Acid-catalysed Hydrolysis of Type 3 Dye-Fibre Bonds between Cellulose and Triazinyl Reactive Dyes

The kinetics of the acid hydrolysis of Type 3 dyeings produced by the reaction of dichlorotriazinyl aminoazo dyes with cellulose have been studied at 40°C. A marked effect has been observed owing to what are believed to be localised pH effects, i.e. a non-uniform distribution of hydrogen ions within the fibre phase owing to the localised charges on the dye molecules attached to the fibre. Variation of the ionic strength in the reaction medium does not affect the bimolecular rate constants for the hydrolysis, but brings about changes that can also be ascribed to pH effects in the fibre phase. There is evidence for two kinds of Type 3 dye-fibre bonding, giving a very rapidly hydrolysed species, present in relatively low concentration, and a more stable species.     

Further Studies of the Acid-catalysed Hydrolysis of Type 3 Dye-Fibre Bonds between Cellulose and Triazinyl Reactive Dyes

Improved experimental methods have shown that the conclusions drawn in earlier work [1, 2] are only partially correct. The kinetics of hydrolysis of Type 3 dye-fibre bonds have been shown to be complex and not first-order as believed. The reason lies in the variation of the internal pH of the fibre as dye is removed. Redetermined bimolecular hydrolysis constants for H-acid derivatives show that the more ready hydrolysis of Type 3 dyeings from red H-acid dyes is associated with the formation of a highly active species in the internal pH region 3-3.5. The problems these findings pose for the establishment of a ‘bleaching’ test are raised.     

过氧化氢处理工业废水研究进展(续)

8 处理其他废水 H2O2可处理的其他废水种类繁多,列举于下。广东工业大学徐劲等人研究用Fenton试剂法处理选矿废水中残余的黄原酸盐（黄药）,考察了影响降解效果的因素。在选定条件下,黄药去除率可达99．5％。西北工业大学吴耀国等人研究了废水溶液化学组分对O3／H2O2降解TNT的影响,结果表明,HCO3^-、HCOO^-、Cu^2＋对TNT降解有抑制作用;而Al^3＋则有促进作用。另外,     

过氧化氢处理工业废水研究进展

介绍过氧化氢（H2O2）处理工业废水的研究新进展,特别是国内研究进展。处理方法包括Fenton试剂（H2O2＋FeSO4）、UV／H2O2、O3／H2O2、UV／TiO2／H2O2、活性炭／H2O2等方法。处理的化学污染物主要包括硫化物、氰化物、酚类、染料及中间体、农药、焦化产物及其他杂类。处理效果主要表现在COD、TOC、色度等指标的降低和可生化性能的提高。H2O2处理废水既可独立地进行,直至达标,也可作为其他方法（如生化法等）的前期预处理或后续精处理,目标也是处理达标。简要介绍了H2O2在环保应用中的总体概况及今后展望。     

Dye-Fibre Bond Stabilities of Some Reactive Dyes on Silk

57th Communication on Investigations in Textile Chemistry, for 56th Communication see ref. J. Silk was dyed with twelve reactive dyes containing various reactive groups. The dyeings were thoroughly extracted so that all non-covalently bonded dye was removed. The extracted dyeings were treated with buffer solutions in the pH range 1.89 to 10.65 at 70°C for 24 h. The exhaustion, fixation ratio and extent of reaction of the dyeings and the rate of hydrolysis of all dyed samples in six buffers were measured. The dye-fibre bond was found to be sufficiently resistant to hydrolysis for ail dyeings. The fixation ratio and wet fastness were particularly good for dyeings with α-bromoacrylamide groups and with difluorochloropyrimidine groups.     

过氧化物氧化法制取邻苯二酚与对苯二酚

概述邻苯二酚、对苯二酚的市场前景、生产方法。着重介绍用过氧化氢和过氧化羧酸作羟基化剂 ,使苯酚羟基化生成邻苯二酚和对苯二酚的研究开发进展。     

新一代结合剂

探讨了新一代结合剂,为某些耐火材料提出了应用新型结合剂的建议。     

Ageing of Adhesive Bonds with Various Surface Treatments, Part 1: Aluminium-Dicyandiamide Cured Epoxy Joints

Ageing studies on adhesive-bonded aluminium-dicyandiamide cured epoxy joints prepared using a variety of different surface treatments were carried out using 100% humidity and cycling the joints between 42-48-42 °C every hour. The pretreatments include a chromic acid, silica/siloxane pretreatment, nonrinse chrome pretreatment, titanium/zirconium (Ti/Zr) pretreatment, and anodised substrate with no pretreatment. Dielectric spectroscopy measurements were used to characterise the rate of the water uptake and monitor the conversion of the surface oxide to hydroxide. These data were correlated with the changes that occurred in the mechanical strength of the bonds. The changes in the surface structure were observed using electron microscopy and elemental analysis conducted using X-ray photoelectron spectroscopy. The dielectric permittivity changes observed were similar for all the different pretreatments, indicating that the predominant process was water absorption. However, small differences were observed that reflect the different surface treatments used. Ageing at an elevated temperature of 70 °C provided definite evidence of hydration of the surface oxide layer. Electron microscopy of the fracture surface indicated oxide-to-hydroxide conversion and was reinforced by X-ray photoelectron spectroscopy. Predominantly, the changes in the mechanical strength observed at low temperature are consistent with the plasticization of the adhesive. However, at the elevated temperature of 70 °C, evidence for weakening of the interfacial layer by hydration becomes evident as a reduction in the mechanical strength. The dielectric measurements allowed the changes in the bond to be followed nondestructively. The mechanical strength of the etched-only pretreatment aged surprisingly well and at the lower temperature of ageing was comparable with the no-rinse chrome and titanium/zirconium pretreatments. The least durable was the PT2Cr-free treatment; however, all treatments showed a significant level of durability at low temperature.     

