共查询到20条相似文献,搜索用时 15 毫秒
1.
Two series of interpenetrating sulfonic acid resins (ISAR), 10×n and n×10, were prepared by means of the wet method, and the physicochemical, thermodynamic and kinetic properties of the ISAR were measured. The results show: 10×n resins exhibit better properties than n×10 ones, mainly in higher apparent degree of crosslinking and larger conformational entropy effect, among which, 10×1 resin exhibits the best thermodynamic and kinetic properties. In the DTA graphs of n×10 resins, there are two T_g and two T_(ox), but in those of 10×n, only one T_g and one T_(ox). This result well supports the conclusion that 10×n resins have much better interpenetrating structural aspects. 相似文献
2.
在静态平衡条件下, 应用FT-IR和减差光谱技术系统地测定了Poly A薄膜在温度为25±1 ℃、相对湿度从0%到100%的不同情况下的吸收光谱, 波段范围为4000-800 cm~(-1)。根据红外光谱的峰位和强度的变化, 证实了Poly A的水化作用主要发生在碱基中的-NH_2基团和磷酸根基团上。其中-NH_2的光谱强度在相对湿度低于30%时就有明显变化, 是水化较强的基团之一; 而P=0的峰位移最大, 并且在高湿度时出现两个振动频率, 说明有两种不同的水化状态。在水化过程中, 水峰的峰位也有较大变化, 并分裂为多重峰。 相似文献
3.
4.
5.
The effect of polystyrene sulfonic acid (PSSA) macromolecules on the polymerization of acrylamide (AM) has been studied. It was found that the rates of polymerization of AM were greatly increased in the presence of PSSA in the polymerization system.The maximum value of the rate of polymerization of AM was obtained when the ratio of [—SO_3H]: [AM] reached 3:1. When the insoluble crosslinked PSSA was used instead of the soluble one, this effect decreased considerably. The interaction between molecules of PSSA and AM was determined by infrared spectroscopy, elementary analysis and X-ray photoelectron spectroscopy. The combination form, —SO_3-NH_3~ CO—, formed between sulfonic group and amide group was found to be existed since the infrared absorption band of —NH_2 shifted from 3400cm~(-1) to 3150 cm~(-1), the binding energy of electron N_(18) changed from 399.7 eV to 401.3 eV, and the atomic ratio of N to S of the products was similar to the ratio of reagents. Based on these experimental results, the mechanism of AM polymerization in the presence of PSSA is proposed. The initial step is the combination of AM with sulfonic group to form —CONH_3~ , then followed by polymerization on the PSSA macromolecule. The role of PSSA on the polymerization of AM is discussed. 相似文献
6.
7.
对甲苯磺酸催化合成丁酸丁酯的研究 总被引:13,自引:0,他引:13
丁酸丁酯是无色至淡黄色透明油状液体,有成熟香蕉似水果香气.稀释时为菠萝和朗姆酒香气及稀奶油滋味.天然品存在于苹果、香蕉、葡萄、梨、草莓、李、西番果等中.主要用以配制苹果、香蕉、梨和奶油等型香精,是我国GB2760-86规定允许使用的食用香料;也可用于有机合成和用作溶剂.通常它是在硫酸催化下由丁酸和正丁醇酯化反应而得[1-2],硫酸虽活性高,价廉,但选择性差,产品质量不好,设备腐蚀严重,同时产生大量废液,污染环境.因此人们寻求更优良的催化剂来代替硫酸,已发现强酸性阳离子交换树脂、磺酸树脂、固体超强酸、杂多酸以及过渡金属硫酸铜、氯化铁等均可作为酯化反应的催化剂[3-8].但用固体酸催化合成丁酸丁酯至今未见报道.对甲苯磺酸是一种强有机酸,无氧化性,无碳化作用,作为酯化反应的催化剂时,具有活性高,选择性好,产品纯度高,不腐蚀设备,减少污染等优点[9-10].本文利用对甲苯磺酸作催化剂合成丁酸丁酯,讨论了影响反应的因素,在适当的合成条件下,酯化率可达97.8%. 相似文献
8.
2-噻吩乙酸在3种树脂上的吸附行为研究 总被引:15,自引:0,他引:15
通过静态吸附实验 ,研究了XAD 4、NDA 10 0和ND 90吸附树脂对水溶液中 2 噻吩乙酸的吸附热力学及动力学特性 ,结果表明 ,2 噻吩乙酸在XAD 4树脂上是单层吸附 ,符合Langmuir等温吸附方程 ,吸附过程符合准一级动力学吸附方程 .2 噻吩乙酸在NDA 10 0和ND 90树脂上的吸附也能用Langmuir等温吸附方程表示 ,但并不只是单层吸附而主要是由毛细管凝聚和微孔填充作用造成的 ,吸附过程可分为大孔和中孔区的吸附以及微孔区的吸附两个阶段 ,两个阶段都符合准一级动力学吸附方程 相似文献
9.
