两亲聚合物/β-环糊精包合体系黏度调控方法

采用胶束聚合法合成两亲聚合物丙烯酰胺/十六烷基丙烯酰胺/丙烯酸钠三元共聚物。利用核磁共振氢谱对产物进行了表征。通过β-环糊精(β-CD)与两亲聚合物疏水基团之间的包合作用构建了黏度可调的主客体包合体系。通过旋转黏度计、电导率仪和原子力显微镜探讨了包合体系的黏度调控规律。结果表明,β-CD包合两亲聚合物疏水基团可降低两亲聚合物黏度并增强溶解性,十二烷基硫酸钠(SDS)通过竞争包合作用可部分恢复体系黏度。通过改变溶液中聚集体数量,可实现对主客体体系黏度的二次调控,但调控幅度减小。包合体系的黏度随温度、NaCl浓度和剪切速率的增加而降低;而包合作用随NaCl浓度增加而增强。     

阴离子长链疏水缔合水溶性聚合物的合成及溶液性能

利用溶液聚合制备了离子型疏水缔合水溶性共聚物P(AM/AMPS/C11AM),在共聚物结构中引入了既带有疏水长链又带有可离子化的基团,红外光谱确认了所合成的共聚物为目标共聚物;P(AM/AMPS/C11AM)系列共聚物溶液的表观黏度与共聚物浓度有很大关系,即使在极低的共聚物溶液浓度下也具有很好的增粘效果;在一定温度,一定pH值和表面活性剂的条件下,研究了系列共聚物溶液行为,结果与接枝疏水单体改性的丙烯酰胺是不同的。荧光光谱研究证实了共聚物在水溶液中的缔合行为。     

离子型表面活性剂与疏水缔合聚丙烯酰胺的相互作用

通过动态流变、幂律模型、动/静态激光光散射以及荧光光谱考察了丙烯酸十八酯(ODA)、丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)经超声辅助(Ultrasonic assist)自由基共聚制得的疏水缔合聚丙烯酰胺(UHAPAM)的动态流变性及其与阴阳离子型表面活性剂(十二烷基硫酸钠(SDS)和十六烷基三甲基溴化铵(CTAB))之间相互作用关系。结果表明,这种假塑性流体的临界聚集浓度(CAC)为0.27%。当UHAPAM水溶液浓度高于CAC时,SDS影响分子间疏水缔合,使水溶液表观粘度下降;CTAB反而改善疏水缔合性,使表观粘度明显增加,但增粘效果越来越缓和。表面活性剂均使溶液触变性降低。同时,形状因子(〈Rg〉/〈Rh〉)在SDS-UHAPAM体系里随SDS浓度的增加而增加,聚合物分子线团变得相对舒展;而在CTAB-UHAPAM体系里则随CTAB浓度增加而出现最低值,聚合物分子链段历经一个卷缩然后舒展的过程。在SDS和CTAB胶束中加入UHA-PAM,SDS聚集数先减小后增大,而CTAB聚集数则持续增加。     

疏水改性丙烯酰胺共聚物在水溶液中的缔合

罗丹明B荧光探针发现丙烯酰胺(AM)/丁基苯乙烯(BST)/2-甲基-2-丙烯酰胺基丙磺酸钠(NaAMPS)共聚物(PASA)在0.05 g/dL水溶液中疏水微区的黏度已较大,说明PASA具有强的疏水缔合效应。动态光散射结果表明,PASA在0.005 g/dL极稀溶液中,主要以单分子存在,部分单分子链发生了分子内缔合;在0.01 g/dL~0.2 g/dL范围内,溶液中均有构象伸展和卷曲的单分子存在,粒径有单分子区和疏水缔合区;当共聚物浓度增加为0.3 g/dL时,流体力学半径分布为单分散,只有缔合体存在。随着分子中疏水链段含量的增加,0.1 g/dL PASA溶液的疏水缔合体(Rh:2800 nm~5000 nm)的数量增加,溶液黏度显著升高。     

疏水改性聚丙烯酰胺P(AM/DiC_8AM)的合成及性能

采用二元单体胶束共聚,合成了孪尾疏水改性丙烯酰胺/N,N-二辛基丙烯酰二元共聚物[简称P(AM/DiC8AM)],成功引入了疏水单体.用FTIR分析了各基团峰的归属,证明了共聚物为带有疏水基团的二元共聚物.特性粘数的测定结果表明:分子量M、疏水单体含量[H]增加,特性粘数[η]增大,Huggins常数KH减少,平均线团密度ρequ减少;但随疏水链嵌段长度NH的增加,[η]们增大,KH同样增大.随疏水单体含量[H]、分子量M、疏水链的嵌段长度NH增加,各聚合物溶液临界缔合浓度cac降低,疏水缔合的机率增加.     