离子选择电极法测定过氧化氢中的硝酸盐含量

开发了用离子选择电极法测定过氧化氢中硝酸盐含量的实验方法。从试样分解条件、pH值与回收率关系试验、定量方法等进行了探讨。精密度试验表明5次测定结果标准偏差为4.61%;回收率在96~100%。跟比色法结果对照,两者数据相近。本方法操作简便、快捷。     

水解油茶饼粕制取酸洗缓蚀剂

用盐酸水解法由油茶饼粕制得了缓蚀剂，测定了Ａ３钢样在ＨＣｌ和Ｈ２ＳＯ４溶液中的缓蚀效率。用动电位扫描法测定了相应条件下的极化曲线，并简要探讨了它的缓蚀作用机理。     

过氧化钙的应用

本文综述过氧化钙在农业种植、水产养殖、食品保鲜、医用药物、环境保护等方面的应用。     

Ageing of Adhesive Bonds with Various Surface Treatments, Part 2: Acrylic Modified Amine-Cured Epoxy Resin

Ageing of adhesive-bonded aluminium-diglycidyl ether of bisphenol A based aliphatic amine-cured acrylic modified epoxy resin reinforced with fused silica exposed to 100% humidity and cycled between 42-48-42 °C every hour is reported. Moisture uptake was followed using broadband dielectric measurements. It was found that the adhesive absorbs moisture very rapidly, the adhesive undergoes significant swelling, and there is a consequent reduction in strength consistent with plasticization of the matrix. The dielectric measurements parallel closely the changes occurring in the adhesive bond line and provide a nondestructive method for monitoring the changes in bond strength. The changes that occur are dominated by the effects of moisture on the adhesive, various pretreatments have little effect on the ageing process, and interfacial failure in this case does not make a significant contribution to the failure of these joints.     

过氧化氢氧化法合成四氯苯醌的研究

以对苯二酚,过氧化氢,盐酸为原料,以盐酸与醋酸(比例为2∶3)为溶剂,间歇滴加过氧化氢,阶梯程序升温反应,反应分别在45℃、70℃、95℃三阶段进行,原位生成氯气氯化合成四氯苯醌。合成四氯苯醌的收率和纯度都可达97%     

过氧化氢及其精馏浓缩

根据过氧化氢精馏浓缩的特点,介绍一种节能和安全型的精馏流程及高新填料精馏塔。     

Ageing of Adhesive Bonds with Various Surface Treatments, Part 3: Aluminium-Dicyandiamide Cured Aluminium Filled Epoxy Joints

Ageing of adhesive-bonded aluminium-dicyandiamide cured epoxy alumina-filled joints prepared using a variety of different surface treatments and exposed to elevated temperatures and high humidity are reported. The uptake of moisture was followed using broadband dielectric spectroscopy, and attempts are made to correlate these changes with observations of variations in the mechanical properties and surface structure monitored by electron microscopy. It was found that the absorption of moisture, as indicated by the dielectric measurements, is similar for all the joints. Small differences observed may be ascribed to the influence of the pretreatment on the absorption behaviour. There was no evidence of changes in the oxide layer of the substrate. Detailed electron microscopic examination of the surfaces did indicate, after prolonged exposure, that change in the pretreatment is consistent with small differences in the dielectric data. Predominantly, the changes that were observed in the mechanical strength of the joints are consistent with the plasticization of adhesive in the joint rather than failure at the substrate interface. Ageing at 70°C did, however, indicate that there were changes in the interfacial layer and these can be correlated with the change in the failure mechanism. It was also observed that the titanium/zirconium (Ti/Zr) pretreatment showed signs of being less durable than the others used in this study.     

湿式氧化法处理厌氧废水实验研究

经化学分析糖蜜酒精废液厌氧制沼气废水水质：CODCr：34507.9mg/L 34507．9mg／L、TOC：8600mg／L,色度大且有恶臭气味。采用双氧水作氧化剂和废水中过量Fe^2＋组成Fenton试剂湿式氧化处理该废水。实验显示：在20min内,CODcr和TOC去除率分别可达97．2％和85.5％,而且能够同时脱色和除臭。湿式氧化处理的效果和速度受反应温度、双氧水投加量、废水初始pH值等因素的影响．但pH值是最敏感的因素。较理想条件是：106℃、双氧水理论用量的2倍和pH值为2-4。     

Flash Photolysis of Hydrogen Peroxide I: The Reaction of Ozonide with Hydrogen Peroxide

The photochemistry of basic aqueous solutions containing hydrogen peroxide and oxygen has been investigated by the flash photolysis method. The decay of O₃^? was followed at 4300 Å over the pH range 13 – 13.7 as a function of hydrogen peroxide and oxygen concentrations. The decay was found to be of the first order under all conditions ?[d(O₃)^?/dt] = k_obs[O₃^?]. The pseudo first-order rate constant k^obs was found to be dependent on H₂O₂ and O₂ concentrations. A mechanism which is consistent with the experimental results is suggested.     

过氧化钙的生产和应用

介绍了过氧化钙的两种生产方法——氯化钙法和氢氧化钙法。并从农业、废水处理、涂料、矿物加工、化学工业等方面阐述了它的主要用途。