Dyeing of ramie fiber with C.I. disperse red 74 (DR74) at the temperatures from 343.15 to 403.15 K and under the pressures of 12-20 MPa has been thoroughly investigated using supercritical carbon dioxide (scCO2)as a solvent. Ramie fiber was first treated with alkali and then with benzoyl chloride to improve the affinity and interaction between disperse dye and ramie fiber. The morphological and structure transformations in fiber induced by pretreatment were determined by a Fourier transform infrared spectrometer (FT-IR),X-ray diffraction (XRD),scanning electro-microscopy (SEM),differential scanning calorimetry(DSC),and thermogravimetry analysis (TGA).The modification of ramie fiber with benzoyl chloride was characterized by a degree of substitution (DS).The damage to ramie fiber caused by pretreatment and scCO2 dyeing was determined by stress-strain measurements. The color strength of the fiber was evaluated by K/S measurements. The dyeing effects have been studied by means of time, pressure,temperature,and concentration of dye.

用Benson 基团贡献法计算了碳酸二甲酯(DMC) 的标准摩尔生成焓Δf H0m 、标准摩尔生成吉布斯自由能Δf Gθm 和等压摩尔热容Cp ,m 。计算了不同温度和压力条件下二甲醚(DME) 氧化羰化合成DMC 及DME 与CO2 反应合成DMC 的焓变ΔrHm 、吉布斯自由能变ΔrGm 和平衡常数ln Kθ。计算结果表明:在300～1000 K 的温度及011～30MPa 的压力条件下,由DME 氧化羰化合成DMC 是热力学上可自发进行的反应,而由DME 和CO2 合成DMC 是非自发进行的,需要通过耦合等方式来改变反应途径(或重构反应体系) ,该反应才有可能进行。为由DME 合成DMC 的反应途径设计和催化剂的探索研究提供了热力学依据。

A highly dispersed nanocrystalline rutile powder (NRP) having ultrafine and narrow-distributed diameters was successfully prepared via an improved conventional liquid one-step method by introducing dioctyl sulfosuccinate sodium salt (AOT) surfactant in the peptization reaction anaphase. The average grain size of the product is 10–20 nm. The effects of the titanium tetrabutoxide (Ti(OBu)4) to ethanol volumetric ratio, the precipitation temperature, the peptization temperature and the presence of dioctyl sulfosuccinate sodium salt (AOT) on the preparation of NRP were studied. A new procedure for synthesizing NRP is proposed, and the optimum conditions for preparing NRP were obtained. The TEM, XRD, SEM and FT-IR results were also investigated in this work.

The catalytic synthesis of methyl acrylate by hydroesteri cation of acetylene with methyl formate was studied under various conditions. Mixtures of nickel acetate tetrahydrate, copper sulfate pentahydrate and sodium iodide dihydrate were used as catalysts, and N,N-dimethylformamide as solvent. The experimental results concerning the effects of the reaction condition on selectivity to methyl acrylate, methanol and methyl propionate suggested the synthesis of methyl acrylate through the carbonylation reaction of acetylene. When the reaction was carried out under the total initial pressure of 6.0 Mpa and the CO initial partial pressure of 3.0 MPa at the temperature of 1808C with the catalyst composition of 0.040 M Ni(OAc)2_4H2O and 0.054 M NaI_2H2O, 86% selectivity to methyl acrylate and 64% conversion of methyl formate were achieved. # 1998 Elsevier Science B.V. All rights reserved.

A modification procedure for ramie fiber using 3-chloro-2-hydroxypropyltrimethyl ammonium chloride (CHPTAC) as a cationic agent and NaOH as a catalyst was developed in this paper. The morphological and structutal transformations of the fiber induced by modification were determined by XRD(XRD),differential scanning calorimetry (DSC), and thermogravimetry analysis(TGA).XRD results show that the crystal structure of the modified fiber was still preserved although its crystallinity was decreased, which was confirmed from the TGA results. The mechanisms for the modification and dyeing of ramie fiber were analyzed,and the optimum modification conditions were determind to ba the CHPTAC concentration of 30gL-1, the NaOH concentration of 15gL-1,the reaction temperature of 50℃,and the reaction time of 60 min.The raw and the modified fibers were dyed with C.I. reactive red 2. The K/S values for the cationic modified fiber increased to be three times as high as the unmodified fiber. The dye uptakes increased greatly with an increase in the nitrogen contents up to 0.4% on the modified fibers.