CARBAZOLE-CONTAINING HYPERBRANCHED POLY（ARYLENEETHYNYLENE）S： SYNTHESIS, CHARACTERIZATION, AND PROPERTIES

New hyperbranched poly(aryleneethynylene)s containing carbazole moieties are synthesized in high yields(up to 87%)by polycyclotrimerization of 3,6-bis(4-ethynylphenyl)-9-octylcarbazole and its copolymerization with 1-octyne catalyzed by CpCo(CO)_2 in THF.The structures and properties of the polymers are characterized and evaluated by IR,NMR, TGA,UV,photoluminescence,and cyclic voltammetry analyses.All the polymers are soluble in common organic solvents and show outstanding thermal stability(≥430℃).They graphitize in high yields(up to 79%)when pyrolyzed at 800℃. Upon photoexcitation,the polymers emit a strong deep blue light of ca.400 nm with quantum yields larger than 60%.     

SYNTHESIS AND CHARACTERIZATION OF HYBRID PROTON CONDUCTING MEMBRANES OF POLY（VINYL ALCOHOL） AND PHOSPHOMOLYBDIC ACID

Hybrid proton conducting membranes of poly（vinyl alcohol） （PVA） and phosphomolybdic acid （PMA） were prepared by solution casting method. The effect of PMA doping and PVA crosslinking density on the membrane properties and proton conductivity were investigated. The crosslinking reaction between the hydroxyl group of PVA and the aldehyde group of glutaraldehyde （GA） was characterized by IR spectroscopy. Proton conductivity of the membranes increases with an increase in concentration of the doped PMA and also with an increase in crosslinking density of the membranes. Proton conductivity results indicate that a significant amount of PMA was maintained in the membranes even after several hours of immersion in water. A maximum conductivity of 0.0101 S cm^-1 was obtained for the membrane with 33.3 wt% PMA and crosslinking density of 5.825 mol%. X-ray diffraction studies were carried out to investigate the influence of PMA doping and crosslinking density on the nature of the membranes. These properties make them very good candidates for polymer electrolyte membranes for direct methanol fuel cell application.     

PREPARATION AND PROPERTIES OF POLY （LACTIC ACID-CO-GLYCOL TEREPHTHALIC ACID） COPOLYESTER

To obtain a kind of biodegradable polymer material with satisfactory properties, a new biodegradable copolyester poly(lactic acid-co-glycol terephthalate) (PETA), was synthesized from three monomers of lactic acid, glycol and terephthalic acid. The resulting copolyesters, PETA, were characterized by FT-IR, 1H-NMR, DSC, TGA and by the ways of weight loss rate to characterize their biodegradability. The findings in this work indicated that, the TmS and TdS of copolyesters PETA increased with increasing contents of the terephthalic acid units. From the biodegradation tests in natural soil, boiling water, acid buffer solution and alkali buffer solution, it was shown that the biodegradability of copolyesters PETA decreased with increasing contents of the terephthalic acid units.     

PREPARATION AND CHARACTERIZATION OF SHISH-KEBAB TYPE LIQUID CRYSTALLINE POLY（p-PHENYLENEVINYLENE）

Novel shish-kebab type liquid crystalline poly（p-phenylenevinylene） derivatives were synthesized by Stille coupling reaction from 2,5-bis[（4-n-alkoxyl）benzoyloxy]1,4-dibromobenzene （monomer l） and 1,2-bis（tributylstannyl） ethylene （monomer 2）. The polymers with alkoxy groups are soluble in common organic solvents and exhibit blue fluorescence. Both the cast film and the annealed film have large red-shifts in fluorescence spectra and show yellow fluorescence. The polymers with CN and NO2 groups show poor solubility and green fluorescence. All the polymers possess liquid crystalline smectic phases. The melting point （Tm） of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The polymers are easily aligned under a magnetic field of 10 Tesla. It is found that the conjugated backbone and LC side chain are aligned perpendicular and parallel to the magnetic field, respectively. The polymers show optical dichroism in fluorescence spectra, suggesting that they are available for advance materials with linear optical polarization.     

