高分子材料抗氧剂的抗氧机理及发展趋势

综述了受阻酚、受阻胺传统抗氧剂的种类和抗氧机理,重点介绍了非受阻酚类抗氧剂的分子结构特点和作用机理。并指出抗氧剂的发展趋势是向着多功能化、反应型、高分子量化和安全化方向发展。     

含受阻酚侧链的聚氨酯阻尼性能研究

将二缩三乙二醇双〔β-(3-叔丁基-4-羟基-5-甲基苯基)丙酸酯〕(抗氧剂245)羧基化,得到具有一定反应活性的受阻酚基团,通过与多苯基多甲基多异氰酸酯(20S)的反应,合成带受阻酚侧链的多异氰酸酯,制备受阻酚型聚氨酯阻尼材料;讨论了羧基受阻酚及其含量、作为阻尼填料的抗氧剂245以及nNCO/nOH对聚氨酯材料阻尼性能的影响。结果表明,引入羧基受阻酚基团,聚氨酯材料的阻尼性能有很大的提高,并随引入的羧基受阻酚含量的增加而提高;当羧基受阻酚占20S质量分数为21.9%时,提高阻尼填料抗氧剂245的含量、减小nNCO/nOH,聚氨酯材料的阻尼性能增加。     

受阻酚类抗氧剂的研究进展及发展趋势

介绍了受阻酚类抗氧剂的作用机理和分类,综述了受阻酚类抗氧剂的研究概况,并对各种类型的受阻酚(单酚型,双酚型,多酚型以及复合型)作了详细的介绍,同时指出受阻酚类抗氧剂的发展趋势,强调应加强受阻酚类抗氧剂的研究。     

非对称型受阻酚抗氧剂的结构与作用特点及应用技术

分析了非对称型受阻酚抗氧剂的结构和作用特点,说明了非对称型受阻酚抗氧剂反应活性更大,反应速度较快,色泽保护性好,热氧稳定效率高。国内非对称型受阻酚抗氧剂的现有消费量很低,有较好的应用前景。     

测氧法研究受阻酚抗氧剂的抗氧化活性及反应动力学

采用测氧法考察了4种市售受阻酚抗氧剂的抗氧化活性,同时对其清除ROO·反应进行了动力学分析。结果表明:4种受阻酚抗氧剂对ROO·均具有良好的清除作用,并且抗氧化活性随着酚羟基浓度增加而增大。在同等的酚羟基浓度下,抗氧剂的抑制速率常数kinh值从大到小的顺序为抗氧剂1098、抗氧剂BHT、抗氧剂1010、抗氧剂1076。抗氧剂的抗氧化活性与功能基团的个数和对位取代基的供电性密切相关,酚胺复合型抗氧剂体现出更高的抗氧化活性。     

聚合型多功能光稳定剂的合成研究

设计并通过以3,5-二叔丁基-4-羟基苯甲醛为原料,经与正丁胺还原胺化,与三聚氯氰取代反应,最后与N,N-双（2,2,6,6-四甲基-四哌啶基）己二胺进行聚合反应,得到了含有受阻胺和受阻酚活性基团的多功能聚合型光稳定剂化合物。     

聚合型受阻酚抗氧剂的研究进展

综述了以双环戊二烯、对甲苯酚和异丁烯为原料生成聚合型受阻酚抗氧剂CPL的反应机理、国内外文献报道的典型制备方法及应用情况。指出了聚合型受阻酚抗氧剂的发展趋势,强调了应加强此类抗氧剂的研究。     

HALS研发进展及其在PVC中的应用

介绍了近年来受阻胺类光稳定剂(HALS)新产品的研究开发情况,高分子量化受阻胺、多功能化受阻胺、低碱性化受阻胺和反应型受阻胺等不断出现;应用研究取得新进展,对PVC体系中有较好稳定的作用。     

非对称型受阻酚类抗氧剂的研究新进展

非对称型受阻酚类抗氧剂以其特殊的结构显著提高了聚合物的抗氧化效率,新型非对称型受阻酚的探索与开发代表了当今世界聚合物抗氧化领域的一大发展趋势。简述了非对称型受阻酚类抗氧剂的结构特性及抗氧化机理,重点介绍了几种典型的半受阻酚类抗氧剂的合成及应用,指出了非对称型受阻酚类抗氧剂的研究方向。     

