羟乙基纤维素/AMPS接枝共聚物与大豆分离蛋白形成聚离子复合物研究

用硝酸铈铵/硝酸(CAN/HNO3)引发了羟乙基纤维素(HEC)与2-丙烯酰胺基-2-甲基丙磺酸(AMPS)的接枝共聚反应.研究了单体浓度、引发剂浓度和反应温度对接枝率的影响.由于强酸型基团磺酸基的引入,接枝共聚物带有了阴离子电荷,在小于大豆分离蛋白等电点(pH=4.5)的缓冲溶液(pH=1.5)中,通过接枝共聚物的阴离子电荷与大豆分离蛋白(SPI)阳离子电荷之间的静电相互作用,可以形成HEC-g-PAMPS/SPI聚离子复合物.以聚离子复合物负载模型药物布洛芬(Ibuprofen),在37℃于不同pH的缓冲溶液中进行了体外释放研究.药物释放速率的测定表明,以HEC-g-PAMPS/SPI聚离子复合物作为布洛芬的载体,可以在选择性条件下实现药物可控释放的目的.     

温敏性PCL-PEG-PCL水凝胶的合成、表征及蛋白药物释放

考察了温敏性PCL-PEG-PCL水凝胶中聚乙二醇(PEG)及聚己内酯(PCL)不同嵌段组成对其溶胶-凝胶相转变温度以及亲水性药物(牛血清白蛋白, BSA)释放速率的影响. 采用开环聚合法, 以辛酸亚锡为催化剂、PEG1500/PEG1000为引发剂, 与己内酯单体发生开环共聚, 合成了一系列具有不同PEG和PCL嵌段长度的PCL-PEG-PCL型三嵌段共聚物. 通过核磁共振氢谱及凝胶渗透色谱对其组成、结构及分子量进行了表征. 共聚物的溶胶-凝胶相变温度由翻转试管法测定. 利用透射电镜、核磁共振氢谱及荧光探针技术证实了该材料在水溶液中胶束的形成. 以BSA为模型蛋白药物, 制备载药水凝胶, 利用microBCA法测定药物在释放介质中的浓度, 研究其体外释放行为. 实验结果表明, 共聚物的溶胶-凝胶相变温度与PCL及PEG嵌段长度紧密相关, 即在给定共聚物浓度情况下, 固定PEG嵌段长度而增加PCL嵌段长度, 会导致相变温度降低; 而固定PCL嵌段长度而增加PEG嵌段长度, 其相变温度相应升高. 水凝胶中蛋白药物的释放速率与疏水的PCL嵌段长度无关, 而与亲水的PEG嵌段长度密切相关, 即PEG嵌段越长, 蛋白药物释放越快.     

聚合物驱蚊剂的慢释放研究

本文研究了丙烯酸酯共聚物载体对驱蚊剂N,N-二乙基间甲苯酰胺(DETA)慢释放行为的控制,探讨了单体配比、共聚物分子量以及DETA含量对释放速率的影响。结果表明。增加亲水性单体丙烯酸(AA),可提高DETA的释放速率;降低共聚物数均分子量,会减少DETA的释放量;剂型中DETA含量与释放量存在线性正比关系,但DETA的含量增加并不导致释放有效时间的线性增加。本文还就共聚物膜的透湿性和碱溶性作了研究,亲水性单体AA的增加同样导致透湿性和碱溶性的增加。制备的聚合物驱蚊剂经现场应用试验,表明具有良好的长效驱蚊特性。     

pH敏感性P(AM-AA-co-C8PhEO10Ac)水凝胶溶胀动力学及其对茶碱的控释

以丙烯酰胺(AM)、丙烯酸(AA)和丙烯酸辛基酚聚氧乙烯醚酯(C8PhEO10Ac)为单体,采用自由基交联共聚法合成了具有pH敏感性的P(AM-AA-co-C8PhEO10Ac)水凝胶.研究了pH、单体配比对凝胶溶胀性能、溶胀动力学和退溶胀动力学的影响.初步探讨了模拟胃液(pH=1.4)、肠液(pH=7.4)中水凝胶对茶碱的控释情况.结果表明:凝胶具有高溶胀、退溶胀速率和良好的pH敏感性等特征;水凝胶的扩散行为在pH=7.4的缓冲溶液中为非Fickian扩散模式;载药凝胶在模拟肠液中对药物的累积释放率明显大于胃液中的累积释放率,其中n(C8PhEO10Ac)∶n(AM)∶n(AA)为1∶20∶30的载药水凝胶对茶碱的累积释放率最大.     

