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1.
β-环糊精大分子单体/N-异丙基丙烯酰胺共聚水凝胶   总被引:3,自引:0,他引:3  
采用顺丁烯二酸酐(MAH)对水溶性β-环糊精(β-CD)树脂(β-CD-EPI)进行了改性,合成出一种新型功能性大分子单体MAH-β-CD-EPI。通过MAH-β-CD-EPI与N-异丙基丙烯酰胺(NIPA)共聚反应合成出温度及pH敏感性MAH-β-CD-EPI/NIPA水凝胶。用元素分析、红外光谱及DSC对水凝胶进行了表征。结果表明.水凝胶在所研究的NIPA含量范围内(53.0%~82.3%(质量),均表现出明显的温度及pH敏感性,并且其体积相变温度(Tc)与它的组成及环境pH有关。  相似文献   

2.
为了研究溶胀体积可随外界环境因素智能变化的吸水凝胶,用微波等离子体预辐射引发聚合P(AMPS/NIPA)新型二元水凝胶.探讨了等离子体预辐射时间、等离子体预辐射功率、交联剂浓度、单体配比和总单体浓度等因素对二元水凝胶吸水倍数的影响,对合成工艺进行了优化.研究了水凝胶的温度敏感性、pH敏感性,并用红外光谱对P(AMPS/NIPA)水凝胶官能团进行了表征.研究表明,微波等离子体预辐射引发聚合制备的P(AMPS/NIPA)二元智能凝胶具有高的吸水倍数、很好的温度敏感性和pH敏感性,是综合性能优秀的智能水凝胶.  相似文献   

3.
通过阴离子型端丙烯酸酯基聚氨酯(UAA)与N-异丙基丙烯酰胺(NIPAAm)的共聚交联反应,制备了pH/温度敏感性水凝胶,分析了水凝胶的结构形态及溶胀水的状态.结果表明,凝胶相结构均匀,随聚氨酯含量的降低,凝胶的骨架变得松散,并且孔道结构增大,导致溶胀凝胶中不可冻结水含量及凝胶强度的降低.  相似文献   

4.
有机硅聚氨酯丙烯酸酯预聚物的合成、表征及感光性   总被引:13,自引:0,他引:13  
以异佛尔酮二异氰酸酯(IPDI)、烷羟基硅油、丙烯酸β-羟乙酯(HEA)为原料,合成了一种有机硅聚氨酯丙烯酸酯预聚物(ISAE)。探讨了原料结构、反应温度、合成方法等因素对反应的影响,确定最佳反应条件为:反应温度低于80℃,合成方法为过量IPDI先与烷羟基硅油反应,然后再与HEA反应。表征了ISAE的结构,ISAE是含硅聚氨酯丙烯酸酯和不含硅聚氨酯丙烯酸酯的混合物。研究了ISAE感光体系的感度,发现ISAE感光体系具有很高感光性,感度值为12.3mJ/cm^2,其紫外响应峰为333nm。  相似文献   

5.
智能聚氨酯水凝胶的合成及性能研究   总被引:1,自引:0,他引:1  
以聚乙二醇(PEG-200、400、600)、二羟甲基丙酸(DMPA)、2,4-甲苯二异氰酸酯(TDI)及N,N'-二乙基丙烯酰胺(DEAAm)等为原料合成了3种对pH值、温度、离子强度等敏感的智能聚氨酯水凝胶,研究了智能聚氨酯水凝胶溶胀率(SR)受pH值、温度、离子强度等因素的影响.结果表明,合成的聚氨酯水凝胶具有良好的pH、温度、离子强度敏感性,并具有良好的溶胀-退胀可逆性.  相似文献   

