聚乙烯与丙烯酸的溶液接枝聚合

以过氧化苯甲酰为引发剂，二甲苯为溶剂，进行了丙烯酸与低密度聚乙烯的溶液接枝聚合，研究了ＢＰＯ用量、溶液浓度以及丙烯酸用量对接枝率的影响。聚乙烯接枝了丙烯酸后与铝的粘结强度显著增大，当接枝率为７．２％时，剥离强度由未接枝时的１９３Ｎ／ｍ，提高到９８４Ｎ／ｍ。     

高锰酸钾—硫脲体系引发丙烯酸接枝共聚尼龙的研究

研究了以高锰酸钾和硫脲组成的氧化还原引发体系,在水介质中,引发丙烯酸接枝共聚尼龙的共聚反应。考察了丙烯酸浓度、引发剂浓度及温度等因素对接枝共聚反应的影响。红外光谱分析和Ｘ射线衍射图谱证明了接枝反应的存在及对聚合物结晶度的影响。     

Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and rDE and rNaAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.     

丙烯酸-丙烯酰胺共聚物研究进展

丙烯酸,丙烯酰胺的均聚物和共聚物用途广泛,是一种非常重要的高分子化合物。本文主要介绍此类高分子的有关性质,如流性能,降解性能等,研究进展,以及主要制备方法：水解法、水溶液聚合法,反相乳液滞法和反相悬浮聚合法等。     

二乙基二烯丙基氯化铵与丙烯酰胺、丙烯酸共聚竞聚率

二乙基二烯丙基氯化铵;丙烯酰胺;丙烯酸;共聚合;竞聚率     

The Preparation and Properties of Acrylic and Methacrylic Acid Grafted Cellulose Prepared by Ceric Ion Initiation. Part I. Preparation of the Grafted Cellulose

The ceric ion method has been used to graft acrylic acid directly onto cellulose with a minimum amount of homopolymer. The method utilizes the pretreatment of the cellulose with ceric ammonium nitrate followed by washing out any excess of the catalyst. Oxygen can be present with the pretreatment step, but must be excluded during the grafting reaction itself. The process, which is entirely aqueous in nature, would appear to be quite practical on a large scale. Wet strengthened papers which are essential for the use of the grafted products as ion-exchange media can also be grafted but with adequate but lower yields than with the untreated paper. Apart from ion exchange, the products are of considerable potential value as water sorbing agents. Methacrylic acid gave lower grafting yields than acrylic acid, but these were much improved at higher temperatures.     

丙烯酸与丙烯酰胺共聚制备高吸水性树脂

采用溶液聚合法,以N,N’-亚甲基双丙烯酰胺（NMBA）为交联剂,过硫酸钾（KPS）为引发剂合成了高吸水性树脂聚（丙烯酸-丙烯酰胺）（P（AA—AM））,研究了单体配比、丙烯酸中和度、引发剂及交联剂用量、反应温度对树脂在去离子水和0．9％盐水中吸水率的影响．最佳条件下制备的树脂在去离子水中吸水率为750g·g^-1,在0．9％盐水中吸水率为85g·g^-1．     

乙丙共聚物接枝马来酸酐反应机理的模拟研究

接枝反应;角鲨烷;乙丙共聚物接枝马来酸酐反应机理的模拟研究     

Superswelling of Hydrogels Based on the Copolymer of Acrylamide and Methacrylic Acid

Weakly crosslinked hydrogels of copolymers of acrylamide and methacrylic acid are synthesized by radical polymerization in aqueous solution in a wide range of comonomer ratios. It is found that gels containing 20–40 mol % methacrylic acid are characterized by superswelling that exceeds the degree of swelling of homopolymer hydrogels by tens of times. The observed degree of swelling reaches 830, corresponding to an almost completely stretched conformation of subchains between network junctions. For dried hydrogel samples, the equilibrium degree of swelling is also maximal in the mentioned composition range; however, its maximum value is lower than the equilibrium degree of swelling for the initial samples. The possible reason behind the superswelling of hydrogels containing 20–40% units of methacrylic acid is an increase in ionization of network subchains. This hypothesis is proved by an increased sensibility of hydrogels of this composition to a change in the pH of a medium and the lowest values of the effective acidity constant determined by potentiometric titration for methacrylic acid units. The values of partial heat capacity of a gel polymer network are determined by calorimetry. These values are significantly higher than the heat capacities typical of vinyl polymers. This is evidence that the hydrophobic type of hydration predominates in the copolymers of acrylamide and methacrylic acid. The partial heat capacity reaches its maximum within the copolymer composition range corresponding to superswelling.     

水溶液中单电子转移活性自由基聚合法制备新型阳离子共聚丙烯酰胺/丙烯酸酯

以咪唑、丙烯腈和溴辛烷等为原料,合成了新型阳离子型可聚合离子液体表面活性剂单体：氯化-1-正辛基-3-（4-丙烯酸丁酯基）咪唑（PMOIH8）。 以2-氯丙酰胺为引发剂,Cu0粉/三-（2-二甲氨基乙基）-Me-6-TREN为催化体系,采用单电子转移活性自由基聚合法对丙烯酰胺（AM）、PMOIH8进行了二元共聚合反应,合成了一种新型阳离子共聚丙烯酰胺/丙烯酸酯P（AM/PMOIH）。 FT-IR、MS和1H NMR分析表明,所得聚合物为目标产物,采用GPC测得聚合物的相对分子质量为2×103~14×103,相对分子质量分布Mw/Mn在1.21~1.75之间。 考察了催化剂、引发剂等因素对聚合的影响。 结果表明,降低催化剂用量,聚合反应速率变慢,链增长速率常数kappp由0.0168 min-1降低至0.0065 min-1,Mw/Mn由1.25~1.71增加至1.32~1.75,引发效率Ieff=90.24%;增加引发剂用量,Mw/Mn由1.25~1.71减小至1.21~1.68,kappp由0.0168 min-1增加至0.0201 min-1,Ieff增加至93.17%。     

