Impurity Distribution Behavior in Caprolactam Extraction with Environmentally Benign Mixed Solvents

In a previous study a solvent mixture of heptane containing 40 mass % heptanol was selected as an alternative in the industrial extraction of caprolactam to replace benzene, toluene, or chlorinated hydrocarbons. This work reports the equilibrium distribution ratio of caprolactam and four model impurities of organic nature, namely, cyclohexanone, aniline, n‐methylcaprolactam, and cyclohexane‐carboxamide, comparing the mixed solvents with toluene as a reference. The resulting phase equilibria were interpreted using the equilibrium stage model. Based on these calculations it was found that, compared to toluene, the co‐extracted fraction of cyclohexanone and aniline was higher, that of n‐methylcaprolactam was comparable, and that of cyclohexane‐carboxamide was lower using the mixed solvent. Overall, the mixed solvent reduced the fraction of co‐extracted impurities by almost 10 %.     

国内外己内酰胺生产技术进展

介绍了己内酰胺的生产技术现状及其进展,分析了国内外己内酰胺的生产消费现状及发展前景,提出了发展我国己内酰胺生产的建议。     

己内酰胺复配异氰酸酯改性蒙脱土的制备与表征

以己内酰胺(CL)为插层剂,二苯基甲烷-4,4'-二异氰酸酯(MDI)为改性剂,制备己内酰胺复配异氰酸酯改性钠基蒙脱土(Na-MMT).将复配改性制得的有机蒙脱土再与Na-MMT、己内酰胺插层的Na-MMT和异氰酸酯(MDI)改性的Na-MMT进行对比研究.利用电感耦合等离子体发射光谱(ICP-OES)、能量色散偏振X射线荧光光谱仪(XRF)、红外光谱(FTIR)、热重分析(TG)和电子显微镜(TEM)对改性前后的Na-MMT进行表征.结果表明,己内酰胺能进入水溶胀的Na-MMT层间,但对层间阳离子(Na+)含量影响不大;MDI能与MMT外表面和端面吸附的水反应生产取代脲对MMT进行有机包覆,而对MMT的分散和层间阳离子含量影响不大;只有己内酰胺复配MDI改性的MMT,其层间阳离子含量显著降低,且微观上呈纳米级分散.     

锦纶己内酰胺原料液体化运储系统介绍

分析了锦纶原料—己内酰胺固态运输的缺点,介绍了其液体化运输方案及有关设备的技术特点,并分析了技改后的经济效益。     

UV-791对PA6抗紫外光老化和热氧稳定性的影响

在己内酰胺水解开环聚合过程中加入一定量的光稳定剂(UV-791),合成改性聚己内酰胺(PA6)树脂.研究了UV-791对PA6光稳定性、热氧稳定性、末端氨基含量的影响.结果表明,UV-791的加入能明显提高PA6的耐紫外光及热氧稳定性,空气氛围下的起始分解温度提升26℃左右;在185℃空气氛围下老化30 min,改性PA6相对黏度下降百分比极低(UV-791含量0.2％时,相对黏度仅下降了1.3％),热氧稳定性明显得到改善.同时,加入量为0.05％时,端氨基含量提高了7.4 mmol/kg.而UV-791对PA6的熔融温度与结晶温度影响不大.     

Preparation of tea catechins using polyamide

An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K_A^B of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins.     

国内外己内酰胺生产与消费市场研究

分析了国内外己内酰胺生产技术状况和市场消费情况并展望了未来发展前景，由于新建己内酰胺项目耗资巨大，建议国内企业通过消化吸收引进的技术挖潜改造扩大产能，能提高我国自主开发己内酰胺的生产能力。     

己内酰胺的技术进展及市场分析

分析及预测了国内外己内酰胺的生产与消费，综述了己内酰胺工艺技术开发的最新进展，对我国己内酰胺工业的发展提出了建议。     

己内酰胺国内外概况及发展动向

介绍了世界己内酰胺主要工艺技术和生产情况,以及各地市场供需状况;阐述了我国及亚洲己内酰胺发展前景;提出了发展我国尼龙６工业的看法和建议。