反应温度对弱碱树脂交换容量的影响

本文探讨了用二甲胺胺化的大孔弱碱性阴离子交换树脂，在胺化过程中，不同的反应温度对树脂强碱基因含量及全交换容量的影响．     

凝胶型苯乙烯系离子交换树脂的强度及抗渗透性的影响因素研究 (I)

本文就单体组成中不同引发剂，链转移剂，环二烯，烯丙基类化合物和氧气等对凝胶型苯乙烯系阳离子交换树脂的强度和抗渗透性的影响进行了系统研究。结果显示，采用0．30％的过氧化2－乙基己酸叔丁酯（OT）和0．01％的过氧化苯甲酸特丁酯（CP）代替过氧化二苯甲酰（BPO作引发剂，或者加入0．02％的链转移剂十二烷基硫醇，均能够在一定程度上改善共聚物珠粒的结构均匀性，提高其合成的离子交换树脂的磨后圆球率和抗渗透性能。     

磺酸型阳离子交换树脂催化合成肉桂酸甲酯

以磺酸型阳离子交换树脂为催化剂，由肉桂酸和甲醇合成了肉桂酸甲酯。考察了反应条件对酯化反应的影响和树脂的催化稳定性。结果表明，肉桂酸的转化率可达９５．５％，且催化剂的性能稳定。     

对氟苯乙烯-二乙烯基苯强酸性阳离子交换树脂的合成及其热稳定性研究

以对氟苯乙烯，二乙烯苯为原料合成了强酸性阳离子交换树脂，考察了磺化反应的工艺条件及卤原子，树脂类型对树脂耐热稳定性能的影响。研究表明，对氟苯乙烯－二乙烯基苯共聚体需用发烟硫酸在110℃才可磺化，大孔磺化对氟苯乙烯－二乙烯基苯树脂在190℃水中20h的磺酸基降解率为24．7％，而普通磺酸树脂的磺酸基降解率为53．3％。     

水中二氧化碳含量对弱碱性阴树脂工作交换容量影响的研究

弱碱性阴树脂用于水的除盐处理时，其工作交换容量的大小与许多因素有关。本文主要就进水中ＣＯ２含量对弱碱阴树脂工作交换容量的影响进行了研究，得出了弱碱性阴树脂工作交换容量受水中ＣＯ２含量影响的一般规律，这为弱碱性阴树脂的应用提供了依据。     

离子交换法在细丙制备中的应用

从动物心脏提取细丙,利用细丙与主要杂质肌红蛋白和血红蛋白的等电点的差别而与树脂亲合力不同,应用阳离子树脂,通过调节pH值和溶液的离子强度而分离纯化细丙。     

Co2+、Zn2+、Cd2+的阴离子交换色谱法分离研究

本文对钴与锌、镉等金属离子的阴离子交换色谱法分离进行了研究．采用201×7型阴离子交换树脂经氧化铵溶液饱和后,在pH＝4．0时,使钴与其它金属离子分离,然后分别用0．02mol／L的盐酸溶液及蒸馏水将锌、镉等金属离子从阴离子交换树脂上洗脱．此法分离效果好,操作简单方便．     

应用阳离子交换树脂催化水解蔗糖Ⅰ.蔗糖非均相催化水解反应动力学

实验选用两种H+型强酸性阳离子交换树脂为催化剂，研究蔗糖在离子交换树脂柱内的非均相催化反应动力学。结果表明，温度每升高10℃，蔗糖在两种离子交换树脂柱内的水解速度分别增加到2．1和3．3倍；蔗糖在两种离子交换树脂柱内水解反应的表观活化能分别为64．96kJ／mol和79．59kJ／mol，其水解反应有明显的扩散控制。     

