柑橘皮中精油的提取工艺优化

通过单因子和正交试验对橘皮精油的提取进行了优化,优化工艺为:采用挥发油提取装置蒸馏对橘皮精油进行提取,原料粉碎度为40目,蒸馏瓶中加入2.0%的NaCl,蒸馏时间为60 min,优化后橘皮精油的收率达到2.19%。     

从浓海水中提取氢氧化镁及改性研究

以浓海水为原料、氢氧化钠为沉淀剂,MOA-9P、硬脂酸钠、十二烷基磺酸钠为改性剂一步合成改性氢氧化镁。通过单因素实验表明MOA-9P添加量3.0%、温度65℃、反应240 min;硬脂酸钠添加量4.0%、温度80℃、反应180 min;十二烷基磺酸钠添加量1.5%、温度70℃、反应210 min改性效果最佳。粒度分析表明改性氢氧化镁粉体分散性明显增强平均粒径降低了8μm。     

Effects of acid treatment on adhesive performance of encapsulated aluminium pigments on plastic sheets

In this study, aluminium pigments were encapsulated with hydroxyl group‐containing acrylic resin after surface acid treatment to enhance their adhesive performance in the paint film. The removal efficiency of fatty acid on surface of aluminium particles was studied by means of thermogravimetric analysis and the effect of acid treatment on adhesive performance of aluminium pigments encapsulated with hydroxyl group‐containing acrylic resin in the paint film was investigated by pulling‐off tests. It was found that fatty acid on surface of aluminium particles was removed efficiently by acid ethanol solution, and then hydroxyl group‐containing acrylic resin can be encapsulated onto the surface of the aluminium particles by chemisorptions. The encapsulated aluminium pigments have excellent adhesive performance in the paint film. © 2011 Canadian Society for Chemical Engineering     

Tracer‐compatibilizer: Synthesis and applications in polymer blending processes

This article reports on a route to synthesizing fluorescent labeled graft copolymers, on the one hand; and on a concept of tracer‐compatibilizer for facile build‐up of emulsification curves of polymer blends, on the other hand. For these purposes, blends composed of polystyrene (PS) and polyamide 6 (PA6) are chosen. The synthesis of the corresponding tracer‐compatibilizer consists of three steps: (1) copolymerization of styrene with 3‐isopropenyl‐α,α'‐dimethybenzyl isocyanate (TMI); (2) conversion of a fraction of the isocyanate moieties of the resulting copolymer into anthracene ones upon reacting with 9‐(methylamino‐methyl)anthracene (MAMA); and (3) polymerization of ε‐caprolactam (CL) from the remaining isocyanate moieties. The resulting fluorescent labeled graft copolymer, denoted as PS‐g‐PA6‐Ant, is used to build up emulsification curves of PS/PA6 blends in a twin screw extruder (TSE), showing great usefulness of the concept of tracer‐compatibilizer. POLYM. ENG. SCI. 2012. © 2011 Society of Plastics Engineers     

Application of a novel halogen‐free intumescent flame retardant for acrylonitrile‐butadiene‐styrene

A novel intumescent flame retardant (IFR), containing ammonium polyphosphate (APP) and poly(tetramethylene terephthalamide) (PA4T), was prepared to flame‐retard acrylonitrile‐butadiene‐styrene (ABS). The flame retardation of the IFR/ABS composite was characterized by limiting oxygen index (LOI) and UL‐94 test. Thermogravimetric analysis (TGA) and TGA coupled with Fourier transform infrared spectroscopy (TG‐FTIR) were carried out to study the thermal degradation behavior of the composite and look for the mechanism of the flame‐retarded action. The morphology of the char obtained after combustion of the composite was studied by scanning electron microscopy (SEM). It has been found the intumescent flame retardant showed good flame retardancy, with the LOI value of the PA4T/APP/ABS (7.5/22.5/70) system increasing from 18.5 to 30% and passing UL‐94 V‐1 rating. Meanwhile, the TGA and TG‐FTIR work indicated that PA4T could be effective as a carbonization agent and there was some reaction between PA4T and APP, leading to some crosslinked and high temperature stable material formed, which probably effectively promoted the flame retardancy of ABS. Moreover, it was revealed that uniform and compact intumescent char layer was formed after combustion of the intumescent flame‐retarded ABS composite. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

微电解联合Fenton氧化-混凝沉淀法预处理医药中间体废水的小试研究

针对某医药中间体废水成分复杂,有机物浓度高,具有生物抑制性,废水可生化性差等特点,对其进行了铁碳微电解联合Fenton氧化-混凝沉淀预处理试验研究。通过正交试验进行了微电解过程中铁碳比、反应停留时间、pH、铁粉投加量等参数的优化,COD的去除率为29.1%。结合后续Fenton氧化与混凝沉淀试验,当H2O2投加量为8%,适当调节混凝pH,整个预处理系统出水COD去除率达45.0%,总磷的去除率达77.1%,盐度去除率为24.8%,色度去除率高达95%,可生化性提高至0.29,为后续综合污水的生物处理提供了有利条件。     

有机锡对双酰胺改性环氧聚氨酯树脂阴极电泳漆的影响

采用环氧聚氨酯树脂作为主体树脂,有机锡(二辛基氧化锡,DOTO)为催化剂,制备了阴极电泳漆,并对电泳原漆和漆膜的物理化学性能进行了考察。实验结果表明:电泳原漆的贮存稳定性良好,在50℃热加速试验中,贮存1个月无沉淀、无絮凝、无增稠、细度<15μm。所得漆膜的耐溶剂性、凝胶含量、机械性能、耐盐雾性等良好。     

Enhanced shape memory effect of poly(L-lactide-co-ε-caprolactone) biodegradable copolymer reinforced with functionalized MWCNTs

Data from comprehensive thermomechanical tests of poly(L-lactide-co-ε-caprolactone) biodegradable shape memory polymer (SMP) reinforced with pristine and functionalized multiwalled carbon nanotubes (MWCNTs) are reported. The SMP specimens tested up to 500% strain and between 25 °C and 70 °C temperatures. The incorporation of functionalized MWCNTs leads to the best overall reinforcing effect in tensile modulus, yield stress, tensile strength and elongation at failure. Thermo mechanical experiments resulted that the functionalized MWCNTs increased the glass transition range of composites and changed the melting point of composites slightly. The crystallinity of composites was increased with increment of MWCNTs in composites. The shape fixity and shape recovery of composites increased slightly, while the recovery stress increased 46%. It is found that the functionalized MWCNTs prepare an effective physical cross linking and switching segments in polymer composites.     

Exergy analysis of two-stage steam-water jet injector

Exergy analysis is used as a tool to evaluate exergy losses in the steam-water jet injector so as to improve its overall performance. What this article addresses here is mainly about a parametric study on the injector under various operating conditions, such as different inlet water temperature, inlet steam pressure, pressure ratio, entrainment ratio and flowrate ratio. In addition, the irreversible losses in the component parts of the two-stage injector were analyzed in detail. The results show that the operating parameters have great effects on exergy efficiency of the injector. The average exergy efficiency of the two-stage injector is 21% more than that of the single-stage one. Moreover, calculations based on experimental data indicate that the highest exergy losses due to irreversibility occur in the first-stage mixing chamber. In light of this comparison, the exergy losses occurring in the system are proportional to the exergy efficiency obtained by applying the system.     

聚丙烯纤维染色改性方法研究进展

介绍了聚丙烯纤维染色改性的各种方法及其对纤维性能的影响,综述了各种改性方法的优缺点,重点阐述了高聚物共混改性的研究成果和最新进展。