PREPARATION OF ACTIVATED CARBON FIBERS AND THEIR XENON ADSORPTION PROPERTIES（Ⅰ）-PREPARATION AND PORE STRUCTURE CHARACTERIZATION

A series of sisal based activated carbon fibers were preqared with steam activation at temperature from 750℃ to 900℃.Their pore structures were characterized through their nitrogen adsorption isotherms at 77K using different theories.The results showed that t-plot method and DR-plot method could suitably be used to characterize the mesopore structure and the multi-stage distribution of pore size of activated carbon fibers.It also showed that the pore size widens with the increase of activation temperature.     

CHARACTERIZATION OF NOVEL POLYMERIC INTERMEDIATE POLY（p-BROMOACETYL STYRENE） CROSSLINKED BY DIVINYLBEZENE

Acetyl crosslinked polystyrene (EPS) and crosslinked bromoacetyl polystyrene (BEPS)beads were synthesized by Fridel-Crafts acetylation of polystyrene (PS) and bromination of EPS respectively. FTIR, XPS, and TG-TDG were employed to characterize their structures. The results revealed there are two types of bromine in the BEPS molecule. One is in the main chain of polystyrene and the other is in the acetyl. The results of TG-DTG showed that the rates of loss weight of PS, EPS, and BEPS were 92.7%, 92.2%, and 81.3% among the 300 ℃～500 ℃; 7.3%, 7.8%, and 18. 7% in 594 ℃, 660 ℃, and 584.8 ℃, respectively.     

PREPARATION AND PROPERTIES OF CLAY/POLY（N-ISOPROPYLACRYLAMIDE-co-A CRYL AMIDE） NANOCOMPOSITE HYDROGELS

A series of clay/poly(N-isopropylacrylamide-co-acrylamide) nanocomposite hydrogels (S-N-M gels) have been successfully prepared by in situ polymerization. The mechanical properties,swelling behavior of S-N-M gels and the transparency changes during polymerization of S-N-M gels have been systematically investigated. Compared to traditional hydrogeb, S-N-M gels show excellent tensile properties and their swelling ratio increases with increasing acrylamide (AAm) content. The results of stress relaxation indicate that the stress loss decreases with increasing AAm content. It was surprisingly found that the transparency during all S-N-M gel synthesis changes abruptly, and the changes become more abrupt with increasing N-isopropylacrylamide content. It was concluded that the fact may be related to the hydrophilicity of copolymers. The weaker the hydrophilicity of copolymer, the more apparent the transparency change during S-N-M gels polymerization. We believe the relationship between hydrophilicity of copolymer and transparency changes will help to design novel nanocomposite hydrogels.     

NOVEL AMPHIPHILIC FLUORESCENT GRAFT COPOLYMER： SYNTHESIS, CHARACTERIZATION AND ENCAPSULATION OF A HYDROPHOBIC AGENT

Novel amphiphilic fluorescent graft copolymer （PVP-PyAHy） was successfully synthesized by the free radical copolymerization of hydrophobic monomer N-（1-pyrenebutyryl）-N＇-acryloyl hydrazide （PyAHy） with hydrophilic precursor polymers of vinyl-functionalized poly（N-vinylpyrrolidone） （PVP） in DMF. The copolymer is amphiphilic and has intrinsic fluorescence. FT-IR, ^1H-NMR, TEM, gel permeation chromatography-multi-angle laser light scattering, UV-Vis spectroscopy and fluorescence spectroscopy were used to characterize this copolymer. The TEM observation shows that the copolymer PVP-PyAHy forms micelles in aqueous solution. Results of fluorometric measurements illustrate that the critical micelle concentration （CMC） value of PVP-PyAHy in aqueous solution is about 0.90 mg/mL. To examine the encapsulation ability of the copolymer in aqueous media, methyl yellow was employed as a model hydrophobic agent. The loading level of the polymer to methyl yellow is 8.8 mg/g. The cytotoxicity assays for Madin Darby Canine Kidney （MDCK） cells shows good biocompatibility of PVP-PyAHy in vitro. These results suggest the potential of this copolymer PVP-PyAHy as drugs delivery carrier and fluorescent tracer.     

