几种硅-硅链高聚物的合成和性质

采用具有不同取代基的二氯硅烷,在金属钠作用下共缩合的方法,合成了几种硅-硅链共聚物。这些共聚物分子量高,既能溶于一般的有机溶剂,也可在较低的温度下熔融,模压或浇铸成膜,或抽成纤维。在紫外光辐照下,高聚物的薄膜或纤维发生降解或交联反应。     

Organosilane polymers: Formable polymers containing reactive side groups

Formable organosilane polymers containing various reactive side groups were synthesized by hydrosilylation of unsaturated compounds containing reactive groups with poly(methylsilane) in the presence of platinum complexes. These polymers have appreciable solubility in common solvents, can be molded or cast into films or drawn into fibers, and are photoactive.     

电磷光发光聚合物*

电致磷光材料可以同时利用单线态和三线态激子发光,具有较高的发光效率,受到人们广泛的关注。本文综述了近年来通过共价键将磷光配合物单元连接在高分子链上制备电磷光发光聚合物的研究进展。总结了主链型、侧链型以及超支化结构的电磷光发光聚合物的研究进展,评述了上述几类电磷光聚合物的发光性能与分子结构的关系。最后从电磷光发光聚合物的分子结构设计出发,在电磷光发光聚合物领域业已取得进展的基础上,分析了电磷光发光聚合物在电致发光领域应用中存在的一些问题,并展望了电磷光聚合物今后的发展方向。     

Polymer Zwitterions for Stabilization of CsPbBr3 Perovskite Nanoparticles and Nanocomposite Films

Functional polymers with sulfobetaine or phosphorylcholine zwitterions as pendent groups are demonstrated as both ligands and host matrices for CsPbBr₃ perovskite nanoparticles (PNPs). These polymers produce nanocomposite films with excellent NP dispersion, optical transparency, and impressive resistance to NP degradation upon exposure to water. Multidentate interactions of the zwitterion‐containing copolymers with the PNPs induce dispersed or weakly aggregated nanocomposite morphologies, depending on the extent of zwitterionic functionality in the polymer. Incorporating additional functionality into the polymers, such as benzophenone pendent groups, yields lithographically patternable films, while time‐resolved photoluminescence measurements provide insight into the electronic impact of PNPs in zwitterionic polymer matrices.     

The Nano-threading of Polymers

When guest polymers are threaded by host cyclodextrins (CDs) to form crystalline inclusion compounds (ICs), the included polymer chains are highly extended and separated from neighboring chains. This is a consequence of the stacking of the cyclic oligosaccharides, α-, β-, or γ-CD containing 6, 7, or 8 glucose units, respectively, which produces continuous narrow channels (~0.5–1.0 nm diameters), where the guest polymers are included and confined. Observations that illuminate several important aspects of the nano-threading of polymers to form polymer-CD-ICs are described. These include (i) the competitive CD threading of polymers with different chemical structures and molecular weights from their solutions containing suspended solid or dissolved CDs, (ii) the threading and insertion of undiluted liquid polymers into solid CDs, and (iii) suspension of polymer A or B-CD-IC crystals in a solution of polymer B or A and observation of the transfer of polymer B or A from solution to displace polymer A or B and form polymer B or A-CD-ICs, without dissolution of the CD-ICs. In addition, we report observations of polyolefins adsorbed on zeolites, where we believe the adsorbed polyolefin chains are actually threaded and absorbed into the interiors of the zeolite nano-pores, rather than adsorbed on the zeolite surfaces. All of the above observations were made to assist in answering the question “Why do randomly-coiling polymer chains in solution or the melt become threaded or thread into the nano-pores of dissolved or solid CDs and solid zeolites, where they are highly extended and segregated from other polymer chains?” Though still not fully able to answer this question, we are able to assess the importance of several factors that have been previously suggested to be important in the formation of CD-ICs with both polymer and small-molecule guests and to the nano-threading of polymers in general. In particular, the value in observations of the inclusion of guest polymers, as well as small-molecule guests, into solid CDs suspended in their solutions and in neat guest liquids were made apparent, because interactions between host CDs, between CDs and solvents, and between quests and solvents, which complicate and make understanding the formation of polymer-CD-ICs difficult, are either eliminated or can be independently varied in these experiments.     

