聚苯乙烯-b-聚2(5)-乙烯基对(间)苯二甲酸二钠嵌段共聚物的合成及其对PET结晶行为的影响

通过原子转移自由基聚合合成了线形及三臂聚苯乙烯-b-聚2(5)-乙烯基对(间)苯二甲酸二钠嵌段共聚物,通过凝胶渗透色谱、核磁共振和热失重表征证实得到了结构明确、分散度较窄的嵌段共聚物成核剂.采用熔融共混的方法制得聚对苯二甲酸乙二酯(PET)与成核剂共混样品.采用差示扫描量热仪与一维X射线衍射仪研究了PET及添加成核剂后...     

PLA-b-PEO-b-PLA三嵌段共聚物分子聚集体性质的研究

采用开环聚合的方法 ,合成了组成不同的PLA b PEO b PLA三嵌段共聚物 .滴加选择性溶剂水于共聚物的良溶剂溶液中 ,制备了共聚物以水为介质的“平头”聚集体胶束溶液 .把聚集体胶束溶液浇铸在云母片上 ,采用扫描探针显微镜 (SPM)表征了其形貌和表面微粘弹性 .发现脱离了极性介质水的聚集体的表面性质发生了不均一化 ,聚集体的顶部比相连接的部分具有较高的储能模量 .聚集体环境的改变使聚集体中不同嵌段的迁移导致了这种表面粘弹性的不均一 .另外 ,采用动态光散射的方法测量了体系溶液中聚集体胶束的尺寸 .实验发现光散射所得到的聚集体的尺寸远远大于SPM所得到尺寸 .增加聚合物的起始浓度使聚集体胶束的尺寸以及多分散性都在不同程度上增大 .然而聚合物的不同 ,这种增加的程度会有比较大的差别     

辐照三嵌段聚苯乙烯-丁二烯-4-乙烯基吡啶共聚物离子交换膜性能的研究——Ⅱ.共聚物膜的基本性能及分离实验

 本文研究了以辐照聚苯乙烯-丁二烯-4-乙烯基吡啶嵌段共聚物为膜基体所制成的嵌镶离子交换膜的基本性能.研究表明所制备的嵌镶膜在两端浓度分别为0.1及0.001 mol/L KCl 中的水渗析系数及电解质渗析系数分别是2.40×10^-5mol/cm²·min及2.10×10^-8mol/cm²·s.用所制备的嵌镶离子交换膜测试了牛血清白蛋白(M=67,000)与KCl混合溶液,蔗糖(M=343)与KCl混合溶液的膜分离效果.实验表明对上述两种非电解质均不能通过膜、而电解质KCl则可以.上述两种混合溶液中KCl渗透系数分别为J_KCl(牛血清白蛋白)=1.08×10^-8mol/cm²·s及J_(KCl)(蔗糖)=1.10×10^-8mol/cm²·s.     

ABA三嵌段离子型共聚物的合成及溶液自组装

以对二溴苄作引发剂,引发苯乙烯和甲基丙烯酸对硝基苯酚酯(NPMA)相继进行原子转移自由基聚合(ATRP),合成了3个三嵌段聚合物PNPMA-b-PS-b-PNPMA,其中聚苯乙烯段含有146个单元,PNPMA段的结构单元数分别为8、20和36.对这3个三嵌段共聚物分别进行水解反应及与2-氨基吡啶的取代反应,得到了具有相反电荷的PMAA-b-PS-b-PMAA和PNPMAAm-b-PS-b-PNPMAAm两种6个三嵌段共聚物.用核磁、红外和GPC表征了聚合物的结构、分子量及分子量分布等.将这两种三嵌段共聚物以等摩尔混合,在水中可自组装成碗形聚集体结构,讨论了可能的形成机理.     