荧光探针研究温敏大分子单体在水溶液中的热缔合行为

通过芘荧光探针研究了基于双丙酮丙烯酰胺(DAAM)的新型温敏大分子单体在溶液中的热缔合行为。结果表明,温敏大分单体的临界缔合浓度(CAC)取决于丙烯酰胺(AM)与DAAM的组成比。DAAM的比例越大,CAC就越低;随着温敏大分子单体中DAAM的含量、大分子单体浓度和溶液pH的增加,芘的I1/I3值降低,疏水缔合作用增强,且温度越高,I1/I3值越低,呈现明显的热缔合行为。温敏大分单体的热缔合行为随组成、浓度和pH变化的这种性质有可能在新型温敏聚合物及凝胶的合成设计上获得应用。     

仿蝶翅超疏水涂层的制备研究

以丙烯酸六氟丁酯(HFBA)和含双键的硅树脂(SR)共聚合成疏水乳液,涂敷在棉织物表面上,然后再涂敷十六烷基二甲基苄基氯化铵(HDBAC)改性的蒙脱土(MMT),制备出超疏水涂层。对产物进行了XRD和扫描电镜分析,并考察了单体质量比、疏水乳液及MMT涂覆次数对棉织物疏水性能的影响。结果表明,制备的乳液-蒙脱土复合涂层在棉织物表面形成了类似蝶翅表面的微米-纳米二级结构。当单体SR与HFBA的质量比为5∶18,乳液和MMT分散液浸涂分别为3次和2次时,可使棉织物表面获得良好的超疏水性,接触角可达159.11°。     

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。     

羧甲基纤维素系列高分子表面活性剂在溶液中分子形态的研究

通过激光光散射和粘度法研究了羧甲基纤维素（ＣＭＣ）与烷基醇聚氧乙烯醚丙烯酸酯（ＡＲ１２ＥＯｎ）的超声共聚物在溶液中的分子形态。结果表明，随活性大单体支链增长，共聚物分子尺寸增大；水溶液中的胶束粒子随共聚物的疏水性增强而增大，ＣＭＣ－ＡＲ１２ＥＯ３体系胶束聚集数最大；共聚物分子与胶束均呈棒状结构。共聚物水溶液的粘度主要取决于分子量和胶束缔合数，盐水溶液中的粘度异常行为与共聚物中引入的大单体活性及形成的胶束结构有关。     

氟碳改性阳离子PAM的溶液性能与应用

以甲基丙烯酸十二氟庚酯(DFMA)为共聚单体,与丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)通过自由基胶束共聚法制得氟碳改性阳离子聚丙烯酰胺FPAD.研究了共聚物组成对FPAD溶液性能的影响,以及FPAD对造纸白水的絮凝效果.实验表明,FPAD水溶液中存在强烈的分子间缔合作用;当DFMA含量1.0 mol%、DMC含量15 mol%、引发剂用量0.03 mol%、表面活性剂与疏水单体的摩尔比值(SMR)20时,FPAD的特性黏数为677 mL/g,表现黏度达到18.0 mP·s以上;当添加量20mg/L、pH值6.0时,透光率可达99%.     

两亲聚合物溶液的流变规律及影响因素

针对大庆油田应用的两亲聚合物,通过扫描电镜揭示了其微观结构;利用MCR301流变仪测定了两亲聚合物的流变性,使用Carreau模型对流变曲线进行了拟合,确定了Na+、K+、S2-浓度越高,体系的黏度越低,η0越小;Ca2+、Mg2+浓度增加,η0先增加后降低。同时,研究了温度对两亲聚合物溶液黏度的影响,浓度低于临界聚集浓度(CAC)值时,浓度越高,两亲聚合物溶液的黏度对温度越敏感,而浓度高于CAC值后的规律则相反。因此,对于两亲聚合物驱,应选择浓度尽可能高于CAC值的体系。     

一种疏水缔合丙烯酰胺共聚物的合成及流变性能评价

采用自由基胶束共聚法以丙烯酰胺(AM)和N-苄基-N-辛基丙烯酰胺(BOAM)为原料,合成了疏水缔合共聚物(AM-NaA-BOAM),并用红外光谱(FT-IR)和核磁共振(1H-NMR)表征了共聚物的结构.溶液的流变性实验表明,当共聚物浓度大于600 mg/L时,表现黏度显著增大,表现出疏水缔合行为,溶液的储能模量(G...     

