含C60的苯乙烯和丙烯酰胺共聚物的合成与表征

在高分子领域中,C60的高分子化一直是C60材料化的一个重要途径.迄今为止,制备含C60高分子的方法有以下几种:(1)采用自由基引发剂、阴离子引发剂或阳离子引发剂引发C60与烯类单体共聚[1,2];(2)对C60进行表面修饰,引入可聚合官能团,合成含C60的单体,随后聚合成含C60的高分子[3];(3)制备出带有功能基团的高分子前体,再通过功能化反应将C60引入高分子链[4～9].     

C60与甲基丙烯酸甲酯共聚物的制备及光电导性能的研究

通过自由基聚合的方法制备了一系列甲基丙烯酸甲酯和C₆₀的共聚物,实验结果表明,增加引发剂的含量可以大大提高共聚物的产率。用元素分析、GPC和DSC等方法对共聚物进行表征。首次尝试研究了不含导电高分子的C₆₀共聚物体系的光电导性能,结果表明,该类共聚物光电导性能良好。     

NVC／BA共聚物的合成及其掺杂C60体系光电导性能研究

详细研究了Ｎ－乙烯基咔唑（ＮＶＣ）与丙类酸丁酯（ＢＡ）的共聚反应。用Ｆｉｎｅｍａｎ－Ｒｏｓｓ法测定了两种单体的竞聚率，发现两单体的竞聚率比较接近，可以进行较好的共聚合反应。通过ＴＥＭ观察，发现加入共聚单体ＢＡ可以大大改善聚乙烯基咔唑（ＰＶＫ）的成膜性能。     

C60与苯乙烯共聚物的制备及光电导性能的研究

通过自由基聚合的方法制备了一系列苯乙烯和Ｃ６０的共聚物。用ＴＧ＆ＤＴＡ,ＧＰＣ和ＤＳＣ等方法对共聚物进行了表征。首次在非共轭结构高分子共聚物体系上获得了光电导信号。光电导研究表明,该类共聚物具有良好光电导性能,并证明光电导来自Ｃ６０本身。     

Biodegradable and Electroactive TEMPO‐Substituted Acrylamide/Lactide Copolymers

Copolymers composed of PLA and PTAm were prepared by a macromonomer approach. The PLA bearing vinyl group at chain end was copolymerized with 2,2,6,6‐tetrametylpiperidine‐4‐ylacrylamide. The resulted copolymers were oxidized by a peroxide to give PTAm‐g‐PLA. The structures of the copolymers were confirmed by NMR and FTIR spectroscopy. The comparison of ¹H NMR results and SQUID measurements demonstrated that the oxidation of the PTAm fragment proceeded almost to completion. An MTT assay, cell adhesion and spreading evaluation showed that the copolymers exhibited improved cytocompatibility as compared to the PTAm homopolymer due to the introduction of the biocompatible PLA moiety.

     

Photoconductivity of C60‐doping benzocarbazole‐substituted polysiloxanes on an operating wavelength of 633 nm

A novel polysiloxane having benzo[a]carbazole, benzo[a,i]carbazole, and benzo[a,g]carbazole pendant groups has been synthesized and characterized. We studied the electric‐field‐induced xerographic properties, the photogeneration efficiency, and the photoconductivity of C₆₀‐doping polymeric composites at a wavelength of 633 nm. C₆₀‐doping with benzo[a,g]carbazole‐substituted polysiloxane shows a photogeneration efficiency of 56.55 × 10^?5 and a photoconductivity of 52.2 pS/cm at E = 100 V/µm, which was found to be higher than that of the other benzocarbazole‐substituted polysiloxane composites. Copyright © 2009 John Wiley & Sons, Ltd.     

裂解色谱法分析苯乙烯-丙烯酰胺共聚物

本文报道了用裂解色谱法分析一种新型的苯乙烯-丙烯酰胺共聚物的研究结果。考察了裂解温度、共聚物组成同主要裂解产物之间的相关性。提出了用相关曲线对不同类型共聚物的组成进行定量测定和鉴别的方法。讨论了由于分子链结构的差别导致无规和嵌段共聚物的不同的裂解行为。     

Synthesis and Characterization of Crystalline Styrene‐b‐(Ethylene‐co‐Butylene)‐b‐Styrene Triblock Copolymers