两亲性ABA三嵌段共聚物的合成及其自组装行为研究

用Grubbs第二代催化剂引发降冰片烯类单体(NBEDE)和链转移剂在离子液体[bmim][BF4]中的开环易位聚合(ROMP)反应,反应体系保持均相,无聚合物析出,得到两端为叔溴的遥爪型官能化聚合物(Br-PNBEDE-Br).以Br-PNBEDE-Br作为大分子引发剂,在离子液体介质中引发甲基丙烯酸2-(二甲氨基)乙酯(DMAEMA)的原子转移自由基聚合(ATRP),制得分子量分布较窄的两亲性三嵌段共聚物(PDMAEMA-PNBEDE-PDMAEMA).利用动态激光光散射(DLS),原子力显微镜(AFM),透射电镜(TEM)等技术,考察嵌段共聚物在选择性溶剂/共溶剂(H2O/THF)中的胶束行为,以及溶液pH值对胶束的影响.结果表明,TEM观察到胶束为球形,由于TEM和AFM是在干态下测得胶束的粒径,而DLS是在溶液中测定胶束的流体力学直径,所以TEM和AFM得到的胶束粒径小于DLS的结果.不同pH值对胶束尺寸大小有明显的影响,胶束微粒随着pH值的增大而增大.     

HYDROLYSIS TRANSFORMATION OF A POLYSTYRENE—b—POLY（tert—BUTYL ACRYLATE） COPOLYMER AND MICELLIZATION PROPERTIES OF THE HYDROLYZED COPOLYMER

A very mild and extremely efficient hydrolysis method for transformation of polystyrene-b-poly(tert-butyl acrylate)(PS-b-PtBA)to polystyrene-b-poly(acrylic acid)(PS-b-PAA) was designed and carried out using more convenient and inexpensive chlorotrimethylsilane/sodium iodide as reagents.The hydrolysis product can self-assemble in aqueous media to give regular micelles with PS block forming the core and PAA block forming the corona,or in tetrahydrofuran (THF) to give reverse micelles with the hydrophilic block in the core.     

HYDROLYSIS TRANSFORMATION OF A POLYSTYRENE-b-POLY(tert-BUTYL ACRYLATE) COPOLYMER AND MICELLIZATION PROPERTIES OF THE HYDROLYZED COPOLYMER

1. INTRODUCTION The association of amphiphilic block copolymers has been the subject of numerous studies for several decades due to the academic interest and industrial applications [1~7]. It is well-known that block copolymers exhibit interesting domain structures in the solid state and form micelle-like aggregates in selective solvent [8]. They have found many potential applications in drug delivery [9], extraction of proteins [10], corrosion protection [11] as well as removal of aromat…     

辐照三嵌段聚苯乙烯-丁二烯-4-乙烯基吡啶共聚物离子交换膜性能的研究——Ⅱ.共聚物膜的基本性能及分离实验

本文研究了以辐照聚苯乙烯-丁二烯-4-乙烯基吡啶嵌段共聚物为膜基体所制成的嵌镶离子交换膜的基本性能.研究表明所制备的嵌镶膜在两端浓度分别为0.1及0.001 mol/L KCl 中的水渗析系数及电解质渗析系数分别是2.40×10~(-5)mol/cm~2·min及2.10×10~(-8)mol/cm~2·s.用所制备的嵌镶离子交换膜测试了牛血清白蛋白(M=67,000)与KCl混合溶液,蔗糖(M=343)与KCl混合溶液的膜分离效果.实验表明对上述两种非电解质均不能通过膜、而电解质KCl则可以.上述两种混合溶液中KCl渗透系数分别为J_(KCl)(牛血清白蛋白)=1.08×10~(-8)mol/cm~2·s及J_(KCl)(蔗糖)=1.10×10~(-8)mol/cm~2·s.     

