多孔温敏凝胶的制备及性能测试

N-异丙基丙烯酰胺(NIPA)具有优良的温敏智能特性和记忆效应,目前已在药物缓释、物料分离、酶的固定、生物医学材料等领域得到广泛应用.本文以不同分子量的聚乙二醇(PEG)为致孔剂,在18℃下制备了多孔结构的共聚凝胶,并考察了聚乙二醇(PEG)分子量和用量对凝胶溶胀率的影响.研究表明,PEG的加入使凝胶形成多孔结构,多孔...     

反相色谱法测定PEG平均分子量

<正> 反相色谱广泛用于高聚物研究,也可用于低聚物平均分子量的测定。本文采用反相色谱法测定PEG(聚乙二醇)低聚物的平均分子量。PEG作固定相,非极性的正     

高效液相包谱法分离和测定非离子表面活性剂中游离聚乙二醇

本文采用反相高压液体色谱（RHPLC）法，以国产无定型微粒硅胶化学键合相YWG-C_(18)H_(37)为固定相，以90/10的甲醇-水作移动相，用示差折光检测器，对几种主要类型的非离子表面活性剂中的游离聚乙二醇（PEG）含量进行了很好的分离和定量。并提出检测器对不同分子量PEG的响应值有一较宽适应范围，不必预先测定PEG平均分子量的概念，大大简化了分析手续。方法最大相对标准偏差为7％，平均回收率为98.6％，一次色谱分离和定量所需时间小于20分钟。     

聚乙二醇单甲醚羧基衍生物的制备

以相对分子质量(简称分子量,下同)为1 200、2 000、5 000的聚乙二醇单甲醚(mPEG)为原料,采用琼斯试剂氧化法室温下制备羧基化的聚乙二醇单甲醚。产物结构经1HNMR和IR进行了确证。以羧基转化率为指标,探讨了反应物料最佳摩尔比为:n(Cr2O3)∶n(聚乙二醇单甲醚羟基)=2∶1,3种分子量产物的羧基转化率分别为99.6%,99.4%,98.0%。采用固液萃取法进行后处理,以产物外观颜色为指标,结果表明,固液萃取法中,先蒸除丙酮再加入碳酸氢钠中和的处理顺序获得的产物的颜色为白色,产物纯度高。以产物产率为指标,以分子量为1 000,1 200,2 000,5 000的聚乙二醇单甲醚(mPEG)及分子量为800的聚乙二醇(PEG)为原料制备羧基化衍生物,结果表明,该法适合于分子量大于2 000的聚乙二醇及分子量大于1 000的聚乙二醇单甲醚的羧基衍生物的制备,5种分子量产物的产率分别为88.2%,93.5%,98.0%,98.2%,39.1%。     

双水相体系萃取木瓜蛋白酶的研究

采用聚乙二醇(PEG)/(NH4)2SO4双水相体系对木瓜蛋白酶进行萃取分离,研究了PEG相对分子量、PEG质量分数、(NH4)2SO4质量分数和pH值对木瓜蛋白酶分配系数及酶活力回收率的影响.结果表明,最佳萃取条件为:PEG4000质量分数6%、(NH4)2SO4质量分数18%、pH值6.0,在此条件下,木瓜蛋白酶的...     

双水相体系萃取精氨酸脱亚胺酶

报道了利用聚乙二醇/硫酸铵双水相体系从自溶NJ402菌粗提酶液中分离纯化精氨酸脱亚氨酶(ADI)的研究结果,为精氨酸脱亚氨酶的分离纯化提供了一种方法。在双水相体系中采用聚乙二醇(PEG)与(NH4)2SO4为组成成分,考察了聚乙二醇(PEG)平均相对分子质量、PEG质量分数、(NH4)2SO4质量分数、pH及NaCl质量分数对精氨酸脱亚氨酶分离纯化效果的影响。最佳双水相体系萃取条件为:聚乙二醇(PEG)平均相对分子质量为1 000,w(PEG1000)=15%,w[(NH4)2SO4]=20%,pH=6.5,室温下从自溶NJ402菌粗提酶液中分离纯化精氨酸脱亚氨酶,纯化倍数达到2.35倍,萃取率达91.1%。     