汞代N-乙烯基咔唑-丙烯酸共聚物的合成与研究

制备线型和网状N-乙烯基咔唑-丙烯酸甲酯共聚物后,用三氟乙酸汞分别在四氢呋喃(THF)和二氯甲烷中进行汞化反应,得到相应的线型和网状汞代咔唑共聚物。这些共聚物经THF溶解或溶胀后,用氢氧化钠水溶液水解,得到相应的水溶性线型高分子和吸水性网状高分子,憎水性汞代咔唑共聚物在THF中由I₂取代汞;亲水性汞代咔唑共聚物在水溶液中由KI₃取代汞。汞代咔唑高分子链在不同溶剂中可以产生不同的形态变化。     

丙烯酸-丙烯酰胺原位插层共聚制备高吸水性蒙脱土纳米复合材料的研究

在钠基蒙脱土(MMT)悬浮液中，采用丙烯酸(AA)和丙烯酰胺(AM)两种单体进行原位插层共聚，得到高吸水性纳米复合材料。研究了引发剂和交联剂对材料吸水率的影响。X射线衍射(XRD)结果表明：复合材料中蒙脱土片层001面的层问距随mMMT／mM的减小而增大，当mMMT／mM≤1／3时，复合材料中的蒙脱土已完全剥离。DSC测试表明，在蒙脱土含量较低时，其玻璃化转变温度Tg随MMT含量的升高逐渐提高。吸水速率和保水能力测试结果表明，材料吸收去离子水能力达610g／gR，吸收盐水(wNaCl=0．009)能力达89g／gR。蒙脱土片层的引入。在一定程度上提高了材料的初期吸水速率和加压下的保水能力。     

A Nonhydrolyzable-Water Soluble Crosslinker: Tetrallylpiperazinium Dichloride and its Copolymers with Acrylic Acid and Acrylamide

Abstract

A versatile crosslinking agent, tetraallyl piperazinium dichloride (TAP) has been prepared and demonstrated to be useful in copolymerization with water soluble monomers such as acrylic acid and acrylamide. Although the crosslinker itself does not readily homopolymerize in water, it forms transparent rigid hydrogels within a reasonable period of time when copolymerized with acrylic acid. Being nonhydrolysable, the crosslinker presented is superior to other common water soluble crosslinking agents such as methylene or ethylene bis(acrylamides). Since this crosslinker has a low toxicity, it may be used for bioapplications such as gel electrophoresis etc.     

Dynamics of Water Absorption by the Copolymer of Dimethyldiallylammonium Chloride and Acrylic Acid

Russian Journal of General Chemistry - The swelling of the cyclochain copolymer of N,N-dimethyl-N,N-diallylammonium chloride with acrylic acid in water was studied. For the first time, an increase...     

Immobilization of Heparin and Highly-Sulphated Hyaluronic Acid onto Plasma-Treated Polyethylene

Heparin and highly-sulphated hyaluronic acid have been successfully immobilized onto plasma-processed polyethylene via a diamine polyethyleneglycol (PEG) spacer molecule. Two different plasma-processes have been utilized, i.e. a treatment and a deposition process, for providing polyethylene surface with the COOH groups necessary for the immobilization reactions. XPS integrated with derivatization procedures, ATR-FTIR and Water Contact Angle measurements have been carried out for characterizing each modification step: 1) the plasma-process, 2) the immobilization of the spacer molecule and 3) the immobilization of the biomolecules. The thrombin time of the modified surfaces has been measured, and their platelet activation characteristics evaluated. The results indicate a certain nonthrombogenic character of the biomolecule-immobilized polyethylene samples.     

悬浮法合成聚丙烯接枝丙烯酸

用过氧化二苯甲酰作引发剂以水相悬浮法合成聚丙烯接枝丙烯酸。通过反应条件、组分等因素对PP的接枝率和接枝效率的影响研究,确定较佳配比工艺条件：溶用莳8-0min;反应温度90℃;反应时间90min;在氮气气氛中,丙烯酸7％;过氧化二苯甲酰3．3％;二甲苯25％;水和聚丙烯的重量比为3：1;若加入适量催化剂（1－1．7％0异氰尿酸三烯丙酯能显著提高接枝率。用此PP－g-AA作CaCO3、PP/PA6和合物的相容剂,材料的力学性能有很大的提高。     

水溶性荧光高分子乙烯基咔唑－丙烯酸共聚物的合成及荧光测试

用偶氮二异丁腈作引发剂，使Ｎ－乙烯基咔唑和丙烯酸甲酯在苯中共聚合，该共聚物在四氢呋喃中用氢氧化钠水溶液水解，得到水溶性乙烯基咔唑－丙烯酸共聚物。该共聚物的水溶液在３７３ｎｍ处产生较强的荧光，其荧光强度随溶液ｐＨ值增大而增强，在该高分子水溶液中，加入少量阳离子表面活性剂，其量子产率可提高７倍，微量重金属离子（Ｈｇ（２＋））对荧光有一定的熄灭作用。荧光强度（ｌｏｇＩ０／Ｉ）与Ｈｇ（２＋）的浓度呈线性关系。