牛磺酸和甘氨酸在D290树脂上的离子交换平衡

研究了牛磺酸与甘氨酸在阴离子树脂D290上的离子交换平衡.采用静态法分别进行牛磺酸/氢氧根/D290树脂和甘氨酸/氢氧根/D290树脂体系的离子交换平衡实验并测定等温线;在不同的离子强度下进行了牛磺酸/甘氨酸/氢氧根/D290阴离子交换树脂体系的离子交换平衡实验,测定牛磺酸和甘氨酸在碱性条件下的竞争交换平衡等温线.实验结果表明,牛磺酸在D290阴离子交换树脂上的交换量大于甘氨酸的交换量,阴离子交换树脂对牛磺酸和甘氨酸的选择性系数分别为STau-,OH-=2.55,SGly-,OH-=1.65.在牛磺酸/甘氨酸/氢氧根/D290树脂体系中,D290树脂对牛磺酸/甘氨酸/氢氧根3种离子的选择性从高到底顺序是:牛磺酸＞甘氨酸＞氢氧根.树脂对牛磺酸的选择性要大于对甘氨酸的选择性.随着溶液中离子强度的增大,树脂对牛磺酸与甘氨酸之间的选择性下降.     

弱碱性阴离子交换树脂分离1,6—二磷酸果糖的研究

采用弱碱性阴离子交换树脂HJ-30对发酵液中1，6-二磷酸果糖的分离进行了研究。详细地研究了树脂的吸附和脱附性能。实验结果表明，HJ-30树脂对FDP的吸附量达0．28gFDP／g湿树脂，以0．05mol／LNaCl洗脱光机磷和1mol／LNaCl洗脱1，6-二磷酸果糖，产品的收率和纯度分别为92％和99．4％。     

Effect of drying process on structure and property of polyaspartic acid resin

The effect of drying temperature on the physical and chemical structure and water absorbent behavior of polyaspartic acid resin were investigated via methods of infrared spectrum analysis and the electron microscope. The results show that: the heat treatment could result in a damage of the cross-linked bonds and a decrease of the cross-linked degree to the cross-linked polyaspartic acid resin. When the drying temperature exceeded 180°C, both backbone basic skeleton and side chain portions were also damaged heavily and gave off NH₃ in addition to the damage of the cross-linking portions. A relatively fast dehydrating rate at 40°C was in favor of the product with loose, uniform and nondestructive porous network structure to be obtained, which has big porosity and pore size. This kind of product has excellent water-absorbency and gel strength. The gel strength of PASP resin decreased with the increase of the drying temperature. The drying temperature has a greater effect on the swelling ratio and gel strength of the polyaspartic acid resin products with lower cross-linking degree than on that of the polyaspartic acid resin products with higher cross-linking degree.     

THE EFFECT OF IONIC STRENGTH ON THE UPTAKE OF TAURINE ON A STRONG-BASIC ANION EXCHANGE RESIN

1. INTRODUCTION Taurine (NH2CH2CH2SO3H) is one of the most important amino acids in the human body, and plays an important role in a variety of physiological functions, pharmacological actions and pathological conditions, such as in controlling epilepsy, hypertension and arrhythmia. It is also often used to recover osmotic pressure and promote cerebrum growth [1,2]. As one of amino acids, taurine had the amphoteric characteristic which can be utilized in the ion-exchange technique to e…     

Novel toughened cyanate ester resin with good dielectric properties and thermal stability by copolymerizing with hyperbranched polysiloxane and epoxy resin

A novel toughened cyanate ester (CE) resin with good dielectric properties and thermal stability was developed by copolymerizing 2,2′‐bis(4‐cyanatophenyl)iso‐propylidene (BCE) with a combined modifier (HBPSiEP) made up of hyperbranched polysiloxane (HBPSi) and epoxy (EP) resin. HBPSi was synthesized through the hydrolysis of 3‐(trimethoxysilyl)propyl methacrylate. The effect of differing stoichiometries of HBPSiEP on the curing characteristics and performance of BCE resin is discussed. Results show that the incorporation of HBPSiEP can not only effectively promote the curing reaction of BCE, but can also significantly improve the toughness of the cured BCE resin. In addition, the toughening effect of HBPSiEP is greater than single EP resin. For example, the impact strength of modified BCE resin with 30 wt% of HBPSiEP is 23.3 KJ/m², which is more than 2.5 times of that of pure BCE resin, while the maximum impact strength of EP/BCE resin is about 2 times of pure BCE resin. It is worthy to note that HBPSiEP/BCE resins also exhibit improved thermal stability, dielectric properties, and flame retardancy, suggesting that the novel toughened CE resins have great potentiality to be used as a matrix for advanced functional composites or electronic packing resins. Copyright © 2009 John Wiley & Sons, Ltd.     

