MOPc/DEH双组分单层结构有机光导器件的制作及其光电特性

制作了由金属酞菁、腙和高分子成膜剂组成的单层有机光导器件,测试了单层光导器件的光电性能参数,实验结果表明,这种单层光导器件对白光最敏感,可进行正负性充放电,有优异的光电性能.本文还探讨了MOPc/DEH双组分单层光导器件的电荷传输机理.     

高效光热转化发热聚酯纤维的制备与性能研究

采用熔融共混挤出,将高效率光热转化粉末材料碳化钛(TiC)均匀分散到聚酯中,再以制备的复合聚酯材料与聚酯进行共混、熔融纺丝,即制备得到不同比例的TiC的高效光热转化发热聚酯纤维。通过扫描电子显微镜、傅里叶红外光谱仪、NETZSCH热失重仪、红外测温仪等手段测试了所制备发热聚酯纤维的光热转化性能和发热性能。结果表明,含有0.5%碳化钛发热粉体的发热聚酯纤维在充分满足服用纤维机械强度标准的同时还可以很好地将温度控制在人体比较舒适的温度。     

海藻酸钠/水性聚氨酯共混膜的结构表征和性能测试

本文将海藻酸钠与聚酯型水性聚氨酯共混制膜，并通过红外光谱（FTIR）、X射线衍射（XRD）、扫描电镜（SEM）、紫外光谱（UV）、力学性能测试对共混膜的结构和性能进行了表征与测试。结果表明，共混膜中两种分子间存在着强烈的相互作用和良好的相容性，与纯海藻酸钠膜相比共混膜有较高的抗水性和断裂伸长率。     

热致液晶共聚酯／含酚酞侧基聚芳醚砜共混物的流变行为研究

采用溶液共混制备耻不同比例的热致液晶共聚酯／含酚酞侧基聚芳醚砜共混物。利用锥板流变仪对共混体系的熔体流变性能进行了初步研究，测定了熔体粘度－温度、粘度－剪切速度的关系，结果表明该液晶聚合物能明显降低聚芳醚砜的熔体粘度。     

聚合物在纳米半导体材料中的应用

半导体纳米材料在光、电、磁、催化等方面具有不同于本体的一系列特性。在纳米材料及其器件制备中，聚合物有着重要的应用。它不仅可以有效地稳定纳米晶粒尺寸，而且可以钝化表面，增强纳米微粒的发生效果。而纳米半导体对光导聚合物的光电行性也有增强作用。将电致发光聚合物与纳米半导体微粒组合而成双层异质结FL器件，可提高器件效率和寿命，甚至可以构成光导与电致发光双功能器件。     

两种不同晶型酞菁氧钒的制备及其光导性

以不同方法制备了两种不同晶型的酞菁氧钒（ＶＯＰｃ），Ｘ－射线分析结果表明，一为多晶型，另一种为非晶型。两种晶型在红外区都具有光导性，非晶型的光导性更好。     

单组分聚氨酯清漆的制备与性能研究

不同的聚碳酸酯二元醇、聚四亚甲基醚二醇(PTMG)与二苯甲烷二异氰酸酯(MDI)、小分子二元醇反应,制得聚醚、聚碳酸酯型聚氨酯清漆。通过红外光谱分析结合其机械力学性能、耐水性等的测试结果,探讨聚碳酸酯型聚氨酯清漆的结构对形态和性能的影响。结果表明：随着硬段含量的增加,树脂涂膜的微相分离程度增加,机械性能提高;组分摩尔比例相同时,软段分子量的降低有利于提高树脂的软硬段相容性,增加树脂涂膜的物理机械性能;组分摩尔比例相同时聚酯型聚氨酯树脂的微相分离程度低于聚醚型聚氨酯树脂;MDI基溶剂型聚氨酯树脂的物理机械性能较好。     

