星形含氟嵌段丙烯酸酯聚合物的合成及涂料性能

利用引发剂连续再生原子转移自由基聚合法(ICAR-ATRP)合成一系列结构及组成不同的聚(甲基丙烯酸丁酯-co-甲基丙烯酸缩水甘油酯)-b-聚甲基丙烯酸十二氟庚酯嵌段共聚物,并用于制备涂料。探索了聚合物星形结构和甲基丙烯酸缩水甘油酯(GMA)含量对聚合物性能和漆膜性能的影响。采用核磁共振氢谱、凝胶渗透色谱、差示扫描量热分析仪、接触角等方法对聚合物的结构及性能进行了表征。结果表明,同等化学组成下,星形含氟嵌段聚合物拥有比线型聚合物更低的玻璃化转变温度、黏度和更好的疏水性能。当聚合物GMA结构单元的质量分数为10%时,固化漆膜的水接触角达到112°,采用自制的脂环胺固化剂使得漆膜具有较好的耐紫外老化性能。     

基于双亲无规共聚物自组装胶体粒子的疏水涂层的构建及其性能研究

成功设计合成了一种含氟双亲性无规共聚物聚(苯乙烯-r-丙烯酸-r-甲基丙烯酸六氟丁酯)(PSAF),并在选择性溶剂N,N-二甲基甲酰胺(DMF)/水中自组装形成纳米粒子。结果表明自组装纳米粒子呈较为规则的球形,粒径约为114.1nm。在外电场的诱导下进一步将其二次组装在基材表面制备具有疏水性能的多孔涂层,利用扫描电子显微镜(SEM)、原子力显微镜(AFM)和视频光学接触角测量仪(OCA)对涂层的结构与性能进行表征,涂层的最大水接触角可以达到123.1°。     

分子结构对含氟丙烯酸酯嵌段聚合物/环氧树脂自分层涂料的影响

利用电子转移再生催化剂原子转移自由基聚合(ARGET-ATRP)合成了一系列不同共聚组成及相对分子质量的聚甲基丙烯酸丁酯-b-聚甲基丙烯酸十二氟庚酯(PBMA-b-PDFHMA)嵌段共聚物,并将其与环氧树脂E-20共用制备了混合涂料.基于各个组分及基材的表面能对混合涂料的分层行为进行了理论预测.通过傅里叶变换红外光谱、扫描电子显微镜证实了部分涂料在固化阶段发生了明显的分层行为.当相对分子质量较小时,含氟链段的含量对分层行为影响不大;当相对分子质量较大,含氟链段含量高时,自分层行为才容易发生.当合氟嵌段聚合物相对分子质量为1×104,含氟链段占嵌段共聚物质量的20％时,自分层涂料漆膜分层情况最好且水接触角达到108°.当含氟嵌段聚合物相对分子质量为3×104,含氟链段含量为20％时,其综合性能最优.     

一种嵌段聚羧酸减水剂的制备与表征

以CuCl、CuCl_2为催化剂,bipy为配体,2-溴丙酸甲酯为引发剂,通过原子转移自由基聚合的方法,采用二甲基亚砜(DMSO)和H_2O混合溶剂取代单一溶剂,合成了大分子引发剂POEGMA-Br;POEGMA-Br引发甲基丙烯酸叔丁酯聚合后水解,最终得到了PDI可控(PDI1.25)的嵌段聚羧酸POEGMA-b-PMAA。核磁共振氢谱与凝胶渗透色谱证明所得POEGMA-b-PMAA序列结构完全可控。将该嵌段聚羧酸用于水泥基材料分散,该聚合物能有效吸附于水泥颗粒上并减小团聚体尺寸,说明POEGMA-b-PMAA能分散水泥颗粒并改善水泥基材料的工作性。     

