聚丙烯酸钠吸水性树脂的抗电解质性能

丙烯酰胺;聚丙烯酸钠吸水性树脂的抗电解质性能     

聚丙烯酸钠和丝素蛋白自膨胀水凝胶的制备及其释药性能

通过自由基聚合的方法合成制备了自膨胀PAAS-SF semi-IPN水凝胶(聚丙烯酸钠-丝素半互穿网络水凝胶),并进一步探讨其作为微创治疗中组织植入物的潜能.主要研究了SF(丝素蛋白)和AA(丙烯酸)的重量比对PAAS-SFsemi-IPN水凝胶的结构、膨胀性以及力学性能的影响.此外,我们还研究了抗生素药物阿莫西林(AMO)在PAAS-SFsemi-IPN水凝胶中的包载与释放性能.结果表明,随着水凝胶中SF含量的增加,膨胀率增大,压缩强度减小,药物释放速率加快,且PAAS-SF20 semi-IPN水凝胶在120 h内能释放(83.4±0.9)%的药物.所开发的自膨胀PAAS-SFsemi-IPN水凝胶具有高膨胀率和良好的药物释放能力,将在药物输送或其它植入材料领域有良好的应用前景.     

低分子量聚丙烯酸钠的合成

低分子量聚丙烯酸及其钠盐广泛应用于造纸工业 ,随着高浓度涂布机的引进和铜板纸生产的发展 ,对分散剂的要求越来越大 ,因低分子量聚丙烯酸钠具有提高颜料的细度、分散体系的稳定性 ,提高纸张的柔软性、强度、光泽、白度等优点 ,所以低分子量丙烯酸在造纸工业上越来越受到重视。低分子量聚丙烯酸钠可用不同的方法合成[1,2 ] ,但都是在比较高的温度进行 ,并且要蒸馏回收大量的链转移剂 ,操作费时、耗能。本实验在较低温度下以氧化 还原催化剂直接合成了低分子量聚丙烯酸钠 ,经造纸厂实际应用试验证明 ,该分散剂可单独或与无机磷酸盐分散剂复…     

亚硫酸氢钠作链转移剂合成低分子量聚丙烯酸钠

采用水溶液聚合法,以K2S2O8-NaHSO3氧化还原体系为引发剂、NaHSO3为链转移剂,合成了低分子量聚丙烯酸钠.对实验条件进行了优化,结果表明:反应温度70℃,单体丙烯酸质量分数为20%~30%,NaHSO3与K2S2O8质量比为10∶1~14∶1,反应时间5h,可获得分子量为2000~4000的聚丙烯酸钠.     

碳纳米管复合聚丙烯酸钠的制备及吸水性能

以过硫酸铵(APS)为引发剂,N,N′-亚甲基双丙烯酰胺(MBA)为交联剂,采用水溶液聚合法制备了碳纳米管/聚丙烯酸钠高吸水树脂。系统考察了碳纳米管质量分数、引发剂、交联剂和聚合温度对树脂吸水性能的影响。结果表明,以单体丙烯酸质量为基准,当交联剂,引发剂和碳纳米管质量分数分别为0.04%、0.3%和0.3%,聚合温度75℃时,所合成树脂的吸水性能最佳。添加碳纳米管后树脂表面粗糙和形成孔结构导致了其吸水性能的变化,使得碳纳米管/聚丙烯酸钠的吸水量和吸水速率明显提高,其吸去离子水和生理盐水能力分别达到1423和104g/g。该树脂重复吸水5次后,其吸水能力为1081.5g/g,达到最大吸水倍数的76.0%。     

反相乳液聚合法合成高分子量聚丙烯酸钠

以丙烯酰氧基Span-80为乳化剂,采用反相乳液聚合法合成了高分子量聚丙烯酸钠.研究了乳化剂和中和度对聚合体系稳定性的影响,以及(NH4)2S2O8—甲基丙烯酸-N、N-二甲氨基乙酯(DMAEMA)—NaHSO3引发剂和单体浓度对聚合物分子量的影响.结果表明,最佳的实验条件:中和度为90%;乳化剂用量为3%(油相);引发剂占单体的质量分数分别为(NH4)2S2O80.06%、DMAEMA0.04%、NaHSO30.02%;单体在水相的质量分数为40%(水相).在最佳实验条件下,合成聚合物分子量超过2.6×107,且溶解性能优于溶液聚合所得产品.     

聚丙烯酸钠水凝胶基材退热贴的制备及其性能

制备了以聚丙烯酸钠为基材的高分子水凝胶退热贴。退热贴的含水率为56%~60%。对钢板和人造革的剥离力分别为26.6 g/cm和14.8 g/cm,粘附力达到日本产退热贴的水平。动物试验证明自制退热贴对内毒素致家兔体温升高有退热作用,使用后2~2.5h的退热效果较明显,5 h后,家兔体温基本恢复正常。初步临床实验也证明自制退热贴具有良好的退热效果,有效时间为4~6 h。     

火焰原子吸收法测定氧化铝中的钠

提出了用火焰原子吸收法测定氧化铝中钠的方法。样品在铂坩埚中用Ｌｉ２ＣＯ３－Ｈ３ＢＯ３于１０００℃下熔融２０ ｍ ｉｎ,后加硝酸（１＋ １） 使熔融物完全溶解;在硝酸介质中,加入铯盐作为消电离剂,可消除基体及其它共存元素的干扰。可测定Ａｌ２Ｏ３中质量分数为０．０１％ ～１．５０％ 范围内的Ｎａ２Ｏ,相对标准偏差＜３％ （ｎ＝ １１）,加标回收率为９８％ ～１０２％ 。     