基于天然萜类的可持续性聚合物

随着可持续发展观念的逐步深入,可持续性聚合物已发展成为当今高分子领域的研究热点之一.萜类化合物作为自然界中一类来源广泛的天然资源,具有多种可修饰位点和丰富的功能性,由它出发制备可持续性聚合物,不仅可以简化聚合物的合成步骤,还可以赋予聚合物独特的立体构型、良好的生物活性和生物相容性等特点,进而拓展其在表面涂层、生物医药、组织工程等领域中的应用.本文综述了近年来国内外基于天然萜类可持续性聚合物的研究进展,从萜类化合物的结构特点出发,系统介绍了基于天然萜类可持续性聚合物的合成策略、特性及应用.     

Polymers containing anthraquinone units: Polyimidazoles and polypyrrolones from 1,2,5,6-tetraaminoanthraquinone

1,2,5,6-Tetraaminoanthraquinone has been condensed with isophthalaldehyde and terephthalaldehyde and their bisulfite addition compounds to yield new heat-stable polymers. It has also been condensed with pyromellitic anhydride to give the pyrrolone. The highest viscosities were obtained in polymers prepared with acid catalysts. The polymers were nearly all soluble in concentrated sulfuric acid but not in organic solvents. Those soluble in sulfuric acid could also be solubilized by reduction with sodium dithionite and potassium hydroxide in aqueous organic solutions. A few polymers were apparently crosslinked, since they would not dissolve in either sulfuric acid or in base on reduction. Weak fibers were obtained by spinning the reduced alkaline solutions of the polymers into aqueous acid.     

Post-functionalization of ATRP polymers using both thiol/ene and thiol/disulfide exchange chemistry

In this communication, we report on a new route to the functionalization of ATRP polymers exploiting their halide end-groups, which were converted successfully into reactive disulfide end-groups, using sodium methanethiosulfonate. The resultant disulfide-terminated polymers could then be reacted with different functional thiols to yield functional polymers exploiting either thiol/disulfide exchange chemistry or thiol/ene "click" reactions.     

Strain-induced fibrillation of glassy polymers

Literature data on structural rearrangements taking place in amorphous glassy polymers upon their plastic deformation are analyzed. This deformation is shown to be primarily accompanied by polymer self-dispersion into fibrillar aggregates composed of oriented macromolecules with a diameter of 1—10 nm. The above structural rearrangements proceed independently of the deformation mode of polymers (cold drawing, crazing, or shear banding of polymers under the conditions of uniaxial drawing or uniaxial compression). Principal characteristics of the formed fibrils and the conditions providing their development are considered. Information on the properties of the fibrillated glassy polymers is presented, and the pathways of their possible practical application are highlighted.     

ORGANOSILANE POLYMERS: SYNTHESIS AND CROSSLINKING OF FORMABLE POLYMERS CONTAINING PHENYLSILYLENE UNITS

Polysilane polymers which contain silicon hydride units in the chain were synthesized by sodium coupling of PhHSiCl_2 with R~1R~2SiCl_2 in toluene (R~1 and R~2 alkyl, aryl or aralkyl), followed by termination with a monochlorosilane and neutralization with sodium bicarbonate solution. These polymers are soluble in common solvents and can be formed into a variety of shapes by molding, casting, coating or potting. This class of polymers can be crosslinked by oxidation and irradiation, or by reaction with a multifunctional vinylsilane in th presence of platinum complexes.     

Regular Copolyamides. III. Preparation and Characterization of Regular Aliphatic/Aromatic Copolyoxamides

