对MMT调合汽油应用性能的研究

ＭＭＴ是甲基环茂二烯羰基锰的英文缩写,是一种提高辛烷值的汽油添加剂。用于调和汽油,增加汽油辛烷值,从而生产９０号、９３号及高标号无铅汽油。ＭＭＴ不仅能帮助炼油厂汽油产品提高等级,而且能提高高标号汽油的产量。ＭＭＴ是炼油厂极有价值的辛烷值改进剂。     

丙烯酸树脂在医用黏合剂中的应用

讨论了丙烯酸树脂在医用黏合剂中的应用及进展。     

阳离子交换树脂在聚合物生产中的应用

本文对阳离子交换树脂在聚合物生产中的所起的作用及其工作原理进行了简要介绍。     

汽油抗爆剂 MMT 的发展与应用

介绍了汽油抗爆剂甲基环戊二烯三羰基锰 MMT 物性、反应机理,MMT 在我国的发展历史、现状和未来展望,并阐述了MMT的应用经验.     

高性能热固性树脂在氯碱行业中的应用

在多年的高性能热固性树脂应用的实践经验基础上，结合目前国内外的氯碱行业中的防腐蚀技术发展，就几种高性能热固性树脂在氯碱行业中的应用进行了介绍与总结，其中包括海特酸型特种不饱和树脂和几种乙烯基酯树脂，就不同类别树脂的性能及防腐蚀性能进行了分析与研究，重点阐述了树脂在氯碱行业中的的适用场合及应用细节。这些树脂的应用情况也可作为其它相关行业的参照。     

氯醚树脂在涂料中的应用

介绍了氯醚树脂的优点、防腐机理,国内外研究现状及其在涂料中的应用。展望了氯醚树脂的应用前景。     

醛类在超临界二氧化碳中的部分氧化

据德国Karlsyuhe研究中心CPV技术化学研究院的研究人员称，己醛生成己酸的选择性氧化反应具有工业价值。该反应过程无需添加催化剂，尤其是对以二氧化碳为反应介质的工艺开发，进行了良好的验证试验。下面简要介绍从基础研究、相平衡和反应动力学的确定、直到工艺设计的开发过程。     

Microencapsulated fragrances in melamine formaldehyde resins

The process for making melamine formaldehyde microcapsules containing fragrant oil is well-known. Recently, this technology has been used to enhance the olfactory performance on fabrics. However keeping the fragrance in the capsule during storage, improving the olfactory benefit and releasing a low amount of formaldehyde is highly challenging. To answer these challenges, Givaudan has developed its own melamine formaldehyde microcapsule, called Mechacaps, which is described in this article.     

Effect of a novel environmentally friendly additive of polyaspartic acid on the properties of urea formaldehyde resins/montmorillonite

Polyaspartic acid (PASP) is a biodegradable green material with carboxyl groups ( COOH) and amido groups ( CO NH ). In the article, a novel urea-formaldehyde (UF) resin modified by PASP and Ca-montmorillonite (Ca-Mt) was prepared by the alkaline-acid-alkaline method. The synthesized materials were characterized by X-ray diffraction, Fourier transform-infrared spectroscopy, thermal analysis (TG-DTG), and scanning electron microscopy. The effects of viscosity, curing time, and free formaldehyde were investigated. The results showed that the layered structure of Ca-Mt was exfoliated and dispersed in the bulk of UF. The thermal stability of the modified UF was much better than that of pure UF resin. The percentage of free formaldehyde was declined from 26 to 18%. Meanwhile, the UF composites showed the short curing time and the optimum viscosity. Finally, a synthetic process of UF modified by PASP and Ca-Mt and a possible mechanism for immobilizing the free formaldehyde were suggested. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48038.     

