高效液相色谱法测定日化用品中甲醛的含量

建立了柱前衍生、高效液相色谱法测定表面活性剂及其制品中甲醛含量的方法。乙酰丙酮作为衍生剂,铵存在的条件下与甲醛发生反应,衍生物直接进行液相分析,乙腈/水(体积比55∶45)为流动相,流速1 mL/min。Agilent ZORBAX SB-C8(4.6 mm×250 mm,5μm)为分离柱,在410 nm波长下进行检测。方法检出限0.002 mg/L,相对标准偏差0.73%~2.86%,回收率为97.9%~103.6%。该方法利用柱前衍生,生成稳定的黄色络合物,不需要进行萃取,操作简便、快速、准确性好。     

杉木液化产物用于胶粘剂制备的研究

研究用少量的苯酚液化木材及其产物用于胶粘剂制备的方法,在硫酸催化剂作用下,用苯酚液化杉木木粉,得到木材液化产物.在液化产物中加入适量的甲醛和氢氧化钠溶液制备热固性酚醛树脂.压板测试结果表明,由木材液化产物所得树脂的干状胶合强度令人满意,但经蒸汽循环试验后,湿状胶合强度尚达不到JAS标准的要求,在下阶段工作中,需进一步研究木材液化产物胶粘剂的改性以提高其胶合耐久性.     

Preparation of a mesoporous carbon membrane from resorcinol and formaldehyde

A mesoporous carbon membrane was prepared by the organic sol-gel process, ambient drying and carbonization. Resorcinol was polymerized with formaldehyde and formed a sol. The sol was cast on a porous fly-ash ceramic support by dip-coating. After ambient drying and carbonization, a carbon membrane was obtained. The carbon membrane exhibited a sharp pore size distribution with average diameter of 3 nm.     

Preparation and adsorption properties of chelating resins from thiosemicarbazide and formaldehyde

A novel chelating resin was synthesized in just one step under mild synthetic conditions. The synthesis was carried out through the copolymerization of thiosemicarbazide and formaldehyde in an aqueous solution. The adsorption properties for some noble metal ions were investigated. The results showed that the resin had high adsorption selectivity for Au(III) and Ag(I). The adsorption capacities for the two metal ions reached up to 7.3 and 11.8 mmol/g, respectively. The adsorption rate for the two metal ions in a dilute solution was 99.9%. The adsorption fit first‐order kinetics, and an isothermal adsorption study indicated that it corresponded to Langmuir monomolecular layer adsorption. The change in the bonding energy during the chelating process was investigated with X‐ray photoelectron spectroscopy. The study revealed that nitrogen and sulfur atoms of the resins were electron donors and metal ions were electron acceptors in the process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Non-ionic detergents from wax

Conclusion Non-ionic synthetic detergents having detergent properties similar to those of alkyl phenol polyethylene glycol ethers and alkyl mercapto polyethylene glycol ethers can be prepared by reacting the optimum quantity of ethylene oxide with the composite crude fatty acids made by the air oxidation of low melting chemical grade paraffin wax.     

以白乳胶为基质甲醛吸附剂的研制与应用

以白乳胶为吸收基质,选择了如氨基乙酸、干酪素、鞣质、L-谷氨酸、DL-α氨基丙酸、尿素、六次甲基四胺、木质素、分子筛作为甲醛吸附剂,涂布于聚氯乙烯胶片上做甲醛吸收测试;根据测试结果,制作的甲醛吸附剂能起到较好的甲醛吸收效果。并探讨了白乳胶中吸收剂用量的筛选及吸收时间对甲醛消除的影响因素。     

Preparation of carbon dioxide adsorbents from the chemical activation of urea–formaldehyde and melamine–formaldehyde resins

Adsorption is considered to be one of the more promising technologies for the capture of CO₂ from flue gases. In general, nitrogen enrichment is reported to be effective in enhancing the specific adsorbent–adsorbate interaction for CO₂. Nitrogen enriched carbons were produced from urea–formaldehyde and melamine–formaldehyde resins polymerised in the presence of K₂CO₃ as a chemical activation agent, with activation undertaken over a range of temperatures. CO₂ adsorption capacity was determined to be dependent upon both textural properties and more importantly nitrogen functionality. Adsorbents capable of capturing above 8 wt.% CO₂ at 25 °C were produced from the chemical activation of urea–formaldehyde resin at 500 °C. Chemical activation seems to produce more effective adsorbents than CO₂ activation.     