Hybridization of poly(4-vinyl pyridine)-b-polystyrene-b-poly(4-vinyl pyridine) aggregates in dioxane/water solution

Self-assembly of binary blends of two triblock copolymers of poly(4-vinyl pyridine)-b-polystyrene-b-poly(4-vinyl pyridine), i.e., P4VP₄₃-b-PS₂₆₀-b-P4VP₄₃ (P1) and P4VP₄₃-b-PS₃₆₆-b-P4VP₄₃ (P2), in dioxane/water solution was studied. These two triblock copolymers individually tend to form vesicles (P2) and cylindrical micelles (P1) in dilute solution. It was found that copolymer components in the blend, sample preparation method, and annealing time had significant effect on hybridization aggregate morphology. By increasing P1 content in the copolymer blends, fraction of looped and stretched cylinders increased, while fraction of bilayers decreased. Nearly no bilayer was observed when P1 content was above 85 wt%. On the other hand, fraction of cylinders decreased while fraction of bilayers increased with the increase of P2 content in copolymer blends. Lamellar structures were obtained, when P2 content was 60 wt% in the copolymer blends, whereas cylinders were seldom found when P2 content was above 80 wt%. These results indicate that P1 and P2 copolymer molecules cooperatively participate in the formation of cylinders and vesicles. Some exotic structures, such as lamellae with protruding cylinders (LPC), incomplete vesicles with protruding cylinders (VPC), and cylindrical bilayers, have been kinetically trapped. These structures may result from intramicellar fusion processes in cylindrical micelles. The striking structures represent a compromise between bilayer and cylindrical geometries.     

MORPHOLOGICAL TRANSITION BETWEEN VESICLES AND TUBULES FOR A GLYCOPOLYMER-CONTAINING AMPHIPHILIC DIBLOCK COPOLYMER IN AQUEOUS SOLUTIONS*

The morphological transition of molecular assemblies in aqueous solutions for a new amphiphilic diblockcopolymer induced by changing the initial solvent conditions was studied by transmission electron microscopy (TEM). Thecopolymer was polystyrene(77)-b-poly [2 -(β-D-glucopyranosyloxy) ethyl acrylate (6)] (PSt_(77)-b-PGEA_6) and the solvent was amixture of DMF and THF. PSt_(77)-b-PGEA_6 yields vesicles and tubules when it is initially dissolved in THF and DMFrespectively. The morphological transition between vesicles and tubules can be achieved by simply varying the amounts ofTHF and DMF, or changing the temperature at which the aggregates were prepared.     

聚苯乙烯-b-聚氧乙烯-b-聚苯乙烯三嵌段共聚物的自组装

小分子表面活性剂、磷脂、接枝及嵌段共聚物等两亲分子在选择性介质中能够自组装形成特定的分子聚集体 [1,2 ] .嵌段共聚物自组装的某些行为具有生物膜模拟性 ,如最近发现的嵌段共聚物自组装囊泡 [3～ 5] .诸多因素影响着嵌段共聚物在稀溶液中的自组装行为 [6] .对于 ABA型三嵌     

含无规共聚组分的两嵌段聚合物A-b-(B-r-C)的合成以及自组装

通过原子转移自由基(ATRP)方法合成了其中一个嵌段是由2种单体无规共聚的两嵌段聚合物——聚丙烯酸肉桂酸乙酯-b-(聚苯乙烯-r-聚丙烯酸叔丁酯),(记为PCEA-b-(PtBA-r-PS)).讨论了聚合过程中影响分子量分布以及分子量控制的各种因素.通过氢核磁(1H-NMR)确定各嵌段的重复单元数分别为50,111,138.通过透射电镜(TEM)观察,研究了该嵌段聚合物在选择性溶剂1-氯癸烷以及环戊烷中的自组装行为,发现该嵌段聚合物在环己烷中直接分散可以形成有聚集倾向的短棒状或球形胶束,而在1-氯癸烷中直接分散得到的胶束,在膜表面随着1-氯癸烷溶剂的缓慢挥发可以组装得到具有规则微纳结构的相互连接的柱状胶束.     