农用棚膜耐老化体系开发应用进展

综述了农用棚膜耐老化体系发展概况 ,重点阐述了高分子量聚合型受阻胺光稳定剂与复合型抗氧剂、复合聚合型受阻胺光稳定剂与复合抗氧剂组成的聚烯烃棚膜耐老化体系及其应用效果 ,简要介绍了抗农药型受阻胺光稳定剂开发应用情况 ,并对光学性能稳定化的研究提出了看法。     

Study of the reaction between dimethyl phenols and formaldehyde in alkaline medium

The reaction of several dimethyl phenols with formaldehyde in alkaline medium was investigated. The addition products were separated by means of high pressure liquid chromatography and identified using IR and NMR spectroscopy. 2,3-dimethyl phenol yields four, 2,4-dimethyl phenol one, 2,5-dimethyl phenol four, 2,6-dimethyl phenol one, 3,4-dimethyl phenol three, and 3,5-dimethyl phenol five addition products. 3,5-dimethyl phenol was the most reactive, 2,6-dimethyl and 2,4-dimethyl phenols the least reactive species. Rate constants for individual reactions were obtained from the dependence of concentrations on the reaction time.     

Reaction of 3-methyl phenol with tung oil

The aromatic ring substitution reaction of 3-methyl phenol with tung oil under acidic conditions was carried out. The product was analyzed to find out if 3-methyl phenol was subjected to the ring substitution reaction with tung oil at its conjugated double bonds. Up to two molecules of 3-methyl phenol were addition-reacted with the conjugated triene of one eleostearyl group of triglyceride of α-eleostearic acid which is the major component of tung oil. The 4-position of 3-methyl phenol was preferentially subjected to the cresol's ring substitution. Therefore, up to 6 mol of 3-methyl phenol was added to 1 mol of tung oil, most of which was bonded to 3-methyl phenol at its 4-position. When 3-methyl phenol was reacted with a relatively large amount of tung oil, the substitution reaction occurred at the 6-as well as 4-position of 3-methyl phenol to yield a tung oil dimer having 3-methyl phenol units in its molecule. The above results were confirmed by infrared (IR), nuclear magnetic resonance (NMR), and high-speed liquid chromatographic (HLC) analyses.     

Modélisation de la cinétique de biodégradation de phénol par granules aérobies

This work describes a model of the biodegradation of phenol carried out by aerobic granules. These granules were obtained by culturing an activated sludge supernatant in a sequencing batch reactor fed with a synthetic waste water and subsequently, by acclimation to phenol (100 mg/L). The kinetics of phenol biodegradation by the aerobic granules was investigated over a wide range of initial phenol concentrations (40–1112 mg/L) in shake‐flask cultures. A Haldane‐type model was adjusted to the experimental results, which depicts successfully the phenol biodegradation profiles in the entire range of initial concentrations studied by using only one set of parameters. It is our view that the proposed model could contribute to the knowledge about the ability of aerobic granular systems to biodegrade toxic, inhibitory compounds such as phenol.     

Oxidation of phenol in a bioremediation medium using chlorine dioxide

BACKGROUND: High concentrations of phenol in wastewater are difficult to remove by purely biological methods. Chemical oxidation is one way to treat high concentrations of phenol but complete oxidation will make the treatment process uneconomical. For the purpose of integrating chemical and biological treatment, the oxidation of phenol using chlorine dioxide was investigated in a medium suitable for bioremediation. The effects of chlorine dioxide concentration (500 to 2000 mg L^?1), temperature (10 to 40 °C) and pH (3 to 7) on the oxidation of 2000 mg L^?1 of phenol were determined. RESULTS: Chlorine dioxide concentration was found to be the dominant parameter for the removal of phenol in the nutrient rich medium. The optimal concentration of chlorine dioxide to completely oxidize 2000 mg L^?1 of phenol was 2000 mg L^?1. Compared with Fenton's reagent, half as much chlorine dioxide was needed to oxidize 2000 mg L^?1 phenol. The reaction of chlorine dioxide with phenol was very fast and reached equilibrium within 10 min. The main oxidation products were identified as 1,4‐benzoquinone and 2‐chloro‐1,4‐benzoquinone. CONCLUSION: Compared with Fenton's reagent, chlorine dioxide is a superior oxidant for removal of phenol from both pure water and bioremediation medium. Copyright © 2010 Society of Chemical Industry     