Preparation of cured urea–formaldehyde resins of low formaldehyde emission

Several polymers containing amino or amido groups and biuret were tested as additives to ureaformaldehyde (UF) resin in order to neutralize its inherent acidity and combine free formaldehyde released upon hydrolysis of cured UF polycondensate. Each modifier was incorporated to liquid methylolureas at weight ratios of 1:100, 2:100, and 3:100 prior to curing with the aid of acetic acid. Over 10 days of maintaining aqueous suspensions of the ground-up resultant solid resins at ambient temperature, a neutralizing effect was exhibited most visibly by polyacrylamide, polymethacrylamide, and biuret, the test with chitosan and casein giving results slightly different from those obtained for the control nonmodified cured UF polymer. Polyacrylamide, biuret, and casein proved to be excellent inhibitors of formaldehyde release from the hardened resins which were suspended in water at ambient temperature. On the other hand, chitosan did not reduce the evolution of HCHO but, instead, augmented it when its content was 1 g/100 g of the original liquid resin before cure.     

Some synthetic detergents from petroleum products

Deodorized and dewaxed Egyptian petroleum fraction, boiling range 200–270 C, was subjected to liquid phase oxidation at various temperatures in the presence of Co acetate as catalyst. The synthesized naphthenic acids were then converted to naphthenic acid amides and naphthenic alcohols. These products were ethoxylated to different mole ratios of ethylene oxide. The ethoxylates with an average 5 mol ethylene oxide/mol prepared hydrophobes were sulphated and phosphated to anionics. The surface active properties of all the nonionic and anionic surfactants were evaluated.     

Formose sugars from formaldehyde

A mixture of sugars is produced by base catalysed condensation of formaldehyde. The sugars range from four to seven carbon atoms, mainly six. They are sufficiently toxic to kill rats at 50% of the diet level, possibly due to the multiplicity of species as well as the presence of branched sugars. Manipulation of the reaction conditions can effect a 75% selectivity to racemic glucose, but its economic recovery is improbable. The formose sugars were tested for cancer tumor growth suppression activity, but none was found.     

邻甲酚醛环氧/改性凹凸棒土复合材料的制备

采用硅烷偶联剂KH560对提纯后的凹凸棒土(AT)进行改性,得到有机化凹凸棒土,并对其进行FTIR和TG表征,结果表明,KH560对凹凸棒土起到了良好的修饰改性作用。采用熔融复合法制备了AT质量分数为0～5%的邻甲酚醛环氧/凹凸棒土纳米复合材料(ECN/(KH560-AT)x),对其进行了扫描电镜(SEM)分析、动态力学分析(DMA)和热重分析以及力学性能测试。结果表明,KH560-AT的加入使复合材料断裂由脆性断裂向韧性断裂转变。ECN/KH560-AT复合材料的拉伸强度、冲击强度和Tg可比纯ECN分别高出54.12%、78.95%和37.5℃,KH560-AT的加入明显提高了复合材料的力学性能和耐热性。     

对叔丁基酚胺醛树脂型破乳剂的制备

选取对叔丁基苯酚、甲醛、二乙烯三胺为原料合成对叔丁基酚胺醛树脂作为起始剂,KOH为催化剂,通过与环氧乙烷(EO)、环氧丙烷(PO)加成反应合成对叔丁基酚胺醛树脂型嵌段聚醚破乳剂。性能优良破乳剂的关键为起始剂的制备,本实验通过单因素法确定合成的工艺条件为:对叔丁基苯酚∶甲醛∶二乙烯三胺=1∶0.8∶0.8(摩尔比),反应温度为95℃,反应时间为180 min。利用红外光谱、核磁共振氢谱对起始剂的结构进行表征。结果表明,起始剂为目标产物。对叔丁基酚胺醛树脂型破乳剂对辽河老化油脱水实验结果表明,破乳剂脱水速率快,脱水率较高,且油水界面清晰整齐,能够达到老化油工业化处理的应用条件。     