辐照三嵌段聚苯乙烯-丁二烯-4-乙烯基吡啶共聚物离子交换膜性能的研究——Ⅰ.季铵化、磺化试剂、反应温度对膜性能的影响

 本文分别研究了以氯磺酸、浓硫酸为磺化试剂及一碘甲烷、二碘甲烷为季铵化试剂所制备的辐照聚笨乙烯-丁二烯-4-乙烯基吡啶离子交换膜的膜交换当量、吸水率,膜电位及膜电导率的性能。研究表明以氯磺酸为磺化试剂所制备的离子交换膜其离子交换当量比以浓硫酸寿磺化试剂的要高。以一碘甲烷为季铵化试剂制备的离子交换膜其离子交换当量要比以二碘甲烷为季铵化试剂的要高,但机械强度差。在相同条件下,提高反应温度,有利于膜的季铵化反应,而不利于膜的磺化反应。所制备的阴、阳离子交挟膜膜交换当量、膜电导率、吸水率及膜电位四者的关系是膜交换当量高则膜电导率、含水率高,而膜电位则下降。     

Studies of the end-capping of living anionic poly(ferrocenyldimethylsilane) with 1,1-diphenylethylene

The efficiency of capping poly(ferrocenyldimethylsilane) (PFDMS) with 1,1-diphenylethylene (DPE) at room temperature and at 50 °C is reported. The capping of living anionic PFDMS chains was investigated by synthesizing short PFDMS oligomers of 10 repeat monomer units for which the end groups can be probed by ¹H NMR. DPE is known to mediate the reactivity of the PFDMS, permitting the synthesis of block copolymers unobtainable by direct, sequential, living anionic polymerization such as poly(ferrocenyldimethylsilane)-block-poly(methylmethacrylate) (PFDMS-b-PMMA) and poly(ferrocenyldimethylsilane)-block-poly(2-vinylpyridine) (PFDMS-b-P2VP). However, at room temperature addition of the DPE is slow. We report that carrying out the capping of living PFDMS chains at elevated temperatures (50 °C) avoids the need to use a second reagent to facilitate the addition of DPE, or follow more complex synthetic routes.     

树枝状聚(醚-酰胺)基胶束的制备及其形貌研究

采用ε-己内酯(CL)开环聚合的方法首先合成树枝状聚(醚-酰胺)基(DPEA)星形聚合物star-PCL,再与异氰酸基封端的PEG(PEG-NCO)偶合制备了两亲性树枝状聚(醚-酰胺)基星形嵌段聚合物star-PCL-b-PEG.利用FT-IR、1H-NMR和GPC分析测试手段对star-PCL-b-PEG的结构进行了表征.通过滴加选择性溶剂的方法,制备了star-PCL-b-PEG以水为介质的类似"平头"聚集体胶束溶液.采用荧光光谱法测得star-PCL-b-PEG水溶液的临界胶束浓度(CMC)为1.623mg/L;采用激光光散射仪测得其在浓度0.15mg/mL和0.5mg/mL的流体力学半径分别为86.2nm和224.6nm,其多分散指数分别为0.115和0.197.透射电镜(TEM)观察发现胶束的形貌受共溶剂的特性,初始聚合物浓度,水含量等因素的影响.     

辐照三嵌段聚苯乙烯-丁二烯-4-乙烯基吡啶共聚物离子交换膜性能的研究——Ⅰ.季铵化、磺化试剂、反应温度对膜性能的影响

本文分别研究了以氯磺酸、浓硫酸为磺化试剂及一碘甲烷、二碘甲烷为季铵化试剂所制备的辐照聚笨乙烯-丁二烯-4-乙烯基吡啶离子交换膜的膜交换当量、吸水率,膜电位及膜电导率的性能。研究表明以氯磺酸为磺化试剂所制备的离子交换膜其离子交换当量比以浓硫酸寿磺化试剂的要高。以一碘甲烷为季铵化试剂制备的离子交换膜其离子交换当量要比以二碘甲烷为季铵化试剂的要高,但机械强度差。在相同条件下,提高反应温度,有利于膜的季铵化反应,而不利于膜的磺化反应。所制备的阴、阳离子交挟膜膜交换当量、膜电导率、吸水率及膜电位四者的关系是膜交换当量高则膜电导率、含水率高,而膜电位则下降。     