提高采收率用聚(N-羟甲基丙烯酰胺-丙烯酰胺)微球的反相微乳液聚合及其性能

以煤油为连续相,50.0wt%N-羟甲基丙烯酰胺(N-MAM)、丙烯酰胺(AM)单体水溶液为分散相,Span80/OP-10为乳化剂,依据拟三元相图配制了含50.6wt%油相、42.0wt%水相、7.4wt%Span80/OP-10(质量比6∶1)乳化剂相的W/O微乳液(质量分数)。以N,N-亚甲基双丙烯酰胺(MBAA)为交联剂,在65℃过硫酸铵(APS)引发下进行反相微乳液聚合制备了纳米级交联P(AM/NMAM)微球。以微球粒径及溶胀性为考察指标,从单体配比、交联剂用量、引发剂用量及搅拌速率等方面对合成条件进行了优化。结果表明,在单体配比m(AM)∶m(N-MAM)为4∶1,交联剂MBAA用量0.60wt%、引发剂APS用量0.50wt%(以单体总质量计)、搅拌速率1000r/min的条件下合成的微球耐盐性好、吸水倍率高,在1.0×10~5 mg/L模拟地层水中可达18.40g/g。扫描电子显微镜(SEM)、透射电子显微镜(TEM)对微球形态的表征结果显示,其具有较好的球形度及单分散性,粒径分布均一,约为100nm左右。流变及岩心封堵实验表明微球胶乳具有良好的注入性,封堵效果显著,可实现逐级深部调剖。     

Properties and influence of hydrophobically associating polyacrylamide modified with 2-phenoxylethylacrylate

The properties of hydrophobically associating copolymer P(acrylamide (AM)/2-phenoxylethylacrylate (POEA)), composed of acrylamide and a small amount of POEA (≤ 1.0 mol.%) as hydrophobe, were investigated in aqueous solution under various conditions. The results showed that the solution properties were strongly affected by the microstructure of copolymer. The copolymers (BP series) with hydrophobic microblocky structure exhibited large viscosity enhancement due to the inter-molecular hydrophobic association, while that did not occur for the random copolymers (RP series). The hydrophobic association thickening behaviors were also remarkably dependent on the number and length of the hydrophobic block in polymer chain. Nonlinear viscosity relationship was found as increasing hydrophobe content and SMR (surfactant/hydrophobic monomer molar ratio), and a maximum appeared at the middle position as a result of the competitive effect between inter- and intra- molecular hydrophobic associations. Solution properties were further studied as a function of the polymer concentration, salinity, temperature and shear rate. The block copolymers show high salt tolerance and shear thinning as well as recovery after shear.     

Properties and influence of hydrophobically associating polyacrylamide modified with 2-phenoxylethylacrylate

The properties of hydrophobically associating copolymer P(acrylamide (AM)/2-phenoxylethylacrylate (POEA)), composed of acrylamide and a small amount of POEA (⩽1.0 mol.%) as hydrophobe, were investigated in aqueous solution under various conditions. The results showed that the solution properties were strongly affected by the microstructure of copolymer. The copolymers (BP series) with hydrophobic microblocky structure exhibited large viscosity enhancement due to the intermolecular hydrophobic association, while that did not occur for the random copolymers (RP series). The hydrophobic association thickening behaviors were also remarkably dependent on the number and length of the hydrophobic block in polymer chain. Nonlinear viscosity relationship was found as increasing hydrophobe content and SMR (surfactant/hydrophobic monomer molar ratio), and a maximum appeared at the middle position as a result of the competitive effect between inter- and intra- molecular hydrophobic associations. Solution properties were further studied as a function of the polymer concentration, salinity, temperature and shear rate. The block copolymers show high salt tolerance and shear thinning as well as recovery after shear.     

活性可控自由基聚合法制备含纳米二氧化硅的星形丙烯酰胺共聚物

以单电子转移活性自由基聚合(SET-LRP)法,在水溶液中合成含纳米二氧化硅的新型星形水溶性共聚物,研究了单体、引发剂、催化剂、配体和改性纳米SiO2功能单体(NSFM)用量、单体摩尔比等条件对聚合反应的影响。采用红外光谱和核磁共振氢谱对制备的丙烯酰胺共聚物进行表征。结果表明,NSFM成功地参与了单电子转移活性自由基聚合反应中。通过正交试验确定了聚合反应的最佳物料摩尔比,即n(AM)∶n(AANa)∶n(Gly-Br3)∶n(CuBr)∶n(Me6TREN)=1687.5∶562.5∶1.0∶2.3∶1.5,[AM]+[AANa]+[NSFM]总浓度为4.5mol/L;单因素实验确定了NSFM的最佳用量为单体总质量的0.5%。用流变仪对共聚物的性能进行了研究。结果表明,当剪切速率超过临界值(100s-1)时,星形共聚物表现出剪切增稠的流变性能;P(AM-co-AANa-co-VTS-SiO2)表现出较好的耐温和抗盐性。     