Regular aliphatic/aromatic copolyoxamides were prepared from diamine-oxamides and aromatic diacid chlorides by interfacial and solution polymerization. Solution polymerization in chloroform or dimethylacetamide is preferred for the preparation of large quantities of polymers but interfacial polymerization is most conveniently carried out for the preparation of polymers with high molecular weight. Aromatic diacid chlorides used included the diacid chlorides of terephthalic acid, isophthalic acid, 2,6-pyridinedicarboxylic acid, two isomeric naphthalene dicarboxylic acids, two cyclo-hexanedicarboxylic acid isomers, as well as 1,1-cyclobutane-dicarboxylic acid. Copolymers of diamine-oxamides with mixtures of acid chlorides of isophthalic and pyridine dicarboxylic acid and isophthalic acid/tetrachloroterephthalic acid have also been prepared. Most polymers are film-forming and are soluble in concentrated sulfuric acid, trifluoroacetic acid, and dimethylacetamide (containing several per cent LiCl). A number of these polymers gave dense or asymmetric membranes, particularly the polymers from ethylene diamine as the aliphatic diamine, particularly poly(iminoethyleneimino-oxalyliminoethyleneiminoisophthaloyl) (p-222I). Diamine oxamides with more than two amide groups in the molecules have been prepared, and in one case polymers with aromatic diacid chlorides have been prepared by interfacial polymerization. All regular aliphatic/aromatic copolyoxamides are high-melting and generally decompose above 350°C without melting. They can, however, be fabricated from solution into brittle fibers or into desalination membranes.     

Synthesis,characterization and application of soluble fullerenated polymer materials

This article only deals with the topic of intense interest to us and to a considerable extent of our own experimental results on the synthesis,characterization and application of C60-con-taining functional polymers such as poly(N-vinylcarbazole),polystyrene and polyacrylonitrile-based fullerene polymers.The results demonstrate that [60] fullerene can be directly incorporated into a variety of functional polymers by copolymer-ization or grafting,but also can be used to modify or improve the electronic,optical and physicochemical properties of polymers.Both the stereo-electroniceffect and the steric hindrance of C60 have an important influence on the structure and physicochemical properties of the parent polymer.     

Thiol‐Ene Step‐Growth as a Versatile Route to Functional Polymers

A new use of the thiol‐ene reaction to generate functional, redox‐tunable polymers is described. To illustrate the versatility of this approach, tailored divinyl ether monomers were polymerized with triethylene glycol dithiol to yield polymers containing either a carbonate or zwitterionic phosphocholine within the polymer backbone. Similarly, dithioerythritol was polymerized with triethylene glycol divinyl ether to yield a polymer with pendant diols and show how functional groups can be designed into either the divinyl ether or dithiol monomer. Using the thioether functional group inherent to this polymerization, all three polymers were selectively and quantitatively oxidized to either sulfoxides or sulfones by treatment with dilute hydrogen peroxide or mCPBA, respectively. With these illustrative examples, it is shown that the thiol‐ene polymerization is a broad‐reaching method to access a class of new redox‐active polymers which contain varied and dense functional‐group compositions.     

Creation of novel polymer materials by processing with inclusion compounds

The processing of polymer materials from their inclusion compounds (ICs) formed with urea (U) and cyclodextrin (CD) hosts is described. Several examples are presented and serve to demonstrate the fabrication of unique polymer‐polymer composites and blends, including intimate blends of normally incompatible polymers, and the delivery of additives to polymers by means of embedding polymer‐ or additive‐U and CD‐ ICs into carrier polymer films and fibers, followed by coalescence of the IC guest, or by coalescence of two polymers or a polymer and an additive from their common CD‐IC crystals.     

Optically active synthetic polymers as chiral stationary phases in HPLC

Synthetic, optically active polymers used as CSP are reviewed. The polymers are classified into three major categories, namely, addition polymers, condensation polymers, and cross-linked gels. The emphasis lies on polymethacrylates having helical conformation belonging to the first category. Helical polymethacrylates are synthesized using asymmetric anionic or radical polymerization techniques and show resolving ability towards a wide range of racemate.     

Syntheses and reactions of porphyrin and metalloporphyrin polymers

Various porphyrin functions such as protoporphyrin IX and chlorin a as well as metalloporphyrin functions such as Mg(II)– and Cu(II)–chlorophyllin a and Fe(III)– and Co(II)–protoporphyrin IX were incorporated into vinyl polymers by preparation and polymerization of their p-vinylbenzyl esters. The porphyrin function was also incorporated by reaction of poly-p-chloromethylstyrene with porphyrins or metalloporphyrins or by the reaction of p-aminostyrene polymers with chlorophyll b through Schiff-base formation. Mg(II)–porphyrin polymers were found to be remarkably effective as catalysts in photoredox systems; porphyrin polymers without central metal atoms were also effective to a lesser extent.     