THE EFFECT OF IONIC STRENGTH ON THE UPTAKE OF TAURINE ON A STRONG-BASIC ANION EXCHANGE RESIN

Studied the effect of ionic strength on the uptake of taurine on a strong-basic anionexchange resin. The batch phase equilibrium experiments of ta urine on the anion exchange resin D290 were conducted at different ionic strength, and then the amounts of uptake of taurine on the resin at different pH were determined. The ion exchange mechanisms of taurine on the anion exchange resin at different pH were discussed. Experimental results showed that with increase of the ionic strength of solution, the adsorbed amount of taurine on the resin D290 decreased; Adding small amounts of NaOH or HCl into the system of taurine aqueous solution/D290 anionresin would make the amount of taurine taken up on the resin to decrease due to the competition uptakes of hydroxyl ion with taurine or the decrease in the amount of absorbable zwitterions of taurine in the solution and excluding the cations of taurine from the anion resin.     

两种不同粒径的SBR粒子对透明ABS树脂力学性能影响

从SBR橡胶粒子出发,采用乳液原位悬浮聚合方法合成了一系列透明ABS树脂.采用小粒径SBR橡胶粒子虽然可以获得透明性良好的透明ABS树脂,但树脂的抗冲性能较差.采用大粒径SBR橡胶粒子ABS树脂的透明性明显下降.采用由粒径分别为400nm和70nm两种SBR橡胶粒子所组成的双峰粒子(指粒度分布谱上有两个峰)体系,当二者比例在4/6~6/4范围内,总橡胶粒子含量为15%~18%时,所得到的透明ABS树脂冲击强度已经达到90~120J/m,透光率超过80%.初步探讨了不同增韧体系的ABS树脂的脆韧转变关系;研究了不同粒径橡胶粒子的协同增韧效应.确定了由SBR双峰粒子增韧体系获得具有良好力学和透光性能的ABS树脂的基本条件.     

茂型金属复合催化丙烯酸酯聚合物多孔材料的研究

以丙烯酸酯类单体、聚合物树脂粉料为主要原料,通过自制乳化剂的水乳液模板法和茂型金属-N,N-二甲基苯胺-过氧化物组成的复合氧化―还原引发体系,混合形成可室温快速聚合成型得到丙烯酸酯聚合物多孔材料的可浇注的悬浮乳液。研究了初始混合温度、搅拌速度和时间对操作工艺的影响和聚合固化过程中的热效应,讨论了聚合成孔机理、水和惰性树脂粉料对多孔材料孔隙和强度的影响、多孔材料的透气透水性能。结果表明,二茂铁比二茂钴、二茂镍、二茂钌等均具有更快的引发速率和单体转化率,在完全活性树脂粉料下成型的多孔材料可具有30 MPa以上抗压强度和40%以上的压缩形变,优异的透气透水性,开孔孔隙率达20%(V/V)以上;并且随着惰性树脂粉料的添加,多孔材料强度韧性和开孔孔隙率明显下降;而随着水用量的增加,开孔材料孔隙率增加,强度下降。     

一种新型室温固化、耐高温环氧树脂体系及其性能

采用1-己基-3-甲基咪唑四氯化铁盐([C₆mim]FeCl₄)与混合胺复配室温(20 ℃)固化双酚A型环氧树脂E-51,并与其它脂肪胺类室温固化E-51体系在力学性能、热性能、耐老化性能方面的数据进行了比较,同时分析了[C₆mim]FeCl₄不同添加量对固化体系性能的影响,结果显示:[C₆mim]FeCl₄/混合胺复配室温固化E-51体系的室温拉伸强度可达90 MPa,高温(120 ℃)下也保持了良好的力学性能,热失重(5%)分解温度为310 ℃,200 ℃老化7 d后,拉伸强度为28 MPa,是一种可在高温下使用的新型环氧树脂室温固化体系。     