疏水缔合水溶性聚合物——P(AM-NaAA-DiAC_8)的合成及其缔合性能

以双烯丙基胺和1-溴代辛烷为原料,合成了疏水单体N,N-双烯丙基辛胺(DiAC8).采取前加碱二元胶束共聚-共水解法合成了三元疏水缔合水溶性聚合物--聚(丙烯酰胺-丙烯酸钠-N,N-双烯丙基辛胺)[P(AM-NaAA-DiAC8)]. DiAC8和P(AM-NaAA-DiAC8)的结构经1H NMR和FT-IR表征.以芘为荧光探针,利用稳态荧光光谱法研究了P(AM-NaAA-DiAC8)在水溶液中的缔合行为,结果表明当r(DiAC8)=0.1%～1.4%时,随聚合物浓度、疏水单体用量的增加,P(AM-NaAA-DiAC8)在二次蒸馏水和1 mol·L-1NaCl水溶液中的Ⅰ1/Ⅰ3值减少.表明P(AM-NaAA-DiAC8)缔合行为取决于聚合物浓度、疏水单体用量及介质的极性.     

丙烯酰胺—烯丙基磺酸钠共聚物的絮凝性能

丙烯酰胺与含磺酸基单体的共聚物用于提高石油回采率已有不少报道,如乙烯基磺酸、丙烯酸磺丙酯、苯乙烯磺酸、2-丙烯酰胺基-2-甲基丙磺酸和甲基丙烯酸磺乙酯。亦有文献提到用丙烯酰胺与烯丙基磺酸钠共聚物,但缺乏详细报道。国内油田钻井液处理剂中的PAC_(142)和PAC_(143)是丙烯酰胺、烯丙基磺酸钠及其它单体的多元共聚物;日本的钻井液处理剂G-20LL是丙烯酰胺、烯丙基磺酸钠和丙烯酸的三元共聚物。本文报道丙烯酰胺与烯丙基磺酸钠的共聚合及产物的絮凝性能。     

pH敏感两亲性嵌段共聚物胶束的制备及其负载紫杉醇体外药效的研究

采用可逆加成-断裂链转移(RAFT)聚合法,以丙烯酸(AA)、丙烯酸异丁酯(IBA)无规共聚物与聚丙烯酸-2-羟丙酯(PHPA)反应,制备了具有pH敏感性的两亲性嵌段共聚物(P(IBA-co-AA)-b-PHPA).用红外光谱(FTIR)、核磁共振(1H-NMR)、凝胶渗透色谱(GPC)对其结构进行表征.此共聚物在水溶液中可自组装形成胶束,临界胶束浓度约为2.0mg/L.由透射电子显微镜(TEM)、动态光散射(DLS)表征可知胶束为尺寸约100nm的球形颗粒;用DLS观察到胶束粒径随pH值的升高而逐渐增大.以抗癌药物紫杉醇为模型药物,研究载药胶束在模拟人体环境中的控释行为.用CellCountingKit-8(简称CCK-8)法分别研究聚合物胶束对MCF-7人乳腺癌细胞和A549人肺癌细胞的细胞毒性,并评价载药胶束在两细胞中的抗癌效果.结果表明,P(IBA-co-AA)-b-PHPA可作为包载紫杉醇的一种新型纳米材料,载药胶束的体外释放呈明显pH依赖性,且具有较好的体外抗肿瘤活性,有望成为理想的抗肿瘤药物载体.     

无皂乳液聚合制备含铕荧光共聚物乳液的研究及其表征

以丙烯酸(AA)为第一配体、邻菲罗啉(Phen)为第二配体、Eu3+为中心离子,合成了一种可聚合的稀土铕配合物.以配合物单体、甲基丙烯酸甲酯、丙烯酰胺和对苯乙烯磺酸钠为共聚单体,通过无皂乳液聚合的方法,制备了含铕荧光共聚物乳液.采用红外光谱对共聚物的结构进行了表征,并探讨了配合物单体含量对共聚物乳液性能的影响.透射电子显微镜(TEM)和激光光散射粒度仪(PCS)测试结果表明,共聚物乳液形成了相对均一的球状结构,但随着配合物单体含量增加,共聚物微球粒径逐渐增大、分散性变差.采用荧光分光光度计测试了共聚物乳液的荧光性能,在594和619 nm处出现Eu3+的特征发射光谱,且荧光强度随着配合物单体含量增加而增强.     