含胆汁酸和胆固醇的双亲性聚合物的研究进展

胆固醇和胆汁酸是广泛存在于自然界中的天然物质 ,生物相容性好 ,被广泛地用于高分子的疏水性改性 ,得到的双亲性聚合物 ,在水相中可以自组装或自聚集成纳米粒子。本文综述了含胆固醇或胆汁酸的双亲性聚合物的最新研究进展以及它们在药物载体系统中的应用。     

Synthesis and liquid-crystalline behaviour of liposaccharide based comb polymers

In order to investigate the relationship between the liquid-crystalline state and the biological properties of polymers, we synthesized and studied liquid-crystalline comb polymers with a polyacrylamide main chain and three types of lipo-saccharidic side chains. These comb polymers were synthesized in four steps: first the polymerizable group was linked to the amino end of an α,ω-aliphatic amino acid; in the second step the ω-carboxylic acid function was activated in the form of an N-hydroxysuccinimidylester; in the third step the active ester was aminolysed by the amine function of the saccharide (N-methyl-D-glucamine, 2-amino-2-deoxy-β-D-glucose or 1-amino-1-deoxy-β-D-galactose) and a polymerizable liposaccharide was obtained; finally the liposaccharides were transformed into comb polymers by free-radical polymerization. Comb polymers exhibit mesophases in concentrated aqueous, ethanol or dimethylsulphoxide solution, and their mesomorphic character remains after the slow evaporation of the solvent. X-ray diffraction studies have shown that the mesophases have smectic or nematic ordering, depending upon the nature of the saccharidic residues of the liposaccharidic side chains.     

Synthesis of polymers by use of divalent metal salts of monohydroxyethyl phthalate: Metal-containing isocyanurate-type crosslinked polyurethanes

Divalent metal salts (I) of monohydroxyethyl phthalate have catalytic activity for polymerization of isocyanate groups. The synthesis of novel metal-containing isocyanurate-type crosslinked polyurethanes were investigated by the crosslinking reaction of I in DMF with diisocyanates or urethane prepolymers, that is, diisocyanate adducts of polyethylene glycol. 2,4-Toluene diisocyanate and diphenylmethane diisocyanate were used as diisocyanates, and DMF was the solvent. The crosslinking reactions were followed by determining the gelation time. Gelation time decreased with increasing temperature. The Ca salt was more effective than the Mg salt in the crosslinking reaction. The yields of resulting metal-containing three-dimensional polymers decreased with increasing metal content in the feed. The Ca salt was more easily introduced into the network polymers than the Mg salt was. Decomposition temperatures decreased on introducing metals into the network polymers. Some physical properties of the metal-containing network polymers are also discussed.     

Soluble narrow band gap and blue propylenedioxythiophene-cyanovinylene polymers as multifunctional materials for photovoltaic and electrochromic applications

A family of soluble narrow band gap donor-acceptor conjugated polymers based on dioxythiophenes and cyanovinylenes is reported. The polymers were synthesized using Knoevenagel polycondensation or Yamamoto coupling polymerizations to yield polymers with molecular weights on the order of 10 000-20 000 g/mol, which possess solubility in common organic solvents. Thin film optical measurements revealed narrow band gaps of 1.5-1.8 eV, which gives the polymers a strong overlap of the solar spectrum. The energetic positions of the band edges were determined by cyclic voltammetry and differential pulse voltammetry and demonstrate that the polymers are both air stable and show a strong propensity for photoinduced charge transfer to fullerene acceptors. Such measurements also suggest that the polymers can be both p- and n-type doped, which is supported by spectroelectrochemical results. These polymers have been investigated as electron donors in photovoltaic devices in combination with PCBM ([6,6]-phenyl C(61)-butyric acid methyl ester) as an electron acceptor based on the near ideal band structures designed into the polymers. Efficiencies as high as 0.2% (AM1.5) with short circuit current densities as high as 1.2-1.3 mA/cm(2) have been observed in polymer/PCBM (1:4 by weight) devices and external quantum efficiencies of more than 10% have been observed at wavelengths longer than 600 nm. The electrochromic properties of the narrow band gap polymers are also of interest as the polymers show three accessible color states changing from an absorptive blue or purple in the neutral state to a transmissive sky-blue or gray in the oxidized and reduced forms. The wide electrochemical range of electrochromic activity coupled with the strong observed changes in transmissivity between oxidation states makes these materials potentially interesting for application to electrochromic displays.