Novel photosensitive resin simultaneously with outstanding cryogenic strength and toughness for digital light processing three-dimensional Printing

With the increased demand for three-dimensional (3D) printing technology in various fields, it is important to develop high-performance resin that could withstand temperature changes to expand their application potential. A new photosensitive oligomer (BDM–DDM–ETPS–GMA) based on epoxy-terminated polyether siloxane (ETPS) and bismaleimide diphenylmethane/4, 4′-diaminodiphenylmethane (BDM–DDM) resin was synthesized and then mixed with other oligomers, reactive diluents, and photoinitiators to prepare a novel 3D printing resin. The results show that the resulting resins exhibit good fluidity and rapid photopolymerization ability, which satisfies the rheological prerequisites of 3D printing resin. Moreover, the incorporation of BDM–DDM–ETPS–GMA can simultaneously improve the cryogenic stiffness and toughness of commercial resin. Specifically, the tensile strength, elongation at break, flexural strength, impact strength, and storage modulus at ?30 °C of modified resin with 15% BDM–DDM–ETPS–GMA are 151.2 MPa, 10.9%, 146.2 MPa, 9.8 kJ/m², and 4,131 MPa, respectively, which are about 2.81, 1.70, 1.37, 1.81, and 1.54 times of that of commercial resin. A synergistic enhancement mechanism is believed to be attributed to these results, which includes the introduced flexible siloxane chain and the rigid bismaleimide structure as well as decreased cross-linking density. These attractive features of modified resins suggest that the method proposed herein is a new approach to develop high-performance 3D printing photosensitive resin simultaneously with outstanding cryogenic strength and toughness and thus has wide application potential in the aerospace, military industry, and other cutting-edge fields.     

Fire Retardancy of Aluminum Hydroxide Reinforced Flame Retardant Modified Epoxy Resin Composite

A novel phosphorous containing flame retardant epoxy resin is synthesized by modifying the epoxy resin initially with phosphoric acid and further with aluminum hydroxide (ATH) to enhance the fire retardancy of the modified epoxy resin. The several phosphorous modified epoxy resin to ATH mass ratios were used to study the effect of ATH addition on epoxy. Thermal and mechanical properties. The structure of the modified flame retardant epoxy resin was characterized using Fourier-transform infrared spectroscopy (FTIR) while thermal degradation behavior and flame retardant properties were examined using thermo-gravimetric analysis (TGA) and UL-94 testing. Furthermore, ultimate tensile strength and young modulus were analyzed to study the effect of ATH addition on mechanical properties. The findings indicated that fire retardancy of ATH reinforced modified ep oxy resin is higher than virgin and phosphorous modified epoxy resin and depicted eminent flame retardant properties with suitable mechanical properties.

     

稀释剂对耐高温环氧树脂性能的影响

采用3,4-环氧环己基甲基-3,4-环氧环己基甲酸酯(2010P)作为N,N,N',N'-四环氧丙基-4,4'-二氨基二苯甲烷环氧树脂(AG-80)/六氢苯酐(HHPA)固化体系的稀释剂。 通过粘度、拉伸、高温剪切、示差扫描量热法(DSC)以及高倍显微镜等技术手段及方法,考察稀释剂含量对环氧树脂的粘度、力学性能和热性能的影响,研究了稀释剂与环氧树脂之间的相互作用。 结果表明,2010P可以显著提高树脂的流动性。 随着2010P含量的增加,体系的拉伸强度会呈现先上升后下降的趋势,在质量分数25%时达到最大值。 DSC结果显示,2010P的加入会降低AG-80的玻璃化转变温度,但适量的加入可以进一步提高AG-80环氧树脂在高温条件下的粘接性能。 当2010P的质量分数为30%时,树脂在200 ℃的剪切强度可达到13.78 MPa。