二苯甲酮类聚乙二醇基水溶型紫外线吸收剂的合成与表征

将2,4-二羟基二苯甲酮(UV-0)与氯乙酰氯反应合成2-羟基-4-氯乙酸酯基二苯甲酮(2H4CBP)中间体,然后利用氯乙酸酯基中活泼α-氯与不同分子量的聚乙二醇钠反应,合成了一系列聚乙二醇基水溶型紫外线吸收剂.采用红外光谱(FT-IR)、紫外光谱(UV)、核磁(1H-NMR)等手段对产物进行了结构表征.考察了不同平均分子量的聚乙二醇(PEGC(MW))对产物水溶解性能的影响,通过分光光度计测定计算了产物的紫外吸收效果残存率并考察了产物的光稳定性.结果表明当 PEG 平均分子量(MW)达到 1540 时,产物水溶性最好,溶解度为 6.87;产物在 243 nm、290 nm 和 322 nm处有强紫外吸收,并显示出较好的光稳定性;产物 PEG2000-g-(UV-0)2和PEG1540-g-(UV-0)2 在 290 nm处的摩尔消光系数分别为17899.7 L·mol-1·cm-1和17073.6 L·mol-1·cm-1.     

聚乙二醇对聚酰亚胺泡沫的结构及热性能的影响

采用聚(酯-铵)盐(PEAS)前体粉末发泡法制备聚酰亚胺泡沫,分别考察了分子量为400,1000和2000的聚乙二醇(PEG)对PEAS前体及聚酰亚胺泡沫的影响。结果表明,PEG的加入使聚酰亚胺泡沫的平均孔径由0.35 mm增加到0.50 mm以上,不同分子量的PEG没有导致聚酰亚胺泡沫的平均孔径产生显著的差别。红外光谱表明,PEG的加入对聚酰亚胺泡沫及其前体的化学结构没有明显改变。由PEG/PEAS前体制备的聚酰亚胺泡沫在350℃仍保持较好的热稳定性。     

不同分子量聚乙二醇单修饰重组人干扰素a-2a

利用N-羟基琥珀酰亚胺活化制备不同分子量的聚乙二醇修饰剂(NHS-mPEG，分子量5000, 10000, 20000)，考察三者水解动力学性质的差异，结合正交实验确定了不同分子量修饰剂制备单条PEG链修饰重组人干扰素a-2a(rhIFN-a-2a)的最佳反应条件，用离子交换法对产物进行分离纯化. 研究了不同分子量聚乙二醇干扰素结合物的体外活性，比较其蛋白收率. 实验结果表明，修饰剂分子量增大，应选择蛋白与修饰剂的反应活性高的修饰反应条件，体外活性虽然降低，但同时单修饰聚乙二醇干扰素结合物收率更高，产品质量更易控制.     

应用技术

<正> 氢键型固定液——聚乙二醇聚乙二醇又可称为聚环氧烷,是应用最广泛的固定液之一,也是优选固定液之一。上海试剂一厂生产的PEG 系列相当于美国Union Carbide Co.同分子量的Carbowax。以下是按不同平均分子量而分类的上试PEG 产品。各种聚乙二醇色谱固定液     

Fast Gel Permeation Chromatography Using Large Gel Particles

Abstract

In two previous papers (1,2), we reported the effect of several operational parameters on separations by gel permeation chromatography (GPC). These studies included the effects of (a) solvent flow rate, (b) sample concentration, (c) sample molecular weight, (d) particle size, and (e) operating temperature. In this present study, we used extremely large particles (200–300 μ diameter) at flow rates up to 10 ml/min. This was done to magnify solute diffusion effects in hope of gaining a better understanding of the permeation process. By using the relatively large particles, interstitial spaces between particles will be wider and the gel pores deeper than with particles normally used (less than 75 μ) in GPC.     

刺激应答性高分子凝胶

刺激应答高分子凝胶具有在温度、PH、溶剂组成改变或在外加电场、光照刺激下,体积发生剧烈变化的应答功能。可作为一种新型的智能材料。     

Gel Filtration Chromatography

Abstract

The technique of gel filtration chromatography is described, with a guide to relevant literature on methods, theory, and applications, especially the use of GFC in analysis of molecular interactions, both macromolecular and small molecule-macromolecule aggregation.     

Gel in polyethylene

A quantitative test for the presence of gel (insoluble polymer) in polyethylene is described. A number of experiments were performed by using the test and on the polymers separated by the test. It is concluded that gel is crosslinked polyethylene in the form of discrete particles of significant size, the large ones, probably weighing up to at least 10 mg. Some crosslinks are broken by treatment with solvents above 200°C., and much of the gel is thus rendered permanently soluble. Gel is also insoluble in the reaction medium in which it is produced. Thus, even if the ethylene–polyethylene phase relationships would predict a homogeneous reaction, the reaction must be hetero-geneous if gel is present. Therefore, kinetic treatments of ethylene polymerization which do not consider phase separation when gel is found in the reaction product are oversimplified.     