一种含有偶氮磺酸基与吡啶基的高分子氢键自组装及自组装超薄膜

静电自组装是指将带相反电荷的聚电解质，于水溶液中交替沉积在片基上，制备多层超薄膜的技术．由于它在水溶液进行，技术简单，无需专用设备，再加上静电力比范德华力强，因此静电自组装膜比传统的LB(Langmuir—Blodget)膜稳定，在近年来得到很大发展．现在自组装成膜驱动力已从最初的静电力扩展到氢键、电荷转移相互作用、疏水相互作用等；用于组装的组分也从聚电解质扩展到多官能团小分子、胶体粒子、无机纳米     

ATRP of 3-(triethoxysilyl)propyl methacrylate and preparation of “stable” gelable block copolymers

ATRP of a gelable monomer, 3-(triethoxysilyl)propyl methacrylate (TESPMA), mediated by CuBr/N,N,N’,N’’,N”-pentamethyldiethylenetriamine (PMDETA) using ethyl 2-bromoisobutyrate (2-EBiB) as initiator was studied. The results indicate that polymerization follows the first-order kinetic. PolyTESPMA (PTESPMA) is much more stable to moisture which is important for exploring the properties of its block copolymer. A series of PEO-b-PTESPMA block copolymers with different composition were prepared. Self-assembly of PEO-b-PTESPMA has also been explored in a mixture of methanol and water and polymeric vesicles have been obtained. By introducing the gelation catalyst, the block copolymer vesicles can be stabilized by the silica networks.     

蠕虫状聚离子复合型胶束的合成、组装和胶体稳定性

采用开环聚合方法制备了嵌段共聚物聚乙二醇-聚乙烯亚胺(PEG-b-PEI), 通过静电组装方法使其与质粒DNA(pDNA)在溶液中自发构筑成蠕虫状聚离子复合型胶束(PICmicelle), 利用原子力显微镜、 动态光散射、 Zeta电势和凝胶电泳等方法研究了血液或细胞间质中各种因素对胶束稳定性的影响. 结果表明, 在蠕虫状聚离子复合型胶束中, PEI和pDNA通过静电吸引构成疏水性内核, 而亲水性的PEG分子作为保护型外壳包裹在内核的表面. 在保持PEG链段长度不变的前提下, 增加PEI链段长度可明显增强PEI与pDNA的静电结合力, 有效地防止了NaCl对胶体结构的破坏, 而且有助于抑制阴离子的取代. 但增加PEI链段长度会导致胶束表面PEG分子含量的降低, 不利于胶束抵抗蛋白质的吸附和DNA酶的降解. 因此合理地调整PEG-b-PEI分子的结构, 对于获得高效、 安全和稳定的蠕虫状聚离子胶束具有重要意义.     

生物相容性BAB型两亲嵌段共聚物的合成及其自组装

Lys(z)-NCA was synthesized in the presence of triphosgene, amphiphilic triblock copolymers poly(N^c-CBZ-Lysine)-PEG-poly(N^c-CBZ-Lysine) were synthesized in DMF using amino-end ended PEG as initiator with the mechanism of anion ring opening polymerization. The structures of block copolymers were characterized by IR, ^1H-NMR,GPC and DSC. The results showed triblock copolymers with expected structure and low polydispersity in molecular weight could be synthesized by this method. At the same time, the self-assembling behaviors of block copolymer were investigated by TEM. A novel helical aggregates were found to be formed in DMF. Because of biocompatibility of two components of block copolymers, these block copolymers have potential applications in the field of biomaterials.