磺酸甜菜碱共聚物水溶液的黏度性质

通过自由基聚合制备了N,N-二甲基-N-甲基丙烯酰氧乙基-N-丁基磺酸铵(DMABS)及其与丙烯酸钠(NaAAc)、对乙烯基苯磺酸钠(NaSS)的均/共聚物。探讨了共聚物溶液的黏度行为随单体组成、聚合物浓度、离子强度与离子种类的变化关系,发现少量阴离子单体的引入可显著提高共聚物在水溶液中的比浓黏度;对于阴离子单体含量较低的共聚物,共聚物水溶液的特性黏数随着离子强度的增加而逐渐上升;而对于阴离子单体含量较高的共聚物,特性黏数随着离子强度的增加而迅速下降。     

丙烯酸-丙烯酰胺的反相悬浮聚合及吸水性能的研究

以环己烷为连续相,十六烷基磷酸单酯为悬浮稳定剂,N,N＇-亚甲基双丙烯酰胺为交联剂,过硫酸盐为引发剂,采用反相悬浮聚合法合成了高吸水性丙烯酸钠-丙烯酰胺交联共聚物。研究了共聚物吸水性能与交联剂、引发剂用量、丙烯酸中和度、共聚单体组成、水中所含电解质浓度以及共聚物粒度的关系。制得的共聚物吸去离子水可达700g/g以上,吸0.9％NaCl溶液70g/g以上。     

N-异丙基丙烯酰胺共聚物的温敏性

采用自由基水溶液聚合方法制备出了N-异丙基丙烯酰胺(N IPA)温敏共聚物P(AM-N IPA);首次在P(AM-N IPA)结构中引入丙烯酸钠(N aAA)单体结构单元,合成了离子型共聚物P(AM-N IPA-N aAA);考察了共聚物P(AM-N IPA)和P(AM-N IPA-N aAA)溶液温敏性的影响因素;分别采用荧光光谱分析法以及乌氏黏度计稀释法对共聚物溶液温敏机理进行了研究。结果表明,不同共聚单体的配比以及单体含量对共聚物溶液低临界溶解温度(LCST)均有显著影响;当温度高于共聚物低临界溶解温度时,共聚物分子链上的疏水基团的缔合作用增强,导致疏水聚集结构的形成,聚合物分子链发生去溶剂化作用,在共聚物稀溶液中表现为线团收缩,在共聚物亚浓溶液中表现为共聚物分子间聚集发生相分离。     

高吸水性三元共聚树脂的合成及性能研究

采用反相悬浮聚合法合成了丙烯酸钠－丙烯酰胺－甲基丙烯酸羟乙酯三元共聚物高吸水性树脂,研究了共聚物吸水性能与共聚物组成,交联剂用量,反应体系中油相水相比之间的关系;分析了共聚物吸水树脂的吸水溶胀动力学。实验结果表明,非离子性单体的引入,显著改善了共聚物吸水树脂的抗盐性能,土壤中添加０．２％的三元共聚树脂即可明显提高土壤的保水性能。     

Poly(DMAM-co-AA)水凝胶的合成

以N,N-二甲基丙烯酰胺(DMAM)与丙烯酸(AA)为单体,N,N-亚甲基双丙烯酰胺(NMBA)为交联剂,过硫酸铵为引发剂,采用水溶液聚合法合成了DMAM和AA的共聚物水凝胶。实验证明,加热温度、引发剂用量和反应体系中单体总浓度对聚合产物的吸水能力没有明显影响,但随着对反应溶液的加热温度升高、引发剂用量增大、单体总质量分数增大,聚合反应能够达到的最高温度就越高,达到最高温度的时间缩短。DMAM和AA的物质的量比偏离1越远,水凝胶的吸水能力越强。交联剂的质量分数为0.5%时,水凝胶的吸水能力最大。     

N-羟甲基丙烯酰胺/丙烯酸智能水凝胶的合成及性能研究

以N-羟甲基丙烯酰胺(N-MAM)和丙烯酸(AA)为聚合单体,过硫酸铵(APS)和N,N,N′,N′-四甲基乙二胺(TEMED)为引发体系,N,N-亚甲基双丙烯酰胺(MBA)为交联剂采用自由基水溶液聚合法合成了p(N-MAM-co-AA)水凝胶。研究了APS、MBA的用量、单体浓度与单体配比、溶液pH值和温度对水凝胶溶胀性能的影响,同时还研究了凝胶的溶胀-退溶胀动力学。     

