A STUDY ON THE ADSORPTION OF LOW CONCENTRATION FREE ALKALI BY SUBACID RESIN

The absorption of free alkali at low concentration by subacid resin was traced with electric conductance method,the effect of temperature on the adsorption,the activation energy of adsorption (Ea) and interaction energy(U) was studied.The result showed that,the process of low concentration alkali adsorption by subacid resin was in accordance with mechanism of monomolecular layer absorption,in addition,with the increasing of temperature,the interaction energy between adsorbate and sorbent increase,so did the surface adsorption rate(k),and linear correlation existed between interaction energy(U) and temperature(T).     

STUDY ON THE DETERMINATION OF TRACE Fe(Ⅲ) BY THIN LAYER RESIN PHASE SPECTROPHOTOMETRY

A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717# resin, then Fe(Ⅲ) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×104L/mol. cm, which is 16 times higher than that of liquid phase spectrophotometry, most coexisting ions do not influence the determination. The detection limit for Fe(Ⅲ) is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe(Ⅲ)]. The calibration curve is linear in the range of 0～25μg/50mL. The preposed method was applied to the determination of Fe(Ⅲ) in water sample with satisfactory results.     

Synthesis and characterization of a novel liquid‐crystalline epoxy resin combining biphenyl and aromatic ester‐type mesogenic units

A novel liquid‐crystalline epoxy resin combining biphenyl and aromatic ester‐type mesogenic units, diglycidyl ether of 4,4′‐bis(4‐hydroxybenzoyloxy)‐3,3′,5,5′‐tetramethyl biphenyl, was synthesized. Its spectroscopic structure, thermal properties, and phase structures were investigated with NMR, differential scanning calorimetry (DSC), and polarized light microscopy (PLM), respectively. The curing agent, diaminodiphenylsulfone, was chosen to investigate the curing behavior by means of DSC and PLM during isothermal and nonisothermal processes. Only one exothermal peak appeared in the isothermal DSC curves. Birefringence was also observed during the curing processes and preserved after postcuring. Compared with short rigid‐rod and flexible epoxies, the cured liquid‐crystalline epoxy resin that was obtained displayed special thermal stability according to thermogravimetric analysis because of its long rigid‐rod mesogenic unit and bulky methyl groups. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 727–735, 2007     

Modification of sulfonated poly(ether ether ketone) with phenolic resin

Soluble phenol formaldehyde resin containing hydroxymethyl groups has been used to modify sulfonated poly(ether ether ketone) (SPEEK). Modification has been carried out with films containing both the polymers and using dimethyl formamide (DMF) as casting solvent at various temperatures under reduced pressure. Associated solvent and the hydrogen‐bonded by‐product dimethyl amine (DMA) were removed through mild alkali–acid–water treatment. Cured and treated films show good and consistent mechanical properties, water uptake (22–25%), ion‐exchange capacity (1.1–1.5 meq/g) and proton conductivity (125–150 mS/cm) at 30°C and hold promise for application in fuel cells, as indicated by a polarization study in a fuel cell test station. Copyright © 2007 John Wiley & Sons, Ltd.     

Access to the core structure of aurisides by a ring-closing metathesis/transannular ketalisation sequence

A short access to the macrocyclic structure of aurisides has been achieved by combining a ring-closing metathesis leading first to a 14-membered ring and a subsequent transannular ketalisation to build the tetrahydropyran subunit.     

漆酚基环氧丙烯酸酯的合成

以漆酚、环氧氯丙烷、丙烯酸为主要原料,通过两步反应合成了漆酚基环氧丙烯酸酯,其结构经IR表征。较适宜的反应条件为:漆酚基环氧树脂(UE)50mmol,n(UE中的环氧基团)∶n(丙烯酸)=1.00∶0.75,w(三乙胺)=2%,于80℃反应3h,丙烯酸的转化率在94%以上。该反应为一级反应,表观活化能52.7kJ.mol-1,频率因子1.719×104s-1。     

FTIR/ATR study of the copolymerization of diglycidyl ether of Bisphenol A with methyl-substituted γ-lactones catalyzed by rare earth triflate initiators

