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1.
使用化学共混法和机械共混法制备了三嵌段苯乙烯-丁二烯-苯乙烯共聚物(SBS)/聚(苯乙烯-甲基丙烯酸盐)热塑性互穿聚合物网络(IPN).用透射电镜和动态力学方法研究了它们的形态和玻璃化转变行为.实验结果显示出,由母体形成IPN提高了体系的相容性,且化学共混方法明显好于机械共混法.IPN样品均呈微观相分离形态,具有两个分属于聚丁二烯相和聚(苯乙烯-甲基丙烯酸盐)相的玻璃化转变温度.通过Budiansky方程和Kerner方程对动态模量数据的分析表明,IPN样品具有两相连续性,且随SBS(聚合物Ⅰ)组分含量的增加,聚(苯乙烯-甲基丙烯酸)(聚合物Ⅱ)的连续程度降低  相似文献   

2.
小角X-光散射方法对苯乙烯-丁二烯-苯乙烯三嵌段共聚物/聚(苯乙烯-甲基丙烯酸盐)热塑性IPN共混体系相区尺寸的研究韦雨春,袁惠根,潘祖仁(浙江大学化工系杭州310027)关键词热塑性互穿聚合物网络,小角X-光散射,透射电镜随着IPN研究的不断深人,...  相似文献   

3.
用DSC法研究苯乙烯-丙烯嵌段共聚物(iPS-b-iPP)的等温结晶动力学,结果表明,在所选择的结晶温度(127-132℃)范围内,共聚物很好地符合Avrami动力学方程;共聚物结晶温度,结晶速率,结晶成和生长方式都与共聚物结构和组成比在关,随着嵌段共的中iPS段含量的增加,结晶速率和Avrami指数(n)明显降低。  相似文献   

4.
报道用稀土化合物改性的钛系截体催化剂(SN催化剂)进行苯乙烯和丙烯顺序嵌段共聚合(Sequentialblockcopolymerization)的研究,通过对初生嵌段共聚产物进行溶剂萃取与分级,并用13C-NMR、WAXD.DSC,DMA和电子显微镜进行表征,推断共聚物为具有等规聚苯乙烯链和等规聚丙烯链段的A-B型二嵌段共聚物,且各段均能结晶。发现嵌段共聚物比相应的均聚物具有较好的综合力学性能和热性能,而且对iPS/iPP共混具有良好的增容作用。  相似文献   

5.
丙烯酸丁酯-苯乙烯-丙烯腈共聚物的结构与力学性能张会轩,韩业,张会良,冯之榴(吉林工学院化工系长春130012)(中国科学院长春应用化学研究所长春)关键词ASA,乳液聚合,粒子,力学性能丙烯酸丁酯-苯乙烯-丙烯腈共聚物(ASA)是两相结构,聚丙烯酸丁...  相似文献   

6.
通过测定表面动态接触角研究了两亲性的苯乙烯/甲基丙烯酸嵌段共聚物(PS-b-PMAA)和苯乙烯/甲基丙烯酸(β-羟丙酯)嵌段共聚物(PA-b-PHPMA)的表面动态行为及温度、嵌段长度比等因素对其值的影响,讨论了聚合物表面当接触介质改变时链段或基团的再取向行为和表面性质。  相似文献   

7.
用二苯甲烷钾为引发剂,阴离子聚合法合成了苯乙烯(St)-环氧乙烷(EO)嵌段共聚物,并用FTIR,^1H-NMR,SEC,WAXD和动态粘弹谱对共聚物进行了表征。结果表明所得聚合物为分子量可控,窄分布的两嵌段共聚物。  相似文献   

8.
用稀土化合物改性的钛系载体催化剂(SN催化剂)进行苯乙烯和丙烯顺序嵌段共聚合(Sequentialblockcopolymerization)的研究.考察了苯乙烯预聚时间、单体比、外加给电子体(EB)、烷基铝浓度、催化剂浓度和聚合温度等条件对共聚合的影响.发现外加酯(EB)降低了共聚合反应催化活性,在EB/Ti摩尔比为5范围内,外酯有助于提高嵌段共聚物(iPS—b—iPP)中PS段和PP段的等规度及增加苯乙烯链节含量.SN型催化剂对苯乙烯一丙烯嵌段共聚合有较高的催化活性,催化效率在100g聚合物/g-Ti以上.共聚物通过溶剂革取分级除去均聚物后,所得嵌段共聚物中苯乙烯链节含量可在15~85mol%之间调节.其结构表征续见第II报.  相似文献   

9.
通过测定表面动态接触角研究了两亲性的苯乙烯/甲基丙烯酸嵌段共聚物(PS b PMAA)和苯乙烯/甲基丙烯酸(β 羟丙酯)嵌段共聚物(PS b PHPMA)的表面动态行为及温度、嵌段长度比等因素对其值的影响,讨论了聚合物表面当接触介质改变时链段或基团的再取向行为和表面性质  相似文献   

10.
苯乙烯-异戊二烯/丁二烯-苯乙烯嵌段共聚物的结构如下:  相似文献   

11.
pH and ionic sensitive interpenetrating polymer network (IPN) complex films based on chitosan (CS) and carboxymethyl chitosan (CM-CS) were prepared by using glutaraldehyde as crosslinking agent. Its structure was characterized by FT-IR, which indicated that the IPN was formed. The films were studied by swelling, weight loss with time, and release of coenzyme A (CoA). It was found that the IPN films were sensitive to pH and ionic strength of the medium. The cumulative release rate of CoA decreased with CoA loading content, ionic strength or crosslinking agent increasing. The composition of the IPN films and pH of release medium also had significant effect on the release of CoA. The differences in the rates and amounts of released CoA may be attributed to the swelling behavior, the degradation of films, and interaction between drug molecule and polymer matrix. These results suggested CS/CM-CS IPN films could be used as drug delivery carrier.  相似文献   