自由基聚合法制备聚乙二醇双丙烯酸酯水凝胶

以过二硫酸胺(APS)/四甲基乙二胺(TMEDA)氧化-还原体系为引发体系,通过活性自由基溶液聚合法制备了交联网状聚乙二醇双丙烯酸酯(PEGDA)共聚物水凝胶支架,探讨了APS/TMEDA的引发聚合机理。研究结果表明,单体分子量越大,凝胶化时间越短,凝胶化时间随着PEGDA单体浓度的增大、温度的升高和加速剂用量的增大而减小。研究了不同单体浓度对水凝胶溶胀度及力学性能的影响,结果表明,单体溶液浓度越大,水凝胶的平衡溶胀率越小、压缩模量越强。     

明胶接枝共聚丙烯酸铵-丙烯酰胺

研究了溶液聚合法制备明胶-聚(丙烯酸铵-丙烯酰胺)(G-g-PAA/PAM)可降解高吸水性树脂的方法.对明胶/单体及丙烯酸铵/丙烯酰胺质量比、丙烯酸中和度、单体浓度及N,N'-亚甲基双丙烯酰胺和过硫酸钾相对含量影响产品吸(盐)水性能的情况进行测试,从中优选出较合适的反应条件,并用红外光谱对产物进行表征.该高吸水性树脂的吸水倍率达1187g/g,吸盐水倍率选82g/g.FTIR分析表明,反应产物为明胶与丙烯铵、丙烯酰胺的接枝共聚物.     

常压等离子体制备高吸水性树脂的研究

采用氩气冷弧等离子体处理丙烯酰胺,将活化的丙烯酰胺作为引发剂引发丙烯酰胺和丙烯酸钠共聚,研究了等离子体放电时间和功率、聚合温度、丙烯酰胺与丙烯酸钠的物质的量比、聚合溶液pH值、后聚合时间等因素对共聚物吸水性的影响。结果表明,获得了制备聚丙烯酰胺-丙烯酸钠的最佳工艺条件(放电时间90s,放电功率50W,单体配比1∶1,聚合温度30℃,溶液pH值为9,聚合时间3d),在该工艺条件下,所得树脂的吸水率高达560g/g聚合物。     

淀粉基吸水树脂的制备与性能分析

以淀粉、丙烯酸(AA)和丙烯酰胺(AM)为原料,采用过硫酸铵[(NH_4)_2S_2O_8]作为引发剂,利用N,N-亚甲基双丙烯酰胺(NMBA)进行交联,采用水溶液聚合法制备了AA-AM共聚淀粉吸水树脂。考察了丙烯酸溶液pH、丙烯酸单体用量、引发剂及交联剂用量、反应体系温度与时间对合成树脂性能的影响。通过性能测试和分析得出优化合成条件为:丙烯酸溶液pH=5.5,丙烯酸单体与葡萄糖剩基(AGU)摩尔比为7∶1,过硫酸铵用量为0.35mmol,交联剂用量为0.08571mmol,反应时间为65℃,反应温度为3h。在优化工艺下合成的树脂吸收蒸馏水、0.9%NaCl溶液量分别达到798.6g/g和95.7g/g。采用红外光谱(FT-IR)和热重分析(TG)对合成的树脂进行了表征与分析评价。     

聚磺酸甜菜碱与表面活性剂在水溶液中复合与相分离

通过浊点法研究了表面活性剂的结构与浓度对聚N、N-二甲基-N-甲基丙烯酰氧乙基-N-丁基磺酸铵（PDMABS）水溶液相分离温度的影响。选用的表面活性剂包括阴离子、阳离子和非离子型表面活性剂,以及大分子的聚丙烯酸、聚对乙烯基苯磺酸钠、聚甲基丙烯酰氧乙基二甲基苄基氯化铵。结果显示,各种表面活性剂对PDMABS有不同程度的增...     

盐水介质中分散聚合法制备两性聚电解质的研究

利用聚丙烯酰氧乙基三甲基氯化铵(PDAC)作为分散稳定剂,阴离子单体丙烯酸(从)、阳离子单体甲基丙烯酰氧乙基三甲基氯化铵(DMC)和非离子单体丙烯酰胺(AM)在硫酸铵水溶液中通过分散共聚合,制备了稳定分散在盐水中的聚合物微球.考察了无机盐浓度、分散剂用量对分散共聚合的影响.研究结果表明:体系内无机盐浓度的增加导致聚合物分子量降低;而随分散剂浓度的增加,微球粒径先减小后增加.制备的两性聚电解质溶液在等电点附近时,聚合物的特性黏度随盐浓度的增加而增加,显示明显的反聚电解质效应.     