甲基丙烯酸/衣康酸/烯丙基磺酸盐超分子分散剂的合成与性能表征

衣康酸(IA)、烯丙基磺酸钠(SAS)和甲基丙烯酸(ME)可通过自由基共聚反应制备具有两亲结构的水溶性超分子分散剂(SPMIS),文中通过对浆料的黏度、流变性进行表征得到了分散剂的最佳合成条件:单体配比为w(衣康酸)∶w(烯丙基磺酸钠)∶w(甲基丙烯酸)=1.0∶1.0∶1.3,反应温度为70℃。并对聚合物分散剂的结构和性质进行了分析,同时对粘土浆料的流变性和SEM图进行了研究,结果表明,分散剂中含有大量的-OH、-SO3H,当添加量为0.40%(相对绝干料的质量分数)时,分散效果最好。     

Pharmacodynamic and pharmacokinetic investigation of cyclodextrin-mediated asenapine maleate in situ nasal gel for improved bioavailability

Asenapine maleate (AM) is used in the treatment of schizophrenia. Its oral and sublingual bioavailability is <2% and 35%, respectively, due to first pass metabolism and poor solubility. To avoid first pass metabolism and to enhance solubility at all nasal pH conditions, thermo-responsive in situ nasal gel containing asenapine maleate-hydroxyl propyl β cyclodextrin inclusion complex (AM-HPβCD) was prepared in the present study. Inclusion complex (1:1 molar ratio) was characterized using UV spectroscopy, FITR and XRD techniques. Selected formulation (F8b) contained a thermo-sensitive polymer poloxamer 407 which formed gel at 23%w/v concentration and a mucoadhesive polymer PVP K 30 (0.3%w/v) in temperature range of 29–34?°c. It was analyzed for pH, clarity, gelation temperature, mucoadhesive strength, gel strength and rheological parameters using Anton paar compact rheometer. This formulation was subjected to in vitro drug diffusion study using the Franz diffusion cell. Maximum % drug diffusion was obtained at the end of 120?min (99.1?±?0.44%w/v). Dissolution in simulated nasal fluid was 92.33?±?0.15%w/v at the end of 120?min. Locomotor activity was improved with nasal gel containing AM-HPβCD as compared to AM and AM-HPβCD oral solution in rats. C_max for nasal gel was found to be more (9?ng/ml) as compared to AM-HPβCD (5.5?ng/mL) and oral standard solution (2?ng/ml). T_max was found to be 1.5?h. AUC and thus bioavailability in rats by nasal route was increased by 2.5 fold.     

Synthesis and characterization of biodegradable poly (ethylene glycol) and poly (caprolactone diol) end capped poly (propylene fumarate) cross linked amphiphilic hydrogel as tissue engineering scaffold material

Biodegradable poly (caprolactone diol-co-propylene fumarate-co-ethylene glycol) amphiphilic polymer with poly (ethylene glycol) and poly (caprolactone diol) chain ends (PCL-PPF-PEG) was prepared. PCL-PPF-PEG undergoes fast setting with acrylamide (aqueous solution) by free radical polymerization and produces a crosslinked hydrogel. The cross linked and freeze-dried amphiphilic material has porous and interconnected network. It undergoes higher degree of swelling and water absorption to form hydrogel with hydrophilic and hydrophobic domains at the surface and appreciable tensile strength. The present hydrogel is compatible with L929 fibroblast cells. PCL-PPF-PEG/acrylamide hydrogel is a candidate scaffold material for tissue engineering applications.     

二甲基二烯丙基氯化铵与丙烯酰胺的共聚动力学

采用膨胀计法研究了以过硫酸铵-亚硫酸氢钠为引发剂的二甲基二烯丙基氯化铵(DMDAAC)和丙烯酰胺(AM)的水溶液共聚合动力学,测定了相应的聚合速率方程、聚合表观活化能和单体竞聚率。结果表明,聚合反应温度为45℃,当DMDAAC与AM物质的量比分别为1∶9,2∶8和3∶7时,共聚速率方程分别为Rp1=k[M]2.61[IO]0.51[IR]0.52,Rp2=k[M]2.70[IO]0.50[IR]0.53和Rp3=k[M]2.73[IO]0.50[IR]0.56,表观活化能分别为Ea1=79.10 kJ/mol,Ea2=81.39 kJ/mol和Ea3=85.15 kJ/mol,两单体的竞聚率分别为rDMDAAC=0.14,rAM=6.11。上述实验结果可从动力学角度为不同阳离子度PDA聚合速率差别及产物特征黏度值差异进行解释。