脱除苯酚中微量杂质的工艺技术进展

简要介绍了苯酚精制过程中含有微量的有机杂质异亚丙基丙酮、羟基丙酮、苯并呋喃的形成机理,及其对苯酚产品质量的影响,并概述了分别使用水滑石型材料（HTM）、ⅥA族金属改性的氧化铝、沸石、酸性离子交换树脂为催化剂的一步苯酚精制法和使用酸性树脂＋闪蒸法和两步固体酸法的两步精制法脱除苯酚中羟基丙酮、亚丙基丙酮、苯并呋喃等微量有机杂质的生产技术的新进展。     

光催化氧化法处理含酚废水研究

以苯酚为模型化合物，对紫外光照射下含酚废水的光催化降解行为进行了研究。四种不同产地的TiO2被选择为光催化剂。实验结果表明苯酚初始浓度100mg／L，TiO2加入量80mg／100mL溶液，反应100min条件下，苯酚转化率达96％。含有少量金红石型TiO2的锐钛型TiO2的光催化活性最高。100mL 100mg／L的苯酚溶液中最佳的TiO2加入量为80mg。苯酚初始浓度低于100mg／L条件下，苯酚光催化降解反应速率遵循表观一级反应速率方程。     

Phenol biodegradation in a bioreactor considering different geometries and process parameters

In this study, a three-dimensional coupled lattice Boltzmann model and cellular automata platform was developed to simulate biofilm growth and phenol biodegradation as an effective and sustainable way to remove phenolic contaminants in aquatic systems. Two three-dimensional bioreactors with cubic or spherical obstacles at varying inlet phenol concentrations and flow velocities were examined. The results showed that the cubic-bioreactor had higher phenol reduction than the spheric-bioreactor due to the greater effects of cubic obstacles on flow patterns. The biofilm concentration in bioreactors decreased up to 36.4% as inlet velocity increased and in the spheric-bioreactor at the same inlet phenol concentration. The cubic-bioreactor had the highest normalized reduction rate of 1.194 at the lowest inlet phenol concentration, while the spheric-bioreactor had the lowest one of 0.871 at the highest inlet phenol concentration. The results proved the accuracy of the model to assess the performance of wastewater treatment bioreactors under different conditions.     

Three-phase reactors for environmental remediation: catalytic wet oxidation of phenol using active carbon

Wet oxidation of phenol aqueous solutions was carried out in a fixed bed reactor operating in trickle flow regime. Mild conditions of temperature (140°C) and oxygen partial pressure (1–9 bar) were used. Three active carbons and one commercially available supported copper catalyst were tested as catalytic material. Previous studies demonstrated that active carbon gives higher phenol conversion than conventional oxidation catalysts, although significant loss of active carbon due to combustion was also found. In the present study, the combustion of the active carbon during the process is highly reduced by lowering the oxygen partial pressure from 9 to 2 bar, maintaining an acceptable phenol conversion. The comparison of the performance of three different active carbons shows that their physical and chemical characteristics largely influence on the phenol conversion achieved.     

Preliminary Study on Chicken Feather Protein–Based Wood Adhesives

Abstract

The objective of this preliminary study was to partially replace phenol in the synthesis of phenol-formaldehyde resin with feather protein. Feather protein–based resins, which contained one part feather protein and two parts phenol, were formulated under the conditions of two feather protein hydrolysis methods (with and without presence of phenol during hydrolysis), two formaldehyde/phenol molar ratios (1.8 and 2.0), and three pH levels (9.5, 10.5, and 11.5). Southern pine fiberboard bonded with feather protein–based resins was fabricated and bending strength, bending stiffness, internal bonding strength, and percent thickness swell were evaluated. Results indicated that the test parameters all significantly affected resin quality. The resin formulated with feather protein hydrolyzed in the presence of phenol, using a F/P ratio of 2.0, and at a pH of 10.5 performed as well as the neat PF resin. Based on our findings, feather protein is a potential cost-effective material for the production of PF-type adhesive resins.     

基质穿膜作用对苯酚生物降解动力学的影响

Based on the theory of substrate permeation through the cytoplasmic membrane,and considering the effect of initial concentration of substrate,a new kinetic model of phenol degradation process was proposed,Comparing with the widely used Haldane model,which is greatly dependent on the initial phenol concentration,our model can be used to simulate the phenol degradation process in a wide range of initial phenol concentration by using only one set of model parameters ,Therefore,this new kinetic model has much more potential applications to industrial design and operation.