SYNTHESIS, HELICITY, AND BIOLOGICAL PROPERTIES OF MONOSACCHARIDE-CONTAINING POLY（PHENYLACETYLENE）S

Poly（phenylacetylene）s beating monosaccharide pendant groups are synthesized in high yields by [Rh（nbd）Cl]2 catalyst. The polymers have high molecular weights and give satisfactory spectroscopic data corresponding to their molecular structures. They are thermally quite stable （≥ 300℃） and show strong circular dichroism signals in the visible spectral region owing to the helicity of the polyene backbone. The monosaccharide-containing polyacetylenes are cytophilic and can stimulate the growth of living cells.     

PREPARATION AND CHARACTERIZATION OF INCLUSION COMPLEXES OF TWO-ARM LINEAR AND FOUR-ARM STAR-SHAPED POLY（ε-CAPROLACTONE）S WITH α-CYCLODEXTRIN

Both four-ann star-shaped poly（ε-caprolactone） （4sPCL） and two-ann linear PCL （2LPCL） were synthesized and their inclusion complexation with α-cyclodextrin （α-CD） were studied. The inclusion complexes （ICs） formed between the PCL polymers and α-CD were characterized by ^1H-NMR, DSC, TGA, WAXD, and FT-1R, respectively. Both branch ann number and molecular weight of the PCL polymers have apparent effect on the stoichiometry （CL：CD, mol：mol） of these ICs. All these analytical results indicate that the branch arms of the PCL polymers are incorporated into the hydrophobic α-CD cavities and their original crystalline properties are completely suppressed. Moreover, the inclusion complexation between two-ann linear or four-ann star-shaped PCL polymers and α-CD not only enhances the thermal stability of the guest PCL polymers but also improves that of α-CD.     

超支化聚(胺酯)的分子设计及其制备

以丙烯酸甲酯和二乙醇胺为原料由Michael加成反应制得N ,N 二羟乙基 3 胺基丙酸甲酯单体 ,再用“准一步法”和“发散法”使之与 1 ,1 ,1 三羟甲基丙烷 (核 )反应合成一种新型超支化聚 (胺 酯 ) .以核磁共振和元素分析方法对N ,N 二羟乙基 3 胺基丙酸甲酯单体的分子结构进行了表征 .GPC测定表明合成的超支化聚 (胺 酯 )分子量分布窄 ,具有单分散性 ;粘度小于同分子量的线形分子 ;耐热性能较好 ,失重温度高于2 0 0℃ .     

STUDY OF NANOSIZED SILICA GRAFIED WITH HYPERBRANCHED POLY（AMINE-ESTER）

A new method to chemically modify the surface of nanosized-SiO2 was studied in this paper. Nanosized-SiO2 was grafted with hyperbranched poly(amin ester) through one-spot polycondensation between AB2 monomer and active hydroxyl on silica surface in present of catalyst.Compared with the results of FTIR and TEM, it is found hyperbranched poly(amin ester) is successfully grafted on the surface of nanosized-SiO2 and the surface properties have been changed with an expected way. The results indicate that nanosized-SiO2 grafted with hyperbranched poly(amin ester) has better dispersion in the ethanol or chloroform than that unmodified.     

STUDY OF NANOSIZED SILICA GRAFIED WITH HYPERBRANCHED POLY(AMINE-ESTER)

1. INTRODUCTIONIn order to solve the agglomeration of nano-SiO2 and improve its dispersion stability in polymer matrix, the study on surface modification of nano-SiO2 has been always attended. At present, surface modification of nano-SiO2 is mostly carrie…     

超支化聚硅氧基硅烷的合成及其表征

基于线性聚硅氧烷在国防、能源和化工等领域的广泛应用,具有新颖拓扑结构和大量功能性端基的超支化聚硅氧烷引起了国内外科学工作者的广泛兴趣[1~7].到目前为止,主要是采用水解缩聚的方法合成超支化单体,在铂系催化剂存在下进行硅氢加成反应或者在碱催化剂存在下进行质子转移聚合制备超支化聚合物[8~12].然而,以上合成超支化聚硅氧烷的方法仍然存在一定的不足.例如,水解法步骤繁琐,通常在第一步反应结束后需要多次除水,并继续滴加单氯硅烷以得到完全取代的大单体;同时多官能度单体容易水解自缩聚,产生A2B4或A3B6等副产物,不仅不利于结构控…     