羽毛蛋白-聚(丙烯酸-丙烯酰胺)高吸水性树脂的制备及吸水性能

以羽毛蛋白、丙烯酸和丙烯酰胺为原料,N,N′-亚甲基双丙烯酸胺为交联剂,过硫酸铵和亚硫酸氢钠为引发剂,采用水溶液聚合法制备了羽毛蛋白-聚(丙烯酸-丙烯酰胺)高吸水性树脂。研究了羽毛蛋白用量、引发剂用量、交联剂用量以及温度对树脂吸水倍率的影响,并考察了树脂的综合吸水性能。结果表明,树脂在蒸馏水和0.9%NaCl溶液中的吸水率分别为1152g/g和69.2g/g。树脂拥有较高的吸水速率,粒径80目以上的树脂在3min以内可达到吸水溶胀平衡,并且在较宽的pH值范围(pH=5～10)内的溶液中均有较高的吸水率。     

Surface modification and functionalization of electroactive polymer films via grafting of polyelectrolyte,polyampholyte and polymeric acids

Films of electroactive polymers, such as polyaniline (PAN) in its emeraldine base form, and poly(3-alkylthiophene), poly(3-hexylthiophene) (P6TH), poly(3-octylthiophene) (P8TH), and poly(3-dodecylthiophene) (P12TH) can be readily functionalized via thermal or near ultraviolet-light-induced surface graft copolymerization with monomers of polyelectrolyte, polyampholyte and polymeric acids. The monomers used in the present work include dimethyl sulphate quaternized dimethylamino-ethylmethacrylate (DMAEM·C₂H₆SO₄), 3-dimethyl(methacryloyloxyethyl)ammonium propane sulphonate (DMAPS), acrylic acid (AAc) and a sodium salt of styrene sulphonic acid (NaSS). The surface structures and compositions of the electroactive polymer films after functionalization via graft copolymerization were characterized by angle-resolved X-ray photoelectron spectroscopy. Graft copolymerization of poly(3-alkylthiophene) films, but not PAN films, with the hydrophilic monomers readily results in a stratified surface microstructure arising from the migration of the hydrophilic graft chains beneath a thin surface layer which is much richer in the substrate chains. On the other hand, graft copolymerization of PAN films with AAc and NaSS readily gives rise to a self-protonated (and thus conductive) surface structure.     

聚乙烯醇/聚丙烯酸/羟基磷灰石复合高吸水性树脂的制备及溶胀行为

以聚乙烯醇(PVA)、部分中和的丙烯酸(AA)和羟基磷灰石(HA)为原料,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聚乙烯醇/聚丙烯酸/羟基磷灰石(PVA/PAA/HA)复合高吸水树脂。考察了PVA用量对吸水性能的影响,研究了树脂在不同pH值溶液和不同阳离子盐溶液中的溶胀行为。结果表明,引入适量的PVA有利于树脂吸水性能的改善;树脂在pH=4～11较宽的范围内都能保持较高的吸水倍率,在CaCl2溶液中的溶胀动力学行为表现出明显的"过溶胀平衡现象"。     

Development of water-based liquid chromatography at the critical condition

Liquid chromatography at the critical condition (LCCC) is a chromatographic technique that allows for the isolation of one area of the polymer matrix so that other areas of the polymer may be probed with size-exclusion or adsorptive chromatographic modes. This technique has been successfully applied to the analysis of functionality distributions in functionalized oligomers and to polymer distributions within copolymers. Herein, the critical conditions of two polar polymers, poly(acrylic acid) and polystyrene sulfonate, are determined. These conditions were identified by varying buffer concentration, organic modifier within the mobile phase, or both. At the critical condition of poly(acrylic acid), the retention characteristics of a copolymer of acrylic acid and vinyl pyrrolidinone were determined. This extension to water-based mobile phase conditions will substantially broaden the possible applications of LCCC.     