6.
用丙烯酸(ARc)对壳聚糖(CS)进行化学改性,合成反应中问体壳聚糖衍生物CS-ARc,进一步合成不同配比的CS-ARc与N-异丙基丙烯酰胺(NIPA)的共聚凝胶P(CS-AAc-NIPA),通过红外光谱和元素分析等表征了产物的结构和组成,并研究了P(CS—ARc-NIPA)凝胶在水中和细胞培养基中的溶胀性能.结果表明共聚凝胶在水中和培养基中均显示较好的温度敏感性.对P(CS-ARc-NIPA)共聚凝胶进行细胞培养研究发现,其表面可成功种植成纤维细胞(L929),细胞贴附生长情况良好,表明材料具有很好的细胞相容性.当环境温度降低后,共聚凝胶发生疏水.亲水变化,导致其表面细胞自动脱附,从而避免了使用酶解法脱附细胞造成的细胞功能损伤.’  相似文献   

7.
以大分子单体甲基丙烯酸环氧酯(EMA)与亲水性单体甲基丙烯酸-β-羟乙酯(HEMA)为原料,双甲基丙烯酸乙二醇酯(EDMA)为交联剂,采用本体聚合方法合成了一系列新型水凝胶.从宏观方面研究了EMA含量、温度对水凝胶溶胀、拉伸性能的影响,进而研究了水凝胶的交联网络结构参数.EMA含量的增大加强了水凝胶内部疏水基团间的相互作用,使平衡含水EWC降低,聚合物体积分数φ2增大,拉伸强度、杨氏模量、有效交联密度υe以及聚合物-水相互作用参数χ也随之增大,网链分子量Mc减小.当温度由275 K升至304 K,水凝胶样品EMA25/HEMA75的EWC值下降,φ2值和χ值增大.  相似文献   

8.
以氢化二苯基甲烷二异氰酸酯(H12MDI)、多元醇为主要原料,采用半预聚体法合成聚氨酯弹性体。结果表明,合成聚氨酯预聚物较佳的工艺条件为:异氰酸根指数R为4,在50℃的条件下反应1h后,80℃条件下反应2h,预聚物黏度3900mPa·s左右,黏度适中。同时考察了催化剂种类、固化温度、固化时间、多元醇种类和分子量、多元醇交联剂等对聚氨酯力学性能和光学性能的影响,确定合成透明聚氨酯弹性体较好的条件为以TK233为催化剂,以多元醇NJ210、NJ3050为原料,室温固化72h,此种方法合成的聚氨酯具有较好的透光率和力学性能。  相似文献   

9.
本发明公开了一种聚氨酯薄膜,其中薄膜由聚氨酯分散液制备,分散液山非离子聚氨酯预聚物制备,并且预聚物由聚氨酯预聚物配方制备,所说的配方中包括二异氰酸酯和含活性氢的物质。分散液分两步或更多步过程形成,其中第一步形成预聚物,并且在随后的步骤中,在阴离子表面活性剂的存在下形成预聚物的水分散液,这两个步骤在基本上不存在有机溶剂的情况下进行。  相似文献   

10.
聚氨酯弹性体隔振性能分析   总被引:1,自引:0,他引:1  
采用TDI和MDI通过预聚物法进行浇注型聚氨酯弹性体的合成。分析预聚物中异氰酸酯基含量和扩链剂的种类对聚氨酯弹性体力学性能的影响。浇注型聚氨酯隔振器与橡胶隔振器相比,具有更低的固有频率、更好的动态性能和更高的承载能力。疲劳试验结果表明聚氨酯隔振器具有优良的抗疲劳性能。  相似文献   

11.
Poly(ethylene glycol) methylether acrylate (PEGMEA) and tetraethylene glycol diacrylate (TEGDA) were first synthesized. The thermosensitive hydrogels were then prepared from N-isopropylacrylamide (NIPAAm), PEGMEA, and three crosslinkers with different structures such as N, N′-methylene-bis-acrylamide (NMBA), TEGDA, and poly(ethylene glycol) dimethacrylate (EGDMA). The influence of polymerization factors such as the kind and amount of crosslinker and initial total monomer concentration on the swelling behavior, gel strength, effective crosslinking densities, and number-average molecular weight between crosslink points ( ) for the present copolymeric hydrogels was investigated. The results indicate that the swelling ratios for the present copolymeric gels decrease with increase in temperature. In addition, the results also showed that the higher swelling ratios for the present gels prepared from TEGDA were obtained due to the larger space between the gel networks. The crosslinking density depends on the swelling ratio and the kind and extent of crosslinker. In addition, the drug release behavior for the present copolymeric gels was investigated.  相似文献   