聚酯酰胺/淀粉接枝ε-己内酯/淀粉三元共混物的制备及相容性研究

制备了淀粉接枝ε－己内酯,以此作为相容剂与聚酯酰胺,淀粉进行三元共混,应用扫描电镜,电子能谐等分析手段讨论了共混物的制备及相容性变化。     

利用铁电薄膜研究体异质结型有机光伏器件的光电流极性

制备了铌镁酸铅-钛酸铅(PMN-PT)铁电薄膜,并通过紫外-可见(UV-Vis)透射光谱、X射线衍射(XRD)和原子力显微镜(AFM)对其进行了表征.为了研究体异质结型有机共混膜的光电流特性,制作了氧化铟锡(ITO)/PMN-PT/有机共混膜/铝(Al)的光伏器件,调制激光照射下外加偏压的极性和大小变化将直接改变瞬态光电流的极性和大小,从而可在实验上证明传统体异质结型有机光伏器件的光电流极性是由器件阴、阳电极的功函数差所导致的内建电场的方向决定.同时也提出了一种利用铁电薄膜来研究体异质结型有机光伏器件光电流特性的新方法.     

静电复印用双偶氮颜料的研究

合成了含邻氯双偶氮颜料,借助元素分析、红外光谱、吸收光谱、X射线粉末衍射等对其结构与性能进行了表征,并制成了功能分离型结构的有机光导器件。光电特性显示,该器件对可见光有很好的敏感性,是一种良好的静电复印用有机光导材料。     

Degradable polymer blends. I. Screening of miscible polymers

Blends of biodegradable polymers having properties distinct from the individual polymer components, and that are suitable for use as carriers of pharmaceutically active agents, were prepared from two or more polyanhydrides, polyesters, and mixtures of polyanhydrides and low molecular weight polyesters. The blends have different properties than the original polymers, providing a mean for altering the characteristics of the polymeric matrix without altering the chemical structure of the component polymers. Aliphatic, aromatic, and copolymers of polyanhydrides were miscible in each other and formed less crystalline compositions with a single melting point which was lower than the melting point of the starting polymers. The polyesters: poly(lactide-glycolide), poly(caprolactone), and poly(hydroxybutyric acid) presented some miscibility in each other. However, the polyanhydrides were immiscible with the polyesters resulting in a complete phase separation both in solution or in melt mixing. Only low molecular weight polyesters (in the range of 2000) of lactide and glycolide, mandelic acid, propylenefumarate, and caprolactone presented some miscibility with polyanhydrides. Similarly, poly(orthoester) and hydroxybutyric acid polymers formed a uniform mixture with the anhydride polymers which had the two melting points of the original polymers. Drug release from polymer blends composed of poly(hydroxybutyric acid) or low molecular weight poly(lactic acid) with poly(sebacic anhydride) (PSA) showed a constant release of drug for periods from 2 weeks to several months as a function of the PSA content in the blend. Increasing the content of PSA, a fast degrading polymer, increases the release rate from the blend. © 1993 John Wiley & Sons, Inc.     

Synthesis of hydrolytically degradable aromatic polyesters with lactide moieties

A synthetic route to higher molecular weight processable polyesters with bisphenol A terephthalate/isophthalate moieties and lactide moieties which are of potential interest for tissue engineering is described. The combination of aliphatic and aromatic moieties is a promising concept for processable polyesters with potential sites for physiological degradation and improved mechanical properties. The molecular structure of the copolyesters prepared by melt condensation via an acid chloride route and incorporation of the lactide moieties by transesterification of an oligo dl -lactide was confirmed by infrared, ¹H and ¹³C nuclear magnetic resonance spectroscopy as well as gel permeation chromatography. The thermal and mechanical properties of copolyesters with different amounts of lactide moieties are reported and correlated with their composition. The reaction mechanism by transesterification was proved by a model reaction with a physical blend of the components and the hydrolytical behavior of the copolyesters under physiological conditions has been investigated. © 1997 John Wiley & Sons, Ltd.     