疏水化修饰的聚N-异丙基丙烯酰胺高分子的水溶液性质研究

为了研究不同疏水化修饰的聚Ｎ 异丙基丙烯酰胺（ＰＮＩＰＡＭ）高分子的水溶液性质,合成了一系列Ｎ 异丙基丙烯酰胺（ＮＩＰＡＭ）和长链丙烯酸酯及丙烯酸胆固醇酯的共聚物．利用表面张力法证实了该类共聚物在室温下都具有良好的表面活性,在水溶液中能够形成胶束．利用荧光探针法,研究了共聚物的低温临界溶液温度（ＬｏｗｅｒＣｒｉｔｉｃａｌＳｏｌｕｔｉｏｎＴｅｍｐｅｒａｔｕｒｅ,ＬＣＳＴ）,发现,随着丙烯酸酯碳链及其配比（摩尔投料比）的变化,共聚物的ＬＣＳＴ变化不明显,但它们都比均聚的ＰＮＩＰＡＭ要低;利用荧光偏振法研究了共聚物在水溶液中的微粘度,发现其微粘度不随共聚物中丙烯酸酯链长和配比的变化而变化,说明了该类共聚物在室温下能够形成相类同的胶束内核．     

P(DMAA-co-AM)水凝胶制备及其固定α-淀粉酶研究

采用氧化还原引发体系,水溶液聚合法制备P(DMAA-co-AM)水凝胶,并以其作为载体固定α-淀粉酶。采用单一变量法研究交联剂(N,N’-亚甲基双丙烯酰胺)用量、引发剂(过硫酸铵)用量、单体浓度和单体配比对凝胶性能的影响。以水凝胶的最大平衡溶胀度为指标,得出制备P(DMAA-co-AM)水凝胶的优化条件:交联剂用量为0.3%,引发剂用量为0.6%,单体浓度为20%,N,N′-二甲基丙烯酰胺与丙烯酰胺的摩尔比为2∶1。在优化条件下,采用原位聚合法固定α-淀粉酶,测定不同单体配比的P(DMAA-co-AM)水凝胶固定化α-淀粉酶的活性。     

Synthesis and Properties of Poly(AAm‐KMA‐MA) Hydrogels

In this investigation, poly(acrylamide‐co‐potassium methacrylate‐co‐maleic acid) hydrogels, poly(AAm‐KMA‐MA) were synthesized by redox copolymerization in aqueous solution. The effect of reaction parameters, such as concentration of maleic acid, crosslinking agent, initiator and activator, on the swelling behavior was investigated in detail. The swelling/diffusion characteristics were also evaluated for 1,4‐butanediol diacrylate (BDDA) and 1,2‐ethyleneglycol dimethacrylate (EGDMA) crosslinked hydrogels having different amounts of maleic acid. The results indicate that the water diffusion of hydrogels was of a non‐Fickian type. The hydrogels were characterized by IR spectroscopy and thermogravimetric analysis (TGA). Their surface characteristics were observed by using scanning electron microscopy (SEM). Furthermore, their swelling phenomena in different pH and salt solutions and simulated biological fluids was also studied.     

Adsorption of bovine serum albumin to acrylamide–itaconic acid hydrogels

In this study, acrylamide–itaconic acid hydrogels containing different amounts of itaconic acid prepared by irradiating with γ radiation are discussed. They have been used in experiments of swelling, diffusion and bovine serum albumin (BSA) adsorption. Maximum and minimum swellings were observed with water (1520%) and BSA (890%), respectively. Diffusion of water, NaCl and BSA within hydrogels were found to be non-Fickian in character. In the experiments of BSA adsorption, type III adsorption was found. The hydrogel prepared with 60 mg itaconic acid and irradiated at 2.00 kGy was found to be the best adsorption system for BSA. The adsorption capacity of acrylamide–itaconic acid hydrogel was found to exceed that of acrylamide hydrogel by more than 80–100%.     

Characterization of structured acrylamide/acrylic acid hydrogels by TMDSC and microscopy

The thermal behavior of hydrogels synthesized by solution polymerization between acrylamide, acrylic acid and diglycidyl acrylate (DGA) as a crosslinking agent was investigated. The structure of the hydrogel can be tightly controlled with the reaction temperature. This method produces a new type of hydrogels, which exhibit well defined structures at various scales of length simultaneously. These multi-structured hydrogels are hydrophilic, elastic, water insoluble, and soft polymers with an anisotropic optical response. The structure was observed by scanning electron microscopy (SEM), polarized light microscopy (PLM) and macroscopic visualization (CCD camera). In addition, structural transitions in the hydrogels were monitored by temperature modulated differential scanning calorimetry (TMDSC). Severe heating tests in an adiabatic oven were performed to analyze decomposition of the material. Fourier transform infrared (FTIR) spectroscopy was used to qualitatively analyze the hydrogels samples exposed to a sudden thermal treatment.     

Synthesis and degradation of intelligent hydrogels containing polyacetal segments

Intelligent hydrogels were first obtained by copolymerization of telechelic poly(1,3-dioxolane) (pDXL) with acrylic acid, acrylamide, N-isopropylacrylamide respectively. The synthesis and characterization of the networks were discussed. The swelling behavior of the hydrogel was dependent on the solubility parameter of the solvents and hydrogels. The networks containing polyacetal segments (pDXL) can degrade by acid in different solvents. DXL and few other cycle molecules measured by GC-MS analysis were formed after degradation. According to the degradation products, the polymerization mechanism can be testified.     

