变换红外光谱对接枝产物进行定量分析,以表征相对接枝率的大小。结果表明:当溶胀时间3 h,溶胀温度55℃,反应时间3 h,反应温度85℃,m(PP)∶m(GMA)∶m(St)∶m(AIBN)=100.0∶10.0∶10.0∶0.6时,接枝产物PP-g-(GMA-co-St)的相对接枝率为5.86%,水接触角为67.19°。     

强酸弱碱型两性离子交换纤维的制备I.苯乙烯和4-乙烯基吡啶的接枝共聚

采用聚丙烯纤维为原料 ,研究了预辐照接枝苯乙烯 (St)和 4 -乙烯基吡啶 (4 - VP)的接枝共聚规律。选择合适的接枝工艺条件 ,总接枝率可达 30 0 %～ 70 0 %。通过改变 St和 4 - VP单体的投料比或采用分批投料方式还可以改变两种官能团的比例和系列结构。经进一步磺化 ,可制得两性离子交换纤维。     

Fatty acid monoesters of 1-ascorbic acid and d-isoascorbic acid

Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic, palmitic, and stearic acids in 40–50 per cent yields. Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified. Antioxidant properties of these esters are being studied. Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers.     

Electrosynthesis of 2,3-dimethyltartaric acid from pyruvic acid in acid medium

This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H₂SO₄) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%.     

Conjugated linoleic acid production from linoleic acid by lactic acid bacteria

After screening 14 genera of lactic acid bacteria, Lactobacillus plantarum AKU 1009a was selected as a potential strain for CLA production from linoleic acid. Washed cells of L. plantarum with high levels of CLA production were obtained by cultivation in a nutrient medium with 0.06% (wt/vol) linoleic acid (cis-9,cis-12-octadecadienoic acid). Under the optimal reaction conditions with the free form of linoleic acid as the substrate, washed cells of L. plantarum produced 40 mg CLA/mL reaction mixture (33% molar yield) from 12% (wt/vol) linoleic acid in 108 h. The resulting CLA was a mixture of two CLA isomers, cis-9,trans-11 (or trans-9,cis-11)-octadecadienoic acid (CLA1, 38% of total CLA) and trans-9,trans-11-octadecadienoic acid (CLA2, 62% of total CLA), and accounted for 50% of the total FA obtained. A higher yield (80% molar yield to linoleic acid) was attained with 2.6% (wt/vol) linoleic acid as the substrate in 96 h, resulting in CLA production of 20 mg/mL reaction mixture [consisting of CLA1 (2%) and CLA2 (98%)] and accounting for 80% of total FA obtained. Most of the CLA produced was associated with the cells (ca. 380 mg CLA/g dry cells), mainly as FFA.     

乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的联合测定

以正丁醇为内标,氢火焰离子化检测器测定,建立了气相色谱法直接进样测定乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的方法。在载气（N2）流速为30mL·min^-1,氢气流速为88mL·min^-1,空气流速为300mL·min^-1,进样器和离子室温度为160℃,柱温为150℃的10％PEG-20M（3m×3mml填充柱上能实现很好的分离。乳酸和丙烯酸测定方法的线性相关系数分别为0．9994和0．9996,相对标准偏差分别为O．74％和0．56％,平均回收率分别为97．35％-1197．60％,检出限分别为8．62mg·L^-1和1．21mg·L^-1方法简便、快速、准确。     

由氯乙酸副产盐酸精制高纯盐酸

开发研究了氯乙酸副产盐酸的精制工艺及盐酸中有机杂质的紫外分光光度分析方法。副产盐酸经酸洗、吸收、蒸馏得高纯盐酸。中试结果表明 ,工艺合理 ,精制盐酸达到GB 32 0 - 93规定的工业用合成盐酸标准     

炼厂酸性气制取硫酸生产总结

介绍炼厂酸性气制硫酸装置的工艺过程。由于实供气源与设计值有较大出入,二氧化碳浓度偏高, 并且夹带烃类物质较多,使装置无法正常运行。通过对酸性气进行预处理后,一次开车成功,各项工艺指标均达到设计要求,遇酸性气流量突降时可补充适量硫磺,维持正常生产。     

The performic acid oxidation of linoleic acid

The performic acid oxidation of linoleic acid has been shown to form 9,12-dihydroxy-trans-10,11-methylene-heptadecanoic acid (I) after hydrolysis of the formate ester. A sequence of reactions led to the identification of dimethyl-trans-1,2-cyclopropanedicarboxylate by gas liquid chromatography. Spectroscopic evidence is presented for thetrans geometry in I. Failure of the monoepoxide of linoleic acid to give the formate ester of I suggests the alternative that a homoallylic carbonium ion is formed directly upon attack of the peroxide reagent.     

液相色谱法测定氯乙酸中乙酸、二氯乙酸的含量

提出了液相色谱法测定氯乙酸中乙酸和二氯乙酸含量的分析方法,计算出氯乙酸的含量,并与现行工业氯乙酸国标分析方法进行了比较,证明液相色谱分析方法简洁、快速,分析结果准确,在氯碱行业具有推广运用的价值。     

Electrosynthesis of iminodiacetic acid from nitrilotriacetic acid

The electrosynthesis of iminodiacetic acid by electrooxidation of nitrilotriacetic acid in undivided cells has been studied using Zn, Cu, PbO₂, DSA^®O₂, DSA^®Cl₂, C, Ni and porous carbon as anodes. Results show that the synthesis is possible in both acid and basic mediums. The best results were obtained in aqueous 40% w/w sulphuric acid with porous carbon RVC-4000 as anode and SUS 316 as cathode, at 60 °C, 400 mA cm^-2 and charge 95% of theoretical. Under these conditions, nitrilotriacetic acid conversion was 92%, current efficiency 80% and selectivity 85%. Loss of selectivity was due to chemical side reaction between iminodiacetic acid and HCHO electrogenerated in the electrolysis.