新型吸附树脂对苯乙酸的吸附热力学研究 总被引:2,自引:0,他引:2
研究了苯乙酸在新型超高交联树脂AH、NDa-150和大孔吸附树脂(Amberlite XAD-4)上的平衡吸附数据,测定了288K、303K和318K温度下的吸附等温线,结果表明吸附过程符合Langmuir吸附等温方程。苯乙酸在AH、NDa-150上的吸附容量分别比在Amberlite XAD-4上的吸附容量最高高出90%、113%,这主要归因于AH、NDa-150表面的极性基团及树脂的微孔结构.Langmuir吸附等温线、相对吸附容量以及等量吸附焓变表明,苯乙酸在AH树脂上的吸附是物理吸附和化学吸附共同作用的结果.对苯乙酸被3种树脂吸附的吸附焓变、自由能变、吸附熵变也作了计算,并对吸附行为作了合理的解释。 相似文献
10.
MQ silicone resins were prepared through hydrolytic condensation of ethyl polysilicate ortetraethoxysilane and hexamethyl disiloxane. The unit ratio of the MQ resins was determined by ~(29)Si-NMR.The relationship of the unit ratio of the product resins with that in the feed was studied. When the reactionwas catalyzed by aqueous hydrochloric acid, and the unit ratio of M to Q in the feed was more than 1, the unitratio of the product was usually lower than that of the feed. The MQ silicon with an unit ratio of M/Q>2could not be obtained. However, if the reaction was catalyzed by concentrated sulfuric acid and the reversehydrolysis process was employed, MQ silicone resin with very high M/Q ratio was successfully prepared. 相似文献
11.
用二甲基胺取代 烃基膦酸树脂对钆的吸附行为进行研究,试验结果表明,在pH4.90时,树脂对钆的静态饱和吸附容量为219mg·g-1(树脂);用2mol·L-1HCl可以定量洗脱;表观吸附速率常数k298=1.81×10-4s-1,测得吸附热力学参数分别为:ΔH=77.46kJ·mol-1,ΔG=-32.417kJ·mol-1,ΔS=368.69J·mol-1·K-1;等温吸附服从Frenndlich曲线;树脂功能基与Gd(Ⅲ)的配位比为2∶1;并用红外光谱探讨了树脂与钆的成键情况。 相似文献
12.
为克服在甲苯磺酸异构体定量分析结果中重复性和准确性差的问题,从多种色谱固定液中选出合适固定液,以正十十一烷作为内标物,优化了色谱条件,对气相色谱法研究甲苯磺酸乙酯异构体中的诸多影响因素进行了比较,确定了汽化室温度对于邻、间、对甲苯磺酸乙酯异构体准确测定的影响作用。 相似文献
13.
醇酸树脂热炼过程中分子量分布的研究 总被引:1,自引:0,他引:1
<正> 涂料工业中醇酸树脂基料分子量分布的研究,通常采用萃取分级法和沉淀分级法,近年来发展了高速凝胶色谱法。我们曾报道了高效GPC法测定醇酸树脂的分子量分布的方法。本文就醇酸树脂热炼过程产物作了物性表征和研究。 实验所测试样系取自5吨反应釜热炼生产中酯化过程各阶段和反应终点的产物。各品种醇酸树脂的配方见表1。 相似文献
14.
由于高聚物材料的应用日益广泛,对高聚物热稳定性问题的研究也有了相应的发展。近年来,在高聚物热裂解动力学方面出现了一系列新的研究方法,如等速升温热重分析法,差热分析法等。前者允许在一较宽的温度范围内观察热分解现象,计算裂解活化能。后者可以发现高聚物在加热过程中,体系的相变、异构化、氧化等现象。而利用不同等速升温条件下的差热分析法,使我们有可能对整个裂解过程中在一定温度范围内某个确定反应的动力学数据进行计算。然而仅有的一些工作大部分只涉及热塑性树脂。本工作利用等速升温条件下的热重分析法和差热分析法以及恒温下的失重法来研究固化 相似文献
15.
16.
17.
N-三羟甲基甲基氨基乙磺酸(TES)的胺基与异佛尔酮二异氰酸酯(IPDI)环上活性较高的NCO在低温15℃下发生选择性反应,生成AB3型单体.随后提高反应温度(70~90℃),使AB3型单体原位聚合,一锅法合成出含磺酸基超支化聚氨酯.随着聚合温度的提高,超支化聚氨酯的支化度、分子量及分子量分布系数变大.90℃时,聚合产物的Mn为22410,支化度达到0.87.以此含磺酸基超支化聚氨酯为基础制得的聚合物电解质膜具有良好的耐热性、机械强度,其锂盐室温(约25℃)的离子电导率为3.1×10-5S/cm,100℃达到1.4×10-3 S/cm. 相似文献
18.
Abstract This paper deals with the structure and chemistry of Nafion-H, the acidic form of Nafion, which is the trade name for a perfluorinated polymer manufactured by E. I. du Pont de Nemours & Co., Inc. Nafion-H and its salts are available from Dupont in both membrane and powder forms. Nafion composites with Teflon mesh (polytetrafluoroethylene) added to give increased mechanical strength are also available. In addition, sulfonated fluorocarbons modified with other chemically active polymers have been made by Dupont and by competing companies such as Ashai Chemical Industry Co., Ashai Glass Co., Tokuyama Soda Co., and Toya Soda Co. 相似文献
19.