新型功能性超支化聚酯的合成及表征

近年来 ,树枝状和超支化聚合物的研究受到了广泛重视 ,被视为 2 1世纪聚合物科学发展的重要方向[1] .这两种聚合物都有大量的端基 ,与相同分子量的线型聚合物相比 ,它们具有更低的粘度和更好的溶解性 .树枝状聚合物具有规整的结构 ,但合成困难 ;超支化聚合物的支化结构不完整 ,可以通过简单的一步聚合获得 ,因此 ,后者受到更广泛的重视 ,也最有可能实现工业化 [2 ,3] .通常 ,超支化聚合物是通过 ABx(x≥ 2 )型单体的缩聚合成的 ,通过改变超支化聚合物的组成、结构及对其端基进行功能修饰 ,可以制备多种具有特殊用途的新材料 ,在粘度改性剂…     

Solvent-stabilized oxovanadium phthalocyanine nanoparticles and their application in xerographic photoreceptors

A stable organic sol of solvent-stabilized oxovanadium phthalocynine (VOPc) nanoparticles with excellent photoconductivity was successfully prepared by ultrasonificating a prepared nanoscopic VOPc powder in1,2-dichloroethane (C(2)H(4)Cl(2)) without any additive. These solvent-stabilized VOPc nanoparticles have a size distribution from 2 to 20 nm with an average diameter of 4.6 nm. The VOPc concentration of these organic sols could be as high as 100 g/L. The nanoscopic VOPc particles were well-dispersed in an insulating polycarbonate (PC) resin, resulting in single-layered photoreceptors with high surface charge durability in the dark and excellent photoconductivity. Based on the light-assisted scanning tunneling microscopy (STM) measurements, the charge transport mechanism of these photoreceptors was ascribed to light-induced enhancement of electron tunneling through the VOPc-nanoparticle/insulator junctions.     

An excellent single-layered photoreceptor composed of oxotitanium phthalocyanine nanoparticles and an insulating resin

Photoconductive oxotitanium phthalocyanine (TiOPc) nanoparticles with an average diameter of 3.6 nm were successfully prepared. These nanoparticles could be well dispersed in organic solvents such as 1,2-dichloroethane to form a stable organic sol of solvent-stabilized TiOPc nanoparticles. An obvious size effect of TiOPc semiconductor was revealed by the UV-vis absorption spectroscopy measurements. Single-layered photoreceptors were prepared by coating colloidal solutions containing the C(2)H(4)Cl(2)-stabilized TiOPc nanoparticles and a polycarbonate (PC) resin onto aluminum plates. Optimum xerographic properties of the present photoreceptors were obtained on a photoreceptor containing 20 wt% of the TiOPc nanoparticles, which exhibited a photoconductive sensitivity (E(1/2)) of 0.54 microJ/cm(2) and could be positively charged to 596 V.     

Water absorption and degradation characteristics of chitosan-based polyesters and hydroxyapatite composites

Blends of chitosan and biodegradable synthetic aliphatic polyesters (polycaprolactone, poly(butylene succinate), poly[(butylene succinate)-co-adipate], poly[(butylene terephthalate)-co-adipate], and poly(lactic acid)) were injection-molded. These samples were immersed in isotonic solution at 37 degrees C for a period of 60 d. The water uptake and the degradation properties, as measured by the loss in tensile strength, were evaluated as a function of time. In this study, the rate and the equilibrium water uptake were proportional to the amount of chitosan in the blend. The addition of HA to chitosan and polyester significantly reduced the equilibrium water uptake. The water uptake did not follow the classical Fickian phenomena and could be expressed by a two-stage sorption non-Fickian diffusion model. Contact angle measurement was used to quantify the changes in surface hydrophilicity as a function of chitosan and polyester composition. The glycerol contact angle decreased with increasing synthetic components in the blend. The blends and composites also showed increased degradation, as quantified by a loss in their mechanical properties, with increase in natural content. The degradation of properties was directly related to the water uptake of the blends; the higher the water uptake, the higher the degradation. Pure polyesters, while having low water uptake, nevertheless showed significant degradation by a precipitous drop in the strain at break. Among the polyesters, poly(lactic acid) displayed maximum degradation, while polycaprolactone displayed the least.     