可光固化超支化聚硅氧基硅烷的合成与表征

自20世纪80年代末期Kim和Webster首次采用AB2型单体合成超支化聚合物以来，超支化聚合物以其新颖的结构、独特的性能和广泛的应用前景受到了科学界和工业界的广泛关注．其中超支化有机硅聚合物，尤其是硅氧基聚合物，由于具有良好的高低温稳定性、耐腐蚀性、耐候性等，以及硅氯、硅氢等末端基团易于功能化改性的特点，使其在功能性涂层材料、催化剂以及液晶材料等领域具有重要的应用价值．到目前为止，有关超支化聚硅氧基硅烷的研究主要集中在AB2型单体（x≥2，A和B分别为硅氢基团和乙烯基、烯丙基等不饱和基团）的制备以及硅氢加成产物的功能化改性方面．     

SYNTHESIS AND CHARACTERIZATION OF HYPERBRANCHED POLY(ESTER-AMIDE)S BASED ON GALLIC ACID AND DL-2-AMINOBUTYRIC ACID

INTRODUCTIONHighly branched macromolecules including dendrimers and hyperbranched polymers are interesting materialswith unique molecular structures and potential applications[1-5]. The two types of polymers have many analogousphysical and chemical properties such as high solubility, low viscosity and abundance of terminal groups. Theformer attracts much attention of researchers due to its perfect monodisperse architecture, but its preparation isgenerally tedious because of various protect…     

可自交联超支化聚醚醚酮的合成与热性能研究

近15年来,由于超支化聚合物所具有的三维椭球状结构,良好的溶解性,大量末端官能团等独特的物理、化学特性及其在涂料、添加剂、药物载体、基因载体、大分子建筑“砌块”、超分子科学等领域的潜在应用,已成为高分子研究领域的一个热点．超支化聚合物在光通讯及微电子等领域的应用也已引起人们广泛而高度的重视．聚合物具有良好的热稳定性及溶解性是作为微电子和光学集成线路所必需的．本文以含有大侧基的“功能性”A：单体2．（4-苯氧基苯基）．1,4．苯二酚（POP）与B单体1,3,5-三[（4．（4．氟苯酰基）苯氧基]苯进行缩聚反应,得到全芳结构超支化聚醚醚酮（HPOP-PEEK）．     

超支化聚(胺酯)的合成及其光固化性能研究

采用甲基丙烯酸酐直接改性和先以丁二酸酐或邻苯二甲酸酐酯化再以甲基丙烯酸缩水甘油酯改性所得到的甲基丙烯酸酯化超支化聚 (胺 酯 )齐聚物在光引发剂存在时紫外光辐照下发生快速聚合反应 ;反应速率和双键转化率随超支化分子的结构不同而变化 ;高度交联的涂膜具有较好的热学性能     

超支化聚酯低压纳滤膜的制备与表征

通过超支化聚酯(HPE)末端的羟基与戊二醛(GA)之间的羟醛缩合反应,采用简单的浸涂-交联方法,制备了一种以聚砜超滤膜为支撑层,交联的HPE为活性分离层的复合纳滤膜.采用衰减全反射红外光谱(ATR-FTIR)、接触角测定、扫描电子显微镜(SEM)对纳滤膜的表面化学组成、亲水性和膜形貌进行了表征.考察了HPE溶液浓度、GA溶液浓度对膜分离和渗透性能的影响,优化的HPE和GA溶液浓度分别为9.8 g/L和7.4 g/L,此时在0.4 MPa下膜的水通量达69.6 L/(m2.h),对Na2SO4脱除率为93.2%,表现出低操作压力、高通量、高脱盐率的优异性能.纳滤膜对无机盐的截留顺序为Na2SO4>NaCl>MgSO4>MgCl2,呈现明显的荷负电特征.