Mixtures of DGEBA with γ-valerolactone (γ-VL) or α-methyl-γ-butyrolactone (γ-MBL) 2:1 (mol/mol) were cationically copolymerized in the presence of scandium, ytterbium, or lanthanum triflates as initiators. The evolution of the different reactive groups was followed by means of FTIR/ATR spectroscopy. From these experiments, we could detect the coexistence of two unexpected processes: a reversion of the intermediate spiroorthoester formed to the initial products and a depolymerization process, which only takes place in samples with γ-VL, when scandium triflate was used as initiator or when the proportion of ytterbium triflate was increased from 1 to 3 phr. When γ-MBL was used as comonomer no depolymerization occurs which supports the proposed mechanism. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2129–2141, 2007     

Hybrid resins from polyisocyanate/vinyl ester/water glass systems: Structure and properties

Polysilicate modified polyurea/vinyl ester hybrid resins were produced by dispersing water glass (WG) in a mixture of vinyl ester (VE) and polyisocyanate in presence of a liquid phosphate as emulsifier. As styrene-crosslinkable VE resins bisphenol A (BA) and novolac types (N), whereas as polyisocyanate a polymeric methylene diphenyl isocyanate (PMDI) were used. The structure and selected properties of the hybrid resins were determined and compared to those of the neat VEs and polysilicate filled polyurea (denoted as 3P resin). Using VE for resin hybridization, which worked as an additional emulsifier for the WG/PMDI/phosphate system, resulted in a fine particle dispersion of the polysilicate. It was found that the type of VE affected not only the dispersion of WG (and thus of the polysilicate) but also the network formation of the polyurea/VE hybrids and their properties. Information about the structure of the polysilicate filled hybrid resins was gained from dynamic-mechanical thermal analysis (DMTA), scanning electron and atomic force microscopic measurements. It was argued that the resin hybridization yielded a conetwork instead of an interpenetrating one. The properties of the hybrid systems were determined by DMTA, fracture mechanical tests, thermogravimetric analysis and flammability measurements. It was established that the stiffness and resistance to thermal degradation of the initial 3P resin was strongly improved by hybridization with VEs. The fracture toughness (K_c) proved to be less sensitive to the formulation of the hybrid resins. On the other hand, the fracture energy (G_c) and limiting oxygen index experienced a positive deviation from the additivity as a function of the 3P/VE composition, at least in a given range.     

Studies on curing kinetics of a novel combined liquid crystalline epoxy containing tetramethylbiphenyl and aromatic ester‐type mesogenic group with diaminodiphenylsulfone

The curing kinetics of a novel liquid crystalline epoxy resin with combining biphenyl and aromatic ester‐type mesogenic unit, diglycidyl ether of 4,4′‐bis(4‐hydroxybenzoyloxy)‐3,3′,5,5′‐tetramethyl biphenyl (DGE‐BHBTMBP), and the curing agent diaminodiphenylsulfone (DDS) was studied using the advanced isoconvensional method (AICM). DGE‐BHBTMBP/DDS curing system was investigated the curing behavior by means of differential scanning calorimetry (DSC) during isothermal and nonisothermal processes. Only one exothermal peak appeared in isothermal DSC curves. A variation of the effective activation energy with the extent of conversion was obtained by AICM. Three different curing stages were confirmed. In the initial curing stage, the value of E_a is dramatically decreased from ～90 to ～20 kJ/mol in the conversion region 0–0.2 for the formation of LC phase. In the middle stage, the value of E_a keeps about ～80 kJ/mol for cooperative effect of reaction mechanism and diffusion control. In the final stage, a significant increase of E_a from 84 to 136 kJ/mol could be caused by the mobility of longer polymer chains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3922–3928, 2007     

环丁烯砜的精制及其UV-Vis和FTIR光谱分析

利用吸附法,考察了活性炭、离子交换树脂精制环丁烯砜的方案,利用UV-Vis,FTIR,XRD对其进行分析检测,重点对环丁烯砜、环丁砜的FTIR谱图进行了解析.活性炭、离子交换树脂串联去除工业级环丁烯砜杂质的效果最佳.利用精制的环丁烯砜催化加氢,合成出了高纯度的环丁砜,转化率大于99.8%,为工业装置技术改造提供了实验依据.