PBA-b-PHFBMA嵌段共聚物的制备及在涂料中的应用

利用原子转移自由基聚合(ATRP)法合成了丙烯酸丁酯-甲基丙烯酸六氟丁酯嵌段共聚物(PBA-b-PHFBMA),并以核磁共振谱和凝胶渗透色谱对共聚物进行了表征。将制备的含氟嵌段共聚物应用于丙烯酸酯涂料树脂,对其性能进行了研究。结果表明,在丙烯酸酯树脂中加入含氟嵌段共聚物后,树脂的表面性能及耐老化性能有了明显的提高。含氟嵌段共聚物的加入量在10%以上时,丙烯酸酯树脂的表面接触角可从73°提高到90°以上;经紫外光加速老化1700h后,树脂的保光率达90%以上。且含氟嵌段共聚物的加入并不影响丙烯酸酯树脂的其它漆膜性能。     

聚酯薄膜表面接枝含氟丙烯酸酯共聚物及其细菌粘附行为研究

利用表面引发原子转移自由基聚合(SI-ATRP)在聚对苯二甲酸乙二醇酯(PET)薄膜表面接枝甲基丙烯酸六氟丁酯(HFBMA)和甲基丙烯酸甲酯(MMA)共聚物。通过红外光谱仪(ATR-FT-IR),X射线光电子能谱仪(XPS)以及扫描电镜(SEM),研究不同反应时间下接枝共聚物对PET薄膜表面组成、结构及性能的影响;利用接触角测试对比研究PET薄膜接枝改性前后的表面疏水性;采用平板菌落计数的方法研究薄膜改性前后的微生物粘附性。结果表明:随着反应时间延长,PET薄膜表面水接触角不断增大,当反应时间为12h时达99.5°,疏水性显著提高;PET薄膜表面对微生物的粘附量随着反应时间的延长而逐渐减少。     

有机氟改性超支化水性聚氨酯的合成与性能

以异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)和二乙醇胺(DEOA)为原料,合成出了超支化聚氨酯核HBPU-0;以IPDI、聚醚多元醇(N220)、DMPA及甲基丙烯酸羟乙酯(HEMA)等原料合成带有双键的线型聚氨酯,然后将线型聚氨酯接枝到HBPU-0上,再与甲基丙烯酸六氟丁酯(HFMA)反应,制备了有机氟改性的超支化水性聚氨酯。通过红外光谱和核磁共振对聚合物进行表征,并研究了加入HEMA对乳液粒径、乳液的机械稳定性以及胶膜的力学性能、水接触角、吸水率和热性能的影响。测试结果表明,随着有机氟含量的增加,乳液水接触角和粒径增大,胶膜的拉伸强度升高,断裂伸长率下降,吸水率下降。加入有机氟后,胶膜耐热性有所提高,当有机氟含量为10%时,综合性能最佳,此时乳液粒径为145nm,胶膜的水接触角为93.4°,拉伸强度为11.7MPa,断裂伸长率为360%,48h吸水率为6.12%。     

全氟自交联型聚醋酸乙烯酯乳液的制备及其膜性能

以烯丙基嵌段聚醚(PAB)为反应型乳化剂,采用全氟烷基乙基丙烯酸酯单体(FEA)对其进行改性,并通过羟甲基丙烯酰胺(HMA)进行自交联,以醋酸乙烯酯(VAc)、丙烯酸丁酯(BA)、甲基丙烯酸(MAA)为主要单体,通过乳液聚合法制备了全氟自交联型聚醋酸乙烯酯乳液。同时考察了全氟单体对乳液的稳定性及涂膜的常规性能及耐水性、耐候性和耐蚀性的影响。研究结果表明,当氟单体含量为4.0%时,涂膜光泽度达84.5%,硬度2H,附着力1级,柔韧性1级,耐冲击性50cm,全氟自交联醋酸乙烯酯共聚物成膜时产生了较大取向作用,含氟基团向空气/聚合物界面伸展,对聚合物内部分子形成了很好的保护作用,故全氟自交联型聚醋酸乙烯酯膜具有良好的耐水性、耐候性和耐蚀性。     