12.
This study describes the synthesis of magnetite/amphiphilic polymer composite nanoparticles that can be potentially used simultaneously for cancer diagnosis and therapy. The synthesis method was a one-shot process wherein magnetite nanoparticles were mixed with core-crosslinked amphiphilic polymer (CCAP) nanoparticles, prepared using a copolymer of a urethane acrylate nonionomer (UAN) and a urethane acrylate anionomer (UAA). The CCAP nanoparticles had a hydrophobic core and a hydrophilic exterior with both PEG segments and carboxylic acid groups, wherein the magnetite nanoparticles were coordinated and stabilized. According to DLS data, the ratio of UAN to UAA and the ratio of magnetite to polymer are keys to controlling the size and thus, the stability of the composite nanoparticles. The magnetic measurement indicated that the composite nanoparticles had superparamagnetic properties and high saturation magnetization. The preliminary magnetic resonance imaging showed that the particles produced an enhanced image even when their concentration was as low as 80 microg/ml.  相似文献   

13.
A poly (N-isopropylacrylamide) (PNIPA) hydrogel was synthesized by free radical polymerization and reinforced with a polyurethane foam to make a hydrogel composite. The temperature dependence of the elastic modulus of the PNIPA hydrogel and the composite due to volume phase transition was found using a uniaxial compression test, and the swelling property was investigated using an equilibrium swelling ratio experiment. The gel composite preserves the ability to undergo the volume phase transition and its elastic modulus has strong temperature dependence. The temperature dependence of the elastic modulus and swelling ratio of the gel composite were compared to the PNIPA hydrogel. Not surprisingly, the modulus and swelling ratio of the composite were less dramatic than in the gel.  相似文献   

14.
首先研究了液-液静态界面聚合反应界面处的pH值与反应时间的关系,然后以聚甲基丙烯酸N,N-二甲氨基乙酯(PDM AEM A)作为交联预聚物,利用双苄基试剂进行季铵化反应,在聚砜基膜表面固载PDM AEM A凝胶层,制得荷正电的复合纳滤膜。研究了pH值与凝胶层溶胀度和复合膜分离性能的关系。实验表明,界面聚合产生的季铵盐有两相相容性,在反应中起到自催化作用;此膜面界面聚合在特定的pH值范围才能得到性能良好的纳滤膜;PDM AEM A水凝胶层随pH值的变化溶胀度有明显变化;所制得的复合纳滤膜具有pH敏感性。  相似文献   

15.
基于SAP吸水膨胀橡胶的耐温耐盐性能   总被引:2,自引:0,他引:2  
以反相悬浮聚合法合成P(AANa/AMPS/DMDAAC)两性共聚高吸水树脂(SAP),并引发溶胀在SAP中的丙烯酸丁酯和丙烯酸进行原位共聚合,制备疏水改性高吸水树脂。将丁腈橡胶、改性高吸水树脂、补强剂和其他助剂借助混炼机混炼均匀,在硫化成型机上高温硫化制备吸水膨胀橡胶(WSR)。研究盐溶液种类、盐溶液浓度以及环境温度对WSR的质量吸水膨胀倍率的影响,并对吸水后的WSR进行热重分析。结果表明:盐溶液中阳离子浓度越大,化合价越高,对WSR吸水性能影响越明显,吸液膨胀倍率越小;在对WSR进行一系列不同温度下的吸液性能研究时发现,WSR在120℃具有较好的吸水膨胀性能。在环境温度达到175℃时,WSR达到失水平衡。  相似文献   