Active Polymer Gel Actuators

Many kinds of stimuli-responsive polymer and gels have been developed and applied to biomimetic actuators or artificial muscles. Electroactive polymers that change shape when stimulated electrically seem to be particularly promising. In all cases, however, the mechanical motion is driven by external stimuli, for example, reversing the direction of electric field. On the other hand, many living organisms can generate an autonomous motion without external driving stimuli like self-beating of heart muscles. Here we show a novel biomimetic gel actuator that can walk spontaneously with a worm-like motion without switching of external stimuli. The self-oscillating motion is produced by dissipating chemical energy of oscillating reaction. Although the gel is completely composed of synthetic polymer, it shows autonomous motion as if it were alive.     

Gel formation in ionomers

A theoretical study of the phase diagram of ionomer solutions in water is presented. These systems show two phase transitions: a demixing transition and a gelation. The demixing transition is studied using Flory's theory of polymer solutions. The gelation concentration always scales as the overlap concentration $\text{c1}$; the dependence of the phase boundaries on temperature and on the fraction f of metallic groups along the chain is studied. At high temperatures, in a good solvent regime, c_gel is proportional to $\text{f}{}^{\mathrm{<mtext>-8</mtext><mtext>5</mtext>}}$; at lower temperatures c_gel is proportional to f^?1.     

Isotachophoresis on Polyacrylamide Gel

Abstract

Isotachophoresis, using Ampholine spacer ions, was applied to the fractionation of two multicomponent protein systems (serum and a urinary preparation tract with Hunter Factor activity) using polyacrylamide gel as a supporting medium. These studies were designed to determine whether isotachophoresis could provide higher load capacity than obtained in conventional electrophoresis or isoelectric focusing on polyacrylamide gel without loss of resolution. The effect of the Ampholine pI range, the relative and absolute concentrations of protein sample and Ampholine, of the ionic strength of the gel buffer, and of the stacking limits obtained in various gel buffers was investigated. It was found that Ampholine components can act as spacers, giving rise to bands in what otherwise would be a continuum of stacked protein zones. Loads greater by 1 to 2 orders of magnitude than in conventional polyacrylamide gel electrophoresis were applicable. The resotion obtained was greatly inferior to that in PAGE, suggesting that Ampholine does not provide a sufficient distribution of constituent mobilities under the employed conditions. Isotachophoresis was applied at the preparative scale in two-stage fractionations designed to resolve multicomponent systems (serum).     

纤维蛋白凝胶的研制

以血浆蛋白冷沉淀为原料制备粘合蛋白，富含纤维蛋白原、调理素蛋白、凝血因子XⅢ，其可凝固蛋白大于75mg／ml，蛋白含量大于100mg／ml；主要以CohnⅢ为原料．采用组织凝血活酶和Ca激活制备高效价凝血酶，成品放价达400～500u／ml；以牛肺为原料，经特异沉淀和亲和层析制备抑肽酶，成品效价达10000UKIV／ml以上．以粘合蛋白、凝血酶、抑肽酶组成的纤维蛋白凝胶，其质量基本达到国际同类产品先进水平。动物试验和初步临床观察表明．凝胶具有止血、粘合等功能，尤其是在常规方法难以处理的部位更加有效。     

聚丙烯酰胺凝胶体系

聚丙烯酰胺凝胶体系是一种油田常用的堵水调剖剂.铬交联剂形成的凝胶体系粘度为6000～7000 mPa·s,铝凝胶体系成胶时间为3～15 d可调,强度为100～1500 mPa·s,有机酚醛交联体系粘度为500～1500 mPa·s.本文对聚丙烯酰胺凝胶体系的研究方向作了展望.     

Gel filtration of surfactants

A simulation technique was developed for analyzing the gel filtration chromatography of surfactants. Theoretical elution curves obtained by this technique were compared with the experimental curves for the following five systems: an ionic or a nonionic surfactant of a single component, an ionic surfactant in the presence of an electrolyte, a mixture of two nonionic surfactants, a mixture of two ionic surfactants, and a mixture of an ionic and a nonionic surfactant. In the first four systems, good agreement was found between the theoretical and experimental elution curves. A possible explanation for the disagreement in the last system is presented.