聚（丙烯酸-CO-丙烯酰胺）／腐殖酸钠／高岭土复合高吸水性树脂的制备及溶胀行为

以N,N′-亚甲基双丙烯酰胺为交联剂、过硫酸铵为引发剂,采用水溶液聚合法合成了聚(丙烯酸-co-丙烯酰胺)/腐殖酸钠/高岭土多功能复合高吸水性树脂。研究了腐殖酸钠和高岭土含量对吸水倍率的影响,同时考察了该树脂的吸水速率及溶液pH值和不同阴阳离子对吸水倍率的影响。结果表明,在腐殖酸钠∶高岭土=2∶3(质量比)时树脂具有最高的吸水倍率,其吸蒸馏水和0.9%(质量分数)NaCl溶液分别达到450 g/g和39 g/g。     

Radiation Synthesis and Magnetic Property Investigations of the Graft Copolymer Poly(Ethylene-g-Acrylic Acid)/Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> Film

In this work, acrylic acid (AAc) monomer was grafted onto low-density polyethylene (LDPE) films by the direct method to obtain acid (LDPE-grafted poly(acrylic acid) (LDPE-g-PAAc)) graft copolymers. The presence of the grafted PAAc with COOH groups allows coupling with Fe^2+/3+ ions. The stabilization of Fe₃O₄ particles onto the graft copolymers was done by in situ reduction of LDPE-g-PAAc/Fe^2+/3+ with sodium borohydride (NaBH₄) in aqueous solution. The LDPE-g-PAAc graft copolymer and LDPE-g-PAAc/Fe₃O₄ composite films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and electron spin resonance (ESR). The synthesized composites exhibit excellent magnetic properties. The results indicated that the magnetic oxide (Fe₃O₄) was embedded and homogenously dispersed into the surfaces of the graft copolymer films as indicated by SEM. The FT-IR analysis clearly suggests that an AAc monomer was effectively grafted onto LDPE. The XRD studies elucidate the change in the crystallinity of the graft copolymers.

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Graphical Abstract The procedures for magnetic film manufacture LDPE-g-PAAc/Fe₃O₄ using gamma irradiation technique

     

Synthesis and characterization of amphiphilic star-shaped copolymers based on β-cyclodextrin for micelles drug delivery

Purpose: A series of β-CD amphiphilic star-shaped copolymers with exceptional characteristics were synthesized and their potential as carriers for micelles drug delivery was investigated.

Methods: A series of amphiphilic copolymers based on β-CD were synthesized by introducing poly (acrylic acid)-co-poly(methyl methacrylate)-poly (vinyl pyrrolidone) or poly (acrylic acid)-co-poly(methyl methacrylate)-co-poly(monoacylated-β-CD)-poly (vinyl pyrrolidone) blocks to the primary hydroxyl group positions of β-CD. The micellization behavior of the copolymers, the synthesis conditions, characteristics, drug release in vitro and tissue distribution of vinpocetine (VP) micelles in vivo were investigated.

Results: Around 60 types of β-CD amphiphilic star-shaped copolymers were successfully synthesized and the critical micelle concentration ranged from 9.80?×?10^?4 to 5.24?×?10^?2g/L. The particle size, drug loading and entrapment efficiency of VP-loaded β-CD-P₄ micelles prepared with optimal formulation were about 65?nm, 21.44?±?0.14%, and 49.05?±?0.36%, respectively. The particles had good sphericity. The cumulative release rates at 72?h of VP-loaded β-CD-P₄ micelles in pH 1.0, pH 4.5, pH 6.5, or pH 7.4 media were 93%, 69%, 49%, and 43%, respectively. And, the lung targeting efficiency of VP-loaded β-CD-P₄ micelles was 8.98 times higher than that of VP injection.

Conclusion: The VP-loaded β-CD-P₄ micelles exhibited controlled-release property, pH-induced feature and lung targeting capacity compared with VP injection, suggesting that the β-CD-P₄ copolymers are an excellent candidate for micelles drug delivery.     

智能型AMPS/DMAEMA水凝胶的电敏感性能

以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)为单体,N,N′-亚甲基双丙烯酰胺为交联剂,过硫酸铵和亚硫酸氢钠为氧化还原引发剂,采用水溶液聚合法制备了AMPS/DMAEMA水凝胶,考察了样品水凝胶在外加直流电场刺激下的消溶胀动力学和弯曲行为.结果表明,DMAEMA单体含量和施加电压大小对水凝胶的电敏感性能有着显著影响.用一级动力学方程能够较好地描述水凝胶在接触电压刺激下的消溶胀过程.在非接触电压刺激下,单体摩尔比,n(AMPS):n(DMAEMA)=9:1的水凝胶向负极弯曲;单体摩尔比n(AMPS):n(DMAEMA)=5:5的水凝胶向正极弯曲;单体摩尔比n(AMPS):n(DMAEMA)=7:3的水凝胶随着非接触电压的增大,出现先向负极弯曲,后向正极弯曲的现象.