By merit of dual catalysis of the cationic rare‐earth complex [(η⁵‐Flu‐CH₂‐Py)Ho(CH₂SiMe₃)₂(THF) (Flu = fluorenyl, Py = pyridyl) for the living polymerizations of butadiene (BD) and styrene (St), the crystalline styrene‐butadiene‐styrene (SBS) triblock copolymers consisting of elastic polybutadiene (PBD) sequences with suitable 1,4 regularity (about 70%) and crystalline syndiotactic polystyrene (sPS, [rrrr] > 99%) sequences were successfully synthesized through sequential addition of St, BD, and St monomers. The catalytic system showed high polymerization activities for St and BD in a controlled manner. The crystalline styrene‐b‐(ethylene‐co‐butylene)‐b‐styrene (SEBS) triblock copolymers were obtained by hydrogenation of the above SBS copolymers. The observation of a strong endothermic peak at 266 °C in their differential scanning calorimetry (DSC) curves confirmed the existence of the sPS blocks in the crystalline SEBS different from the industrial product Kraton SEBS‐1652. Thermal degradation temperature of the crystalline SEBS (418 ± 2 °C) indicated the well thermostability and process window of this polymer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 55, 1243–1249     

Synthesis and Photophysical Properties of C60‐carbazole Adducts

Three C₆₀‐carbazole adducts have been synthesized by 1, 3‐dipolar cycloaddition reaction. Intramolecular energy/electron transfer from carbazole to C₆₀ was observed by steady‐state absorption and fluorescence spectra. The fluorescence spectra of these adducts were similar to each other and dependent on the excitation wavelength and solvent.     

Hybrids of Copolymers of Fluorene and C60‐Carrying‐Carbazole with Semiconducting Single‐Walled Carbon Nanotubes

Three different copolymers of C₆₀‐carrying‐carbazole and fluorene units with different copolymer composition ratios were designed and synthesized. On the basis of photoluminescence, atomic force microscopy, and Vis‐NIR and Raman spectroscopic analysis, we found that these copolymers solubilize only semiconducting single‐walled carbon nanotubes (sem‐SWNTs) to form copolymer/sem‐SWNT hybrids, in which energy transfer from the copolymer/C₆₀ moieties to the SWNTs was revealed. By comparing two possible hybrid structures with molecular‐mechanics simulations, the greatest stabilization was found when the C₆₀ moieties lay on the sem‐SWNT surfaces.     

Ln12‐Containing 60‐Tungstogermanates: Synthesis,Structure, Luminescence,and Magnetic Studies

A new class of hexameric Ln₁₂‐containing 60‐tungstogermanates, [Na(H₂O)₆?Eu₁₂(OH)₁₂(H₂O)₁₈Ge₂(GeW₁₀O₃₈)₆]^39? ( Eu₁₂ ), [Na(H₂O)₆?Gd₁₂(OH)₆(H₂O)₂₄Ge(GeW₁₀O₃₈)₆]^37? ( Gd₁₂ ), and [(H₂O)₆?Dy₁₂(H₂O)₂₄(GeW₁₀O₃₈)₆]^36? ( Dy₁₂ ), comprising six di‐Ln‐embedded {β(4,11)‐GeW₁₀} subunits was prepared by reaction of [α‐GeW₉O₃₄]^10? with Ln^III ions in weakly acidic (pH 5) aqueous medium. Depending on the size of the Ln^III ion, the assemblies feature selective capture of two (for Eu₁₂ ), one (for Gd₁₂ ), or zero (for Dy₁₂ ) extra Ge^IV ions. The selective encapsulation of a cationic sodium hexaaqua complex [Na(H₂O)₆]⁺ was observed for Eu₁₂ and Gd₁₂ , whereas Dy₁₂ incorporates a neutral, distorted‐octahedral (H₂O)₆ cluster. The three compounds were characterized by single‐crystal XRD, ESI‐MS, photoluminescence, and magnetic studies. Dy₁₂ was shown to be a single‐molecule magnet.     

疏水改性聚丙烯酰胺的合成

表面活性大单体;疏水改性聚丙烯酰胺的合成     

N‐Isopropylacrylamide Copolymers with Acrylamide and Methacrylamide Derivatives of Cholic Acid: Synthesis and Characterization

By free radical polymerization, we have prepared a series of water‐soluble, thermosensitive copolymers based on N‐isopropylacrylamide and (meth)acrylamide derivatives of cholic acid, one of the bile acids. The copolymers contained 1–7 mol‐% of the (meth)acrylamide derivatives of cholic acid. The chemical composition in the copolymers was studied by NMR spectroscopy and was found to be close to the original composition of the comonomers in the feed prior to polymerization. The lower critical solution temperatures (LCST) of the polymer solutions were measured by means of differential scanning calorimetry and turbidimetry. The resulting copolymers exhibit systematic changes in their LCSTs as a function of their chemical composition, as the incorporation of hydrophobic comonomers leads to a lower LCST.     