共溶剂对丙烯酸酯聚合物/SiO_2杂化涂膜性能的影响

通过共混法制备丙烯酸酯聚合物/SiO2(PA/SiO2)杂化乳液,成膜过程添加醇类共溶剂促进偶联改性的聚合物与硅溶胶(SiO2)颗粒之间发生溶胶-凝胶反应。SEM图证实,无共溶剂的杂化涂膜SiO2颗粒趋于表面迁移及团聚,而异丙醇作共溶剂时SiO2颗粒在杂化涂膜表面均匀分散。成膜过程中添加15%异丙醇,杂化涂膜的耐化学品性和硬度等性能最佳。水接触角分析证实,添加共溶剂的杂化涂膜具有更好的耐水性能。AFM图表明,无共溶剂的杂化涂膜表面存在高度为217.9nm的团聚体;添加异丙醇的杂化涂膜表面粒子高度为65.97nm,略高于SiO2颗粒粒径,说明SiO2颗粒均匀分散在杂化涂膜表面。     

甲基丙烯酸环氧丙酯-b-甲基丙烯酸十二氟庚酯嵌段共聚物的合成及在疏水涂层中的应用

采用连续再生催化剂原子转移自由基聚合(ICAR ATRP)合成了甲基丙烯酸环氧丙酯-b-甲基丙烯酸十二氟庚酯嵌段共聚物(PGMA-b-PDFHMA)。然后将嵌段共聚物与纳米二氧化钛(Ti O2)复合制备疏水涂层。通过凝胶渗透色谱、核磁共振仪、接触角、扫描电子显微镜等对嵌段共聚物及涂层进行了研究与表征。研究结果表明,采用ICAR ATRP法成功制备了甲基丙烯酸环氧丙酯-b-甲基丙烯酸十二氟庚酯嵌段共聚物。嵌段共聚物结构及嵌段共聚物与纳米粒子的比例对涂层疏水性有显著影响。当含氟嵌段共聚物的链段摩尔比为1∶0.10,含氟嵌段共聚物与Ti O2质量比为0.5/1~10/1时,含氟嵌段共聚物接枝纳米Ti O2混合物制备的涂层表面的接触角可达150°。嵌段共聚物的含氟链段长度和涂层表面粗糙结构的差异是影响涂层疏水性的主要原因。     

含氟单体对阳离子氟碳无皂乳液性能的影响

采用有机助溶剂法,以甲基丙烯酸六氟丁酯(FA)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)、苯乙烯(St)、丙烯酸丁酯(BA)为反应单体,在N-甲基吡咯烷酮(NMP)作用下制备出阳离子氟碳丙烯酸酯共聚物无皂乳液(CFE)。通过凝聚率、沉淀量、动态激光光散射(DLS)、透射电镜(TEM)、接触角和吸水率等手段对CFE的稳定性、乳胶粒尺寸及形态、乳胶膜表面性能进行了表征。结果表明含氟单体用量增加,凝聚率明显提高,沉淀量略有下降;乳胶粒尺寸显著增加,粒径分布由单分散向多分散过渡;乳胶膜的表面性能大幅度提高,当m(FA)为20.14%时,吸水率和乳胶膜表面自由能可低至3.26%和21.11mJ/m2。     

Preparation and properties of an organic–inorganic hybrid materials based on fluorinated block copolymer

The block copolymers of poly 2,2,3,4,4,4-hexafluorobutyl methacrylate-block-poly[3-(trimethyoxysilyl)propyl methacrylate] (PHFMA-b-PTMSPMA) were synthesized via atom transfer radical polymerization and used for the preparation of organic/inorganic hybrid materials by the sol–gel approach. The polymers were characterized by gel permeation chromatography, Fourier transform infrared and ¹H nuclear magnetic resonance. The properties of the hybrid materials were investigated by Scanning electronic microscopy, contact angle, Scotch tape test, transmittances measurement, differential scanning calorimetry, and thermogravimetric analysis. The results were as follows: First, the hybrid materials had surface roughness, good hydrophobicity (>95° in contact angle with water), and could improve the contact angle of glass from 65.2° to 99.9° (the content of TMSPMA was 4.9 wt% in its polymer). Second, the adhesion of the hybrid materials to glass were enhanced by incorporating TMSPMA. Third, light transmittances of all the hybrid materials were above 90% in the visible range. Finally, the thermal stability of the hybrid materials were enhanced by incorporating silica moiety.     