Phase separation two polymers in a blend and selective degradation as a method for porous structure formation

A method is proposed for the formation of porous structures in polymers. The method is based on the phase separation of two polymers in a blend and selective degradation of one of them. Polymers hydrolyzable at a high rate in alkaline media (polyesters of oxalic acid) are synthesized, and their hydrolytic degradation and phase separation in mixed solutions with a polylactide are investigated. Porous polylactide samples are prepared by the selective hydrolysis of polylactide-polyoxalate blends.     

Synthesis and characterization of aromatic polyesters with dicyanovinyl substituents

The synthesis, characterization, and structure—property relations of aromatic polyesters with dicyanovinyl substituents is presented. Two comparable series of polyesters based on 3,4-dihydroxybenzylidenemalononitrile and 3,4-dihydroxy-5-methoxybenzylidenemalononitrile were prepared. As aromatic diacid components, terephthalic acid, phenylterephthalic acid, isophthalic acid, and 2-phenylisophthalic acid were used. The polyesters were prepared by solution polycondensation. GPC investigations revealed the existence of substantial amounts of defined cyclic products. These cycles could be isolated by preparative GPC. The polyesters are soluble in common low boiling organic solvents, particularly the phenyl-substituted ones. The polyesters are amorphous and have glass transition temperatures between 140 and 170°C. The absorption maxima are in the 306–322 nm range. The cut-off wavelength is between 400 and 428 nm. The polyesters with methoxy substitutent have generally the absorptions at longer wavelength. The refractive index of thin films of these polyesters were between 1.61 and 1.63 at 632.8 nm. © 1993 John Wiley & Sons, Inc.     

A novel route for synthesizing esters and polyesters from the Diels-Alder adduct of levopimaric acid and acrylic acid

A novel route for the esterification of the Diels-Alder adduct between abietic acid, in its isomer form of levopimaric acid, and acrylic acid was established. The high purity Diels-Alder adduct was prepared starting from rosin acids. When the adduct was subjected to a condensation reaction in the presence of a cyclic carbonate ester and of an efficient amine catalyst, hydroxyalkyl esters were obtained. The corresponding linear polyesters were synthesized by the advanced polycondensation of the above intermediates at high temperature, under vacuum, and in the presence of some adequate polyesterification catalysts. In the work 1,3-dioxolan-2-one as cyclic carbonate ester, triethylamine as esterification catalyst, and toluene-4-sulfonic acid monohydrate or tetrabutyl titanate as polycondensation catalysts, were preferred for exemplifications. The polyesters were soluble in dimethylacetamide, trichloromethane, tetrahydrofuran, 1,1,2,2-tetrachloroethane, or 1,4-dioxane. The thermal and electric studies showed that the polymers were substances with good thermal stability and high dielectric properties.     

聚碳酸酯与苯乙烯-丙烯腈共聚物共混体系相容性及其对光学性能的影响

利用分子内链段排斥性相互作用理论研究了聚碳酸酯 (PC) 苯乙烯 丙烯腈共聚物 (SAN)共混体系中组份分子量及SAN共聚比例对体系相容性的影响规律 ,确定了获得均相的PC SAN共混体系的条件 ,考察了体系相容性与光学性能之间的关系 .通过实验获得了均相的PC SAN共混物 ;研究结果表明PC聚合度为 90、SAN聚合度为 3 0的PC SAN(S体积含量为 68%)体系共混比在 60∶40附近时体系的双折射能够实现补偿 ,紫外透光率达到 70 %.