Effect of Cocatalyst in Ethylene/Styrene Copolymerization by Aryloxo‐Modified Half‐Titanocene–Cocatalyst Systems for Exclusive Synthesis of Copolymers at High Styrene Concentrations

Factors affecting the product distributions in ethylene/styrene copolymerizations catalyzed by Cp*TiCl₂(O‐2,6‐ⁱPr₂C₆H₃) are explored in the presence of various cocatalysts at high styrene/ethylene feed ratios (at 40 and 55 °C). Ethylene/styrene copolymers were the sole product when the reactions were conducted in the presence of [PhN(H)Me₂][B(C₆F₅)₄] and AlⁱBu₃/Al(octyl)₃ even at 55 and 70 °C, whereas syndiotactic polystyrene was by‐produced when the polymerizations were performed at >40 °C in the presence of MAO; the ratios of the copolymer/SPS were affected by the reaction temperature as well as Al cocatalyst employed.

     

Synthesis and Characterization of New Types of Perylene Bisimide‐Containing Conjugated Copolymers

Summary: Two new poly(perylene bisimide) polymers that contain biphenyl (PPery) and anthracene (PPeAn) groups at the bay position of perylene bisimide are designed and synthesized. The images of scanning and transmission electron microscopies for PPery and PPeAn show that both polymers form uniform nanoparticles. These copolymers emit red photoluminescence at around 640 nm with a relatively high photoluminescence quantum yield, 48% (in solution) for PPery and 68% (in solution) for PPeAn.

Structures of the new copolymers synthesized here: PPery and PPeAn.     

Styrene/1,3‐butadiene copolymerization by C2‐symmetric group 4 metallocenes based catalysts

C₂‐symmetric group 4 metallocenes based catalysts (rac‐[CH₂(3‐tert‐butyl‐1‐indenyl)₂]ZrCl₂ (1) , rac‐[CH₂(1‐indenyl)₂]ZrCl₂ (2) and rac‐[CH₂(3‐tert‐butyl‐1‐indenyl)₂]TiCl₂ (3) ) are able to copolymerize styrene and 1,3‐butadiene, to give products with high molecular weight. In agreement with symmetry properties of metallocene precatalysts, styrene homosequences are in isotactic arrangements. Full determination of microstructure of copolymers was obtained by ¹³C NMR and FTIR analysis and it reveals that insertion of butadiene on styrene chain‐end happens prevailingly with 1,4‐trans configuration. In the butadiene homosequences, using zirconocene‐based catalysts, the 1,4‐trans arrangement is favored over 1,4‐cis, but the latter is prevailing in the presence of titanocene (3) . Diad composition analysis of the copolymers makes possible to estimate the reactivity ratios of copolymerization: zirconocenes (1) and (2) produced copolymers having r₁ × r₂ = 0.5 and 3.0, respectively (where 1 refers to styrene and 2 to butadiene); while titanocene (3) gave tendencially blocky styrene–butadiene copolymers (r₁ × r₂ = 8.5). The copolymers do not exhibit crystallinity, even when they contain a high molar fraction of styrene. Probably, comonomer homosequences are too short to crystallize (n_s = 16, in the copolymer at highest styrene molar fraction). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1476–1487, 2008     

丙烯酰胺与丙烯酸十四酯共聚物的合成及性能研究

利用过氧化苯甲酰为引发剂探讨了丙烯酰胺（ＡＭ）和丙烯酸十四酯（ＴＡ）的自由基共聚合。重点讨论了合成条件如引发剂用量，单体配比、溶剂、温度等对共聚反应及共聚物对苯丙乳胶增稠性能的影响。并用ＩＲ和凯达定氮法表征了共聚物的组成，实验结果表明，ＡＭｔ ＴＡ进行沉淀聚合所得到的共物分子量足够大，可以作为疏水缔合型稠剂使用。     

含环糊精的温度敏感性聚合物的合成及自组装

合成了侧基含环糊精的聚异丙基丙烯酰胺(PnipamCD), 该聚合物在水溶液中具有较高的最低临界溶解温度(LCST). 快速升温到溶液的LCST以上可形成球形胶束, 慢速升温到LCST以上可形成空心囊泡. 在PNIPAM的选择性溶剂中, PnipamCD形成棒状组装体.