辐射合成聚丙烯酰胺,聚丙烯酸钠及其共聚物水凝胶微观结构…

用＾６０Ｃｏ－γ射线辐射合成了低交联度的聚丙烯酰胺、聚丙烯酸钠及丙烯酰胺－丙烯酸钠共聚物水凝胶，用扫描电子显微镜研究了水凝胶经过丙酮脱水的干态试样的微观结构特征。发现聚合物中丙烯酰胺与丙烯酸钠单体单元的比例对其微观结构影响很大，并且从聚合物链段之间存在氢键和静电排斥这两种对立作用力相对强度的角度，定性地阐述各水凝胶微观结构之间的差异。     

聚丙烯酸钠在碳酸镁-水界面吸附的ESR研究

自旋标记;聚丙烯酸钠在碳酸镁-水界面吸附的ESR研究     

功能高分子聚丙烯酸铵的研制

以环己烷为连续相、水为分散相、氨水部分中和的丙烯酸为单体、K2S2O8为引发剂，N，N－亚甲基双丙烯酰胺为交联剂，采用反相悬浮聚合法合成了功能高分子材料－聚丙烯酸铵高吸水性树脂。研究了乳化剂、引发剂和交联剂用量、pH值、反应湿度等对吸水率的影响，得到的高吸水性树脂最大吸水率为1237mL/gR,其最大吸生理盐水率为114mL/gR。利用SEM，IR对其进行了表征。SEM分析表明，如果采取适当的工艺可以得到粒状产品。     

Determination of Polyacrylate Super Absorbent Polymers in Air

Abstract

A sampling and analytical method has been developed for measurement of a starch-grafted, cross-linked sodium polyacrylate in air. Also, the method is applicable to measurement of several other polyacrylate super absorbent polymers and involves air sampling with a 37-mm PVC membrane filter, treatment of the sample with 0.07 M cupric acetate solution to form a copper-polymer precipitate, digestion of the precipitate with nitric and perchloric acids, and measurement of the copper content by inductively-coupled plasma-atomic emission spectrophotometry. The interior surface of the front piece of the filter cassette also is analyzed. This analytical method has been compared with a sodium method that currently is used. Detection limits for various super absorbent polymers ranged from 4.4 to 14 micrograms per sample.     

壳聚糖─海藻酸钠微囊对蛋白质控制释放的研究

采用乳化法制备了可注射用壳聚糖海藻酸钠微囊, 其粒径小于２００ μｍ ,且具有相对较窄的近似高斯分布。牛血清白蛋白作为模型药物在微囊中的包埋率可超过５０ ％ 。通过壳聚糖在海藻酸钠微囊表面的复合,牛血清白蛋白从微囊中的持续释放时间从几个小时延长到半个月以上。     

Tunable Viscoelastic Properties of Sodium Polyacrylate Solution via CO2-Responsive Switchable Water

Upon stimulus by CO₂, CO₂-switchable viscoelastic fluids experience a deliberate transition between non-viscous and highly viscous solution states. Despite attracting considerable recent attention, most such fluids have not been applied at a large- scale due to their high costs and/or complex synthesis processes. Here, we report the development of CO₂-switchable viscoelastic fluids using commercially available sodium polyacrylate (NaPAA) and N,N-dimethyl ethanol amine (DMEA)-based switchable water. Upon bubbling CO₂, into the solutions under study, DMEA molecules are protonated to generate quaternary ammonium salts, resulting in pronounced decreases in solutions viscosity and elasticity due to the influence of increased ionic strength on NaPAA molecular conformations. Upon removal of CO₂ via introduction of N₂, quaternary salts are deprotonated to tertiary amines, allowing recovery of fluid viscosity and elasticity to near the initial state. This work provides a simple approach to fabricating CO₂-switchable viscoelastic fluids, widening the potential use of CO₂ in stimuli-responsive applications.     

高吸水性树脂聚丙烯酸钠盐制备工艺研究

研究他聚俩烯酸钠在溶液聚合中，引发剂、交联剂、丙烯酸中和度、单体浓度和反应温度对树脂吸水性的影响，从中获得最佳合成工艺，制得树脂性能为吸去离子水１４００ｇ／ｇ，吸０。９％ＮａＣｌ溶液１５０ｇ／ｇ，吸水速率快，保水性较好。     

Influnence of Sodium Polyacrylate on Crystallization and Aggregation of Butterfly-like Calcium Carbonate

Butterfly-like calcium carbonate(CaCO₃) particles were successfully prepared via a facile precipitation reaction of Na₂CO₃ with CaCl₂ in the presence of sodium polyacrylate(PAAS). The as-prepared samples were characterized with field emission scanning electron microscopy(FESEM), X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR). Butterfly-like CaCO₃ particles composed of three segment rods were obtained. Rod aggregates would act as the template for butterfly-like CaCO₃ crystals consisted of regular shaped crystallites with 150―200 nm in diameter. The influences of reaction temperature, the amount of PAAS and reaction time on the nucleation and growth of CaCO₃ crystals were investigated. The possible growth mechanism of CaCO₃ crystals was discussed. This research can not only make us further understand the general principles of the reaction, but also open up a new avenue of industrial production of CaCO₃ particles with exquisite and unique morphologies.