Multifunctional formaldehyde resins as curing agent for epoxy resins

Formaldehyde resins (FR) at 1/1/2 molar ratios of monomers (Cl‐phenol/amino monomers/p‐formaldehyde) were synthesized under acid catalysis. The obtained resins were characterized using elemental analysis, FTIR and RMN spectroscopic methods, being used as crosslinking agents for epoxy resin formulations. The curing of epoxy resins with FR were investigated. The glass transition temperature (T_g) and decomposition behavior of crosslinked resins were studied by differential scanning calorimetry (DSC) and thermogravimetric (TGA) techniques. All DSC scans show two exothermic peaks, which implied the occurrence of cure reactions between epoxy ring and amine or carboxylic protons, in function of chemical structures of FR. The crosslinked products showed good thermal properties, high glass transitions, and low water absorption. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

13C-NMR analysis of formaldehyde resins

¹³C-NMR spectroscopy has been applied to the analysis of formaldehyde containing resins. Samples have been prepared from phenols, urea and melamine with formaldehyde. The chemical shifts of the carbon atoms in the resins were measured relative to TMS. All the samples could be dissolved in DMSO-d₆ which facilitated the comparison of signals in different resins. The spectra were interpreted with the aid of spectra of reference compounds and simple calculations based on additivity increments. Each type of resin gives a specific ¹³C-NMR spectrum in which lines can be assigned that give information on the structure of the resin in relation to the type of condensation or catalyst used. Moreover, the different ways in which formaldehyde is incorporated in the resins as methylene carbon can be unambiguously determined from the region between 20 and 100 ppm. This work shows that ¹³C-NMR spectroscopy is a powerful tool for the analysis of formaldehyde containing resins.     

脲醛树脂粘合剂中低甲醛释放的研究进展

本文概述了脲醛树脂(UF)粘 合剂的合成原理及树脂在应 用过程中释放甲醛的来源和 控制释放的方法,并论述了开 发低甲醛释放粘合剂的意义 和必要性。     

磺化三聚氰胺脲醛树脂合成工艺的研究

研究了引入尿素含量较高的条件下 ,磺化三聚氰胺脲醛树脂 (SMUF)的合成工艺影响因素及作为混凝土超塑化剂的应用性能。结果表明SMUF的优化合成条件为 :n(甲醛 )∶n(硫酸 )∶n(三聚氰胺 )∶n(尿素 ) =6∶2∶1∶1 ,羟甲基化、磺化、酸段缩合、碱性重整 4个阶段的反应温度均为 80℃ ,酸段缩聚反应阶段pH为 4 .5 ,时间为 90min。合成的SMUF树脂在用量 0 5 %时 ,混凝土的减水率可达 2 0 %。该工艺与SMF树脂合成相比 ,原料成本降低 35 %。     

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.     

Modification of acetophenone–formaldehyde and cyclohexanone–formaldehyde resins

Cyclohexanone–formaldehyde and acetophenone–formaldehyde resin were in situ modified with phenol, Bisphenols, and substituted acetophenones. Furthermore, acetophenone–formaldehyde, cyclohexanon–formaldehyde, and in situ-modified resins were modified with anhydrides such as acetic anhydride, maleic anhydride, dodecenylsuccinic anhydride, 3,4,3′,4′-biphenyltetracarboxylic dianhydride, and 4,4′-oxydiphtalic anhydride. Modification of these resins with hydroxyl amine, semicarbazide, and phenyl hydrazine were also studied. Melting points, solubilities in organic solvents, FTIR, and NMR spectrum of the modified resins were determined. © 1996 John Wiley & Sons, Inc.     

Pyrolysis of melamine–formaldehyde and urea–formaldehyde resins

Pyrolysis of melamine–formaldehyde and urea–formaldehyde resins in helium and air was investigated by means of TG and gravimetry with isothermal heating, as well as elemental and HCN analyses. Weight loss curves suggest three kinds of reactions involved in the pyrolysis, namely, initiation reactions, reactions splitting off volatile fragments, and reactions forming stabilized structures. In TG, in both helium and air atmospheres, the active weight loss of the melamine resin was completed in two steps, and that of the urea resin was completed in one step, which, however, consisted of a few small successive steps. The isothermal heating weight losses progressed through a few stages of first- and zeroth-order reactions. Arrhenius parameters were obtained for the weight losses in TG and with isothermal heating. The residue from the melamine resin is rich in carbon and nitrogen, and poor in oxygen and hydrogen, while that from the urea resin is rich in carbon, and poor in nitrogen, oxygen, and hydrogen. The effects of temperature on HCN yield changed, depending on the amount of air fed. The melamine resin evolved much more HCN than the urea resin because of the more stable C—N linkages in the resin.