12.
壳聚糖·聚丙烯酸配合物半互穿聚合物网络膜及其对pH和离子的刺激响应李文俊王汉夫卢玉华汪志亮钟伟(复旦大学高分子科学系聚合物分子工程开放实验室上海200433)关键词高分子间配合物,互穿聚合物网络(IPN),水凝胶,壳聚糖,刺激响应敏感性水凝胶是一种...  相似文献   

13.
 本文用SAXS(Small Angle X-ray Scattering)方法对全氟磺酸树脂中空纤维膜中的离子簇结构进行了研究.在散射角2θ=2°左右,出现由离子簇产生的散射峰;并就离子交换容量、不同阳离子形式、含水量及不同拉伸等对离子簇散射峰位的影响进行了研究讨论.并计算了有关离子簇半径和每个离子簇中的离子数目.  相似文献   

14.
A novel adsorbent Pb(II)-imprinted interpenetrating polymer network (IPN) of epoxy resin-triethylenetetramine and lead methacrylate-acrylamide-1,4-butanedioldiacrylate (BDDA) was synthesized by the metal ionic imprinted polymer (MIIP) technique. The IPN was prepared by in situ sequential polymerization, and the coordination interaction of Pb(II) and functional groups of the IPN adsorbent was discussed using FT-IR spectra. The characters of the IPN were investigated by a series of experiments. The experimental results show that trace Pb(II) ions can be quantitatively preconcentrated at pH 4.0 with recoveries >95%. The maximum static adsorption capacity of the ion-imprinted adsorbent was 138.6?mg?g?1. The imprinted IPN has a higher adsorption capacity and selectivity towards Pb(II). Moreover, the Pb(II)-imprinted IPN shows superior reusability and stability. The precision (R.S.D.) for 11 replicate adsorbent extractions of 20?ng?mL?1 Pb(II) was 2.9%. The accuracy of the proposed procedure was verified by analysing three standard reference materials. The prepared ion-imprinted IPN adsorbent was applied to three natural samples and also yielded satisfactory results. That is to say, the Pb(II)-imprinted IPN is suitable for environmental Pb(II) ionic selective removal as an SPE adsorbent.  相似文献   

15.
Semi‐interpenetrating polymer networks (semi‐IPNs) composed of chitosan and polyacrylamide (PAAm) hydrogels have been prepared, and the effect of changing pH, temperature, ionic concentration, and applied electric fields on the swelling of the hydrogels was investigated. The swelling kinetics increased rapidly, reaching equilibrium within 60 min. The semi‐IPN hydrogels exhibited a relatively high swelling ratios of 385%–569% at T=25°C. The swelling ratio increased with decreasing pH below pH=7 due to the dissociation of ionic bonds. The swelling ratio of the semi‐IPN hydrogels was pH, ionic concentration, temperature, and electric field dependent. Differential scanning calorimetry (DSC) was used to determine the volume of free water in the semi‐IPN hydrogels, which was found to increase with increasing PAAm content.  相似文献   

16.
采用分步法用电子加速器辐射合成了聚丙烯酰胺(PAAm)/聚异丙基丙烯酰胺(PNIPAAm)互穿网络水凝胶,并考察了温度、pH值、离子强度对其溶胀性能的影响.研究表明:互穿水凝胶具有温度敏感性,且其体积相变与互穿网络中PAAm和PNIPAAm含量有关,随着网络中PAAm含量的增加水凝胶的体积相变趋于平缓,可以通过改变PAAm和PNIPAAm的组成比来控制水凝胶的体积相变行为.此外,互穿水凝胶还具有pH敏感性和一定的抗盐性.  相似文献   

17.
Hydrophilic PU and hydrophobic PS IPN membranes were prepared and the effect of the synthesis pressure on the pervaporation characteristics of ethanol water mixture was evaluated. Cationic/anionic IPN membranes were prepared from the cationic PU and the anionic acrylic copolymer, and the effects of the composition and the ionic concentration on the permeation characteristics were analyzed. The gas (oxygen and nitrogen) transport of the IPN membranes of PU/PS were also examined. The effect of synthesis temperature and composition of the IPN membranes were analyzed.  相似文献   

18.
本工作合成了磺化的3,4-聚异戊二烯及其离子聚合体,IR和NMR谱图证明对3,4-聚异戊二烯的磺化反应是成功的,并且磺酸基团主要与3,4-链节的侧基双键发生反应。WAXD对磺化3,4-聚异戊二烯及其离聚体的研究表明,磺化度的增加使离聚体的结晶能力降低,SAXS结果表明,在离子含量为3.29mol%的离聚体中,未观察到离子簇聚集,只观察到多重离子对的散射。  相似文献   

19.
红外光谱法研究离聚体中离子聚集状态   总被引:3,自引:0,他引:3  
红外光谱法研究离聚体中离子聚集状态冯克,高洪涛,李卓美,阎荣江(中山大学高分子研究所,广州,510275)(中国科学院长春应用化学研究所)关键词离聚体,红外光谱,离子聚集离聚体是指含有15mol%以下离子基团的聚合物,依离子含量高低,离子聚集状态分为...  相似文献   

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