结肠位点药物传载凝胶的溶胀动力学研究

合成了带不同疏水侧基的甲基丙烯酸酯、甲基丙烯酰胺及丙烯酸与 4,4′ 二 (甲基丙烯酰胺基 )偶氮苯交联共聚的凝胶 .主要研究了这类凝胶在pH =2 .2至pH =7.4的缓冲溶液的溶胀特性 .其溶胀过程遵循二级溶胀动力学 ,影响这类凝胶溶胀行为的因素包括交联程度、疏水基链的长度、pH值等 .通过调节这些因素是完全可以控制凝胶在小肠内的溶胀程度 ,进而避免凝胶内部的药物被提前释放     

Swelling behavior of ionically cross-linked polyampholytic hydrogels in varied salt solutions

Ionically cross-linked polyampholytic hydrogels were synthesized by redox copolymerization of acrylamide and an ionic complex of (N,N-diethylamino)ethyl methacrylate and acrylic acid (designated as PADA hydrogel). The swelling behavior of the hydrogels in water indicated that a minimal equilibrium swelling ratio is found when the molar ratio of anionic/cationic monomers was 1.55. In NaCl solution, the hydrogels exhibited the typical swelling behavior of conventional polyampholytic gels. Their equilibrium swelling ratios increased with an increase in the NaCl concentration. In solutions of multivalent ions (CaCl₂ and trisodium citrate solutions), the equilibrium swelling ratios of the hydrogels increased first and were then followed by a decrease with an increase in salt concentration. Interestingly, an unexpected abrupt swelling phenomenon was observed when the fully swollen hydrogels in salt solution were transmitted to pure water. The unique swelling behavior of PADA hydrogels depends not only on the molar ratio of the anionic/cationic monomers but also on the valency of the ions.     

Modeling of Swelling Behaviors of Acrylamide-Based Polymeric Hydrogels by Intelligent System

Hydrogels based on acrylamide (AAm) were synthesized by free radical polymerization in an aqueous solution using N,N’-methylenebisacrylamide (MBAAm) as crosslinker. To obtain anionic hydrogels, 2-acrylamido-2-methylpropanesulfonic acid sodium salt (AMPS) and acrylic acid (AAc) were used as comonomers. The swelling behaviors of all hydrogel systems were modeled using an artificial neural network (ANN) and compared with a multivariable least squares regression (MLSR) model and phenomenal model. The predictions from the ANN model, which associated input parameters, including the amounts of crosslinker (MBA) and comonomer, and swelling values with time, produce results that show excellent correlation with experimental data. The parameters of swelling kinetics and water diffusion mechanisms of the hydrogels were calculated using the obtained experimental data. Model analysis indicated that the ANN models could accurately describe complex swelling behaviors of highly swellable hydrogels.     

聚丙烯酰胺/聚异丙基丙烯酰胺互穿网络水凝胶的制备与性能

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.     

A study on the swelling behavior of poly(acrylic acid) hydrogels obtained by electron beam crosslinking

Poly(acrylic acid) (PAA) hydrogels were prepared by using electron beam (EB) crosslinking of PAA homopolymer from its aqueous solutions. The swelling behavior of the hydrogels was studied as a function of the concentration of PAA solution, radiation dose, pH of the swelling medium and swelling time. Also the environmental pH effect on the water diffusion mode into hydrogels was investigated. These hydrogels clearly showed pH-sensitive swelling behavior with Fickian type of diffusion in the stomach-like pH medium (pH 1.3) and non-Fickian type in the intestine-like pH medium (pH 6.8).     

Collagen-based highly porous hydrogel without any porogen: Synthesis and characteristics

In this contribution we have developed a collagen-based highly porous hydrogel by neutralizing the grafted poly(acrylamide-co-acrylic acid) after gel formation. Preparation of the hydrogels involved free radical polymerization of a combination of hydrolyzed collagen, acrylic acid (AA), acrylamide (AAm) and distilled water, in appropriate amounts and contained a crosslinking agent called N,N′-methylene bisacrylamide (MBA). The chemical structure of the hydrogels was characterized by means of FTIR spectroscopy, DSC and TGA thermal methods. Morphology of the samples was examined by scanning electron microscopy (SEM). Systematically, the certain variables of the graft copolymerization were optimized to achieve maximum swelling capacity. The absorbency under load (AUL) and centrifuge retention capacity (CRC) were measured. The swelling ratio in various salt solutions was also determined and additionally, the swelling of hydrogels was measured in solutions with pH ranged 1-13. The synthesized hydrogel exhibited a pH-responsiveness character so that a swelling-collapsing pulsatile behavior was recorded at pH 2 and 8.