日用级三聚氰胺甲醛模塑料的制备

以三聚氰胺甲醛树脂为胶粘剂,纤维素为增强材料,制得三聚氰胺甲醛模塑料。通过测试模塑料的力学性能、流动性、挥发分及模收缩率和吸水率等,研究了三聚氰胺与甲醛配比、反应终点控制、纤维素含量、干燥温度、模塑粉细度等对模塑料性能的影响。结果表明,三聚氰胺与甲醛物质的量比为1∶2.5、终点控制在水浊度1∶3,纤维素用量42%~48%,干燥温度70℃,球磨至100~120目时,制得的模塑料性能良好,符合国家日用级产品相关标准。     

Preparation of sec-butanol-modified melamine–formaldehyde resin varnish

sec-Butanol was employed to prepare etherified methylol–melamine resins to be used in the coatings industry as crosslinking agents. Difficulties associated with slow rate of etherification as compared to the rate of polycondensation of methylol–melamine were overcome by finding the determining factors which controlled the two competitive reactions independently. Attempts were made to interpret the effects of various factors from a mechanistic point of view.     

密胺树脂微球微胶囊的制备及应用研究进展

概述了密胺树脂(MF)微球微胶囊的研究近况,重点介绍了密胺树脂微球微胶囊的制备与改性方法、应用领域.总结了目前存在的主要问题,对未来的发展方向进行展望.     

对叔丁基酚胺醛树脂型破乳剂的制备

选取对叔丁基苯酚、甲醛、二乙烯三胺为原料合成对叔丁基酚胺醛树脂作为起始剂,KOH为催化剂,通过与环氧乙烷(EO)、环氧丙烷(PO)加成反应合成对叔丁基酚胺醛树脂型嵌段聚醚破乳剂。性能优良破乳剂的关键为起始剂的制备,本实验通过单因素法确定合成的工艺条件为:对叔丁基苯酚∶甲醛∶二乙烯三胺=1∶0.8∶0.8(摩尔比),反应温度为95℃,反应时间为180 min。利用红外光谱、核磁共振氢谱对起始剂的结构进行表征。结果表明,起始剂为目标产物。对叔丁基酚胺醛树脂型破乳剂对辽河老化油脱水实验结果表明,破乳剂脱水速率快,脱水率较高,且油水界面清晰整齐,能够达到老化油工业化处理的应用条件。     

低游离甲醛含量酚醛树脂胶粘剂的合成

采用两次加碱一次回流法合成工艺代替一次法和两次碱法制备了酚醛树脂胶粘剂。对产物粘度,游离甲醛含量及固化物拉伸剪切强度测试,研究了酚醛比、催化剂加入量、反应温度、回流时间等对产物性能的影响。结果表明:苯酚与甲醛物质的量比1∶2,催化剂加入量为苯酚质量分数的25%,回流反应45 min可得到具有交联结构的酚醛树脂胶粘剂,产品分子质量及粘度适中,拉伸剪切强度可达到5 MPa以上,游离甲醛质量分数<0.03%,稳定性较好。     

New nonionic detergents derived from epoxidized oils

A new class of nonionic detergents derived from epoxidized oils having an oxirane oxygen content of 6–10% is discussed. Their mol wt and micellar wt distributions, as studied in the ultracentrifuge, are presented and cited as partial explanations for their unique properties as compared to conventional nonionic detergents such as ethoxylated alkyl phenols. Critical micelle concentrations (CMC) determined by light scattering data are presented.     

Methods for removing detergents from waste waters

A number of processes have been investigated or are being investigated for removal of alkyl-benzene sulfonate (ABS) from waste waters. These can be divided into processes applicable to launderette wastes and processes applicable to municipal waste water although there is overlap. Launderette waste treating methods include, flocculation, flotation, adsorption on activated carbon or ion exchange materials and filtration. In municipal waste water treatment any ABS removal method must be very inexpensive. Two methods that have been used to remove most of the residual ABS after conventional sewage treatment are foaming and adding of cationic detergents. Both methods are capable of removing ABS down to levels of 0.5 ppm or less. A number of other treatment methods that will remove organics, including ABS, from municipal wastes are being studied. Their costs are, in general, too high to make them applicable for ABS removal alone. Processes under study include adsorption, chemical oxidation, ion exchange, electrochemical degradation and even distillation.