16.
采用离子凝胶法制备了欧车前胶-g-聚丙烯酸/凹凸棒黏土/海藻酸钠(PSY-g-PAA/APT/SA)载药复合凝胶小球,以双氯芬酸钠为模型药物,考察了pH敏感性和凹凸棒黏土含量对凝胶小球的包封率、载药率、溶胀性能和药物释放行为的影响。结果表明,当释放介质为模拟胃液(pH=1.2)时,药物基本不释放;而为模拟肠液(pH=6.8)时,5h后累积释放率超过90%,复合凝胶小球具有明显的pH敏感性。随着凝胶小球中凹凸棒黏土含量的增加,溶胀率和药物累积释放率均减小,表明凹凸棒黏土的引入可以减缓药物的突释效应。  相似文献   

17.
PVA/P(AA-AM)复合水凝胶的制备及性能   总被引:2,自引:0,他引:2  
采用水溶液聚合方法合成了不同组成的丙烯酸-丙烯酰胺共聚物(P(AA-AM))。将聚乙烯醇(PVA)与所合成的P(AA-AM)共混,以戊二醛为交联剂,制备出了不同结构的PVA/P(AA-AM)复合水凝胶。采用扫描电镜观察了凝胶形貌,研究了复合水凝胶的结构与性能关系。结果表明,复合水凝胶溶胀性能与所用交联剂加量有关,复合水凝胶的溶胀度随着交联剂加量增加先增大后减小,在交联剂加量为0.5%时水凝胶溶胀度达到最大值。复合凝胶中的聚合物组成对溶胀度影响显著,随着P(AA-AM)含量提高,水凝胶的溶胀度逐渐增大。适当结构的复合水凝胶具有pH敏感性,敏感程度随着凝胶中P(AA-AM)含量的增加而增强。  相似文献   

18.
采用水溶液和水溶液胶束自由基聚合方法分别制备了聚N-异丙基丙烯酰胺水凝胶(PNIPA)和疏水改性PNIPA水凝胶:聚N-异丙基丙烯酰胺-co-丙烯酸甲酯(MA)/丙烯酸乙酯(EA)/丙烯酸丁酯(BA)/丙烯酸十二酯(DA)水凝胶。研究了凝胶的微观结构及不同结构的水凝胶在表面活性剂溶液中的溶胀行为。结果表明,PNIPA与疏水改性PNIPA水凝胶有着不同的微观形态结构;与PNIPA水凝胶相比,疏水改性PNIPA水凝胶在十二烷基硫酸钠(SDS)和十六烷基三甲溴化铵(CTAB)水溶液中的溶胀率增大,温敏性增强。疏水改性水凝胶在溶液中的溶胀行为与凝胶化学结构、溶液组成有关。对于疏水改性丙烯酸酯-NIPA共聚水凝胶,其溶胀率随丙烯酸酯碳链长度的增加而降低,在SDS溶液中的相转变温度远比CTAB溶液中的高,突变温度区间更宽。  相似文献   

19.
Organic-redox initiated polymerization technique based on the co-initiators system comprising benzoyl peroxide and N-phenyldiethanolamine was used at ambient temperature to fabricate pH-responsive hydrogels. The effects of changes in the concentration of the co-initiators system, the ratio in which the co-initiators combined, the type of the polymerization solvent, the pH of the hydrating medium, the concentration of the cross-linking agent based on azo-bond and the pH-sensitive cross-linking agent on the properties of the hydrogels were investigated. Increasing the concentration of the co-initiators system, decreasing the concentration of the two types of cross-linking agents, and replacing DMSO by ethanol as the polymerization solvent resulted in hydrogels with increased equilibrium swelling ratio and increased molecular weight between cross-links at pH 7.4. Increasing the concentration of N-phenyldiethanolamine while keeping the concentration of benzoyl peroxide constant gave hydrogels with increased equilibrium swelling ratios. The equilibrium swelling ratios of the hydrogels at pH 2.0 were not affected by the factors investigated. The polymerization technique may be suitable for the design of drug delivery systems containing thermolabile bioactive agents like peptides and proteins.  相似文献   

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