聚氧化乙烯与聚乙烯醇共混体系的研究

采用水溶液共混法制备共混物，研究了聚氧化乙烯与聚乙烯醇共混体系的相容性及共混体系中各组分的结晶性。实验结果表明，ＰＥＯ／ＰＶＡ共混物为不相容共混体系。ＰＶＡ分子间易于形成氢键是此共混体系不相容的主要原因。ＰＥＯ／ＰＶＡ共混体系为相分离结构，ＰＥＯ及ＰＶＡ皆可在各自的相区内形成结晶。体系中ＰＶＡ的存在不影响ＰＥＯ的结晶能力，共混体系在组成为５０／５０左右其力学性能有急剧变化，提示在此时发生了相倒转。     

PVC／CEVA共混体系相容性研究

采用ＤＳＣ对ＰＶＣ／ＣＥＶＡ溶液共混物的玻璃化转变进行了研究。结果表明，对ＣＥＶＡ／ＰＶＣ质量比分别为１：９、２：８、４：６、８：２的共混体系，各共混物均分别出现一个明显的玻璃化转变温度，表明ＶＡｃ质量含量为５．９％，但氯含量为５８％的ＣＥＶＡ与ＰＶＣ具有较好的相容性，这是ＣＲ－ＭＭＡ－ＣＥＶＡ接枝共聚物对增塑ＰＶＣ人造革显示出较高粘合性能的主要根源。     

HPVC／PP共混改性研究：IV共混物的流变特性

研究了ＨＰＶＣ／ＰＰ共混物的流变性能，结果表明，ＣＰＥ，ＡＢＳ对ＨＰＶＣ／ＰＰ有增粘作用，随着ＣＰＥ用量增加，共混物熔体粘度（η）增加。ＣＰＥ或ＡＢＳ先与ＨＰＶＣ共混后再与ＰＰ共混的共的的η高于ＣＰＥ或ＡＢＳ先与ＰＰ共混后再与ＨＰＶＣ共混的共混物ηＨＰＶＣ／ＰＰ，ＨＰＶＣ／ＰＰ／ＭＡＨ２．５ＨＰＶＣ／ＰＰ／ＣＰＥ１０，ＨＰＶＣ／ＡＢＳ１０共混物的η～组成（Ｃ）的关系均属于正－负偏离共混物（Ｐ－ＮＤ     

HPVC/PP共混改性研究Ⅳ共混物的流变特性

研究了ＨＰＶＣ／ＰＰ共混物的流变性能，结果表明，ＣＰＥ、ＡＢＳ对ＨＰＶＣ／ＰＰ有增粘作用。随着ＣＰＥ用量增加，共混物熔体粘度（ηａ）增加。ＣＰＥ或ＡＢＳ先与ＨＰＶＣ共混后再与ＰＰ共混的共混物的ηａ高于ＣＰＥ或ＡＢＳ先与ＰＰ共混后再与ＨＰＶＣ共混的共混物的ηａ。ＨＰＶＣ／ＰＰ、ＨＰＶＣ／ＰＰ／ＭＡＨ２．５、ＨＰＶＣ／ＰＰ／ＣＰＥ１０、ＨＰＶＣ／ＰＰ／ＡＢＳ１０共混物的ηａ～组成（Ｃ）的关系均属于正－负偏离共混物（Ｐ－ＮＤＢ）体系，即在特定共混比下发生相转变。     

聚氯乙烯／聚丙撑碳酸酯共混相容性研究

分别用溶液法和熔融法制得聚氯乙烯（ＰＶＣ）与聚丙碳酸酯（ＰＰＣ）共混试样，用ＤＳＣ证明ＰＶＣ／ＰＰＣ不相容，但它们不相容的程度受分子量、共混比例及共混方法等因素的影响，并根据玻璃化转变温度计算出溶液２共混试样ＰＰＣ富相中ＰＶＣ的质量百分含量。用ＤＭＡ说明了ＮＢＲ／ＰＰＣ对ＰＶＣ／ＰＰＣ共混体系具有良好的增容作用，共混体系中ＰＰＣ的用量对共混体系相容性有一定程度的影响，加入适量的ＰＰＣ可提高共混试样     

HPB－b－PMMA增容PVC／PE共混物球晶和结晶行为研究

以小角激光散射（ＳＡＬＳ）和广角Ｘ光衍射（ＷＡＸＤ）技术，测定了氢化聚丁二烯－聚甲基丙烯酸甲基嵌段共聚物（ＨＰＢ－ｂ－ＰＭＭＡ）增容的聚氯乙烯（ＰＶＣ）和聚乙烯（ＰＥ）共混物的球晶形态和结晶度。从该共混物中ＰＥ的结晶状况得出，增容剂ＨＰＢ－ｂ－ＰＭＭＡｄ在降低ＰＥ结晶能力、增加ＰＥ／ＰＶＣ界面粘合并形成ＰＶＣ和ＰＥ相间的部分相容性有着重要的作用。     

新型渗透汽化透水膜的研制（II）：膜的结构和性能

确定聚合物共混的相容性最常用的方法是通过测定共混物的玻璃化转变温度（Ｔｇ），本文利用ＤＳＣ－７（Ｅｐｓｏｎ）测定了不同共混比的ＰＶＡ，ＣＳ共混物的玻璃化转变温度，结果表明ＰＶＡ，ＣＳ之间有良好的相容性。本文利用扫描电子显微镜（ＳＥＭ），红外光谱（ＩＲ）和Ｘ－射线衍射（ＸＲＤ）等现代分析仪器，对研制的多元酸交联的ＰＶＡ－ＣＳ／ＰＳＦ膜结构进行了观察测试，探讨了膜结构与性之间的关系。     

聚醚型多嵌段聚氨酯与氯化聚氯乙烯共混物的相容性研究

用ＤＳＣ及ＦＴＩＲ方法研究了聚四亚甲基醚型多嵌段聚氨酯（ＳＰＵ）与氯化聚氯乙烯（ＣＰＶＣ）共混物的相容性。结果表明,共混物具有两个分立的Ｔｇ,属不相容体系。ＦＴＩＲ结果表明随共混物中ＣＰＶＣ含量的增加,其ＳＰＵ组分的氢键键合的Ｃ＝Ｏ、Ｎ－Ｈ吸收峰所占的分数明显减少,ＣＰＶＣ与ＳＰＵ分子间存在较强的相互作用。多嵌段聚氨酯硬段含量的增加,加强了ＳＰＵ分子间的相互作用,同时也减小了共混物两组分的相容性。     

PVA—CS共混体系相容性的研究

利用ＤＳＣ等方法，研究了ＰＶＡ－ＣＳ二元共混体系的相容性。结果表明，ＰＶＡ与ＣＳ之间存在一定的相互作用为部分相容体系，以Ｆｌｏｒｙ－Ｈｕｇｇｉｎｓ的高分子溶液理论为基础，通