Characterization of poly(L-lactide)-block-poly(ethylene oxide)-block-poly(L-lactide) triblock copolymer by liquid chromatography at the critical condition and by MALDI-TOF mass spectrometry

Poly(L-lactide)-block-poly(ethylene oxide)-block-poly(L-lactide) triblock copolymers (PLLA-b-PEO-b-PLLA) were fractionated in terms of the number of LLA units by liquid chromatography at the critical condition (LCCC) of PEO block. The fractionated samples were identified using MALDI-TOF mass spectrometry. The dependence of the LCCC retention of the diblock and triblock copolymers on the degree of polymerization of PLLA block(s) follows Martin's rule very well. Unlike the case of PEO-b-PLLA diblock copolymer reported earlier (Lee, H.; et al. Macromolecules 1999, 32, 4143), however, a splitting of the elution peaks containing the same number of LLA units was found. The peak splitting was ascribed to the different length distributions of PLLA blocks at the two ends of the PEO block. From the relative intensities of the peaks, the split peaks were assigned to different isomeric structures of the PLLA blocks. From these results we conclude that the interaction of the triblock copolymers with the stationary phase is affected by the distribution of the interacting blocks at the two ends of the center PEO block, in addition to the total number of LLA units in the triblock copolymer.     

Towards nanoporous membranes based on ABC triblock terpolymers

Block copolymers represent an exciting class of complex materials as they self-assemble into highly regular structures of nanoscopic dimensions. When prepared as thin films, such structures can be used for a variety of applications including lithographic masks or nanoporous membranes. Reported here are nanostructures in thin films of structurally analogous polybutadiene-block-poly(2-vinyl pyridine)-block-poly(tert-butyl methacrylate) (BVT) and polystyrene-block-poly(2-vinyl pyridine)-block-poly(tert-butyl methacrylate) (SVT) triblock terpolymers, which are synthesized via sequential living anionic polymerization. The morphological behavior of annealed SVT and BVT films is investigated by scanning force and electron microscopies. The difference in the terpolymer composition results in the formation of an ordered perforated lamella phase in SVT films and hexagonally packed core/shell cylinders in BVT films. Further, the BVT films show high potential for the fabrication of composite membranes using track-etched poly(ethylene terephthalate) macroporous filters as a support.     

两嵌段共聚物PMMA-b-PHEMA的合成与表征

采用分步法合成了两嵌段共聚物聚甲基丙烯酸甲酯-b-聚甲基丙烯酸-2-羟乙酯.首先以AIBN为引发剂,FeCl<,3>/PPh<,为>催化体系,通过甲基丙烯酸甲酯(MMA)的反向原子转移自由基聚合,得到端基含Cl的聚合物PMMA-Cl,其分子量分布为1.36;然后以此为大分子引发剂,FeCl<,2>/PPh<,3>为催化...     

聚离子复合物胶束的制备及其对辅酶A的控制释放

用RAFT活性可控聚合法合成了全水亲性嵌段共聚物聚(N-乙烯基吡咯烷酮)-b-聚(2-丙烯酰胺-2-甲基丙磺酸)(PVP-b-PAMPS)和聚(N-乙烯基吡咯烷酮)-b-聚甲基丙烯酸二甲氨基乙酯(PVP-b-PD-MAEMA).二者在水溶液中复合即可形成聚离子复合物(PIC)胶束,并利用动态光散射法(DLS)和透射电镜(TEM)表征了该胶束的粒径、粒径分布以及形貌.研究结果表明,所制备的胶束外形大致呈球状,粒径在155nm左右,且粒径分布较窄.以辅酶A为模型分子,负载在胶束内进行药物控制释放.研究结果表明,辅酶A的释放受溶液pH的影响,该聚离子复合物胶束可以用作药物控释载体.     

5-Fluorouracil-loaded PLA/PLGA PEG–PPG–PEG polymeric nanoparticles: formulation,in vitro characterization and cell culture studies

In this study, 5-FU, a potent anticancer drug, is planned to be delivered via a new and promising drug delivery system, nanoparticles formed with hydrophobic core polymer and triblock copolymers; Poly(DL-lactic acid), Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) copolymer (PLA/PEG-PPG-PEG) and Poly(D,L-lactide–co-glycolide)/Poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) copolymer (PLGA/PEG-PPG-PEG) nanoparticles. Particle size range of nanoparticles was found to be between 145 and 198?nm, which would promote the passive targeting of the nanoparticles to tumor cells based on the enhanced permeability and retention (EPR) effect. SEM images revealed all nanoparticles formulations to be spherical and without pores. Zeta potential, yield value and encapsulation efficiencies of 5-FU-loaded nanoparticles were within the range of ?11.1 and ?13.7?mV, 72.7–87.7% and 83.6–93.9%, respectively. Cumulative release of 5-FU was observed between 90% and 94.4% in all nanoparticle formulations by the end of 72?h, and fitness of release profiles to Higuchi model indicated matrix-controlled diffusion of the 5-FU from polymeric nanoparticles. Cell viability values of the cells treated with 5-FU-loaded nanoparticles were obtained as low as 47% and 52% with tetrazolium dye assay, suggesting that delivery of 5-FU via amphiphilic triblock copolymer nanoparticles would be a promising delivery system because of the EPR effect.     

SBP嵌段共聚物的合成和鉴定EI

用正丁基锂为引发剂,四氢呋喃为添加剂,按阴离子顺序加料方法合成了聚苯乙烯-丁二烯-4-乙烯吡啶(SBP)嵌段共聚物,经FTIR、UV、DSC、DDV等测试方法表征,证实了所合成的聚合物为聚苯乙烯-丁二烯-4-乙烯基吡啶嵌段共聚物。研究表明4-乙烯吡啶在聚合体系中聚合反应极为迅速且由于吡啶环上N原子对碳阴离子较为敏感,故嵌段共聚物中含有部分分子量较高的支化高分子。透射电镜表明样品具有精细的微相结构。聚合物的微相结构随聚合物中聚丁二烯含量提高,可以从蜂窝状结构转变成层状结构。     

Bioadhesion of various proteins on random,diblock and triblock copolymer surfaces and the effect of pH conditions

The adhesive interactions of block copolymers composed of poly(methyl methacrylate) (PMMA)/poly(acrylic acid) (PAA) and poly(methyl methacrylate)/poly(2-hydroxyethyl methacrylate) (PHEMA) with the proteins fibronectin, bovine serum albumin and collagen were studied by atomic force microscopy. Adhesion experiments were performed both at physiological pH and at a slightly more acidic condition (pH 6.2) to model polymer–protein interactions under inflammatory or infectious conditions. The PMMA/PAA block copolymers were found to be more sensitive to the buffer environment than PMMA/PHEMA owing to electrostatic interactions between the ionized acrylate groups and the proteins. It was found that random, diblock and triblock copolymers exhibit distinct adhesion profiles although their chemical compositions are identical. This implies that biomaterial nanomorphology can be used to control protein–polymer interactions and potentially cell adhesion.     

The use of force modulation microscopy to investigate block copolymer morphology

Force modulation microscopy (FMM) is used to characterize the external surface and internal fracture surface morphologies of three different block copolymer samples. A roll-cast poly(styrene-butadiene-styrene) triblock copolymer film, spin-coated poly(styrene-b-methyl methacrylate) thin films, and an ultrathin poly(styrene-b-hexyl isocyanate) rod-coil block copolymer film were investigated. For each sample, height and elasticity images were obtained for the same areas allowing direct comparison. The elasticity images obtained using force modulation microscopy were independent of surface roughness and found to exhibit better contrast and spatial resolution of the respective block copolymer domains than the height images. The lateral resolution of the elasticity images was sufficient to show microphase separated domains having length scales as small as about 10 nm. The poly(styrene-b-methyl methacrylate) samples demonstrate that FMM can even be successfully used to study block copolymers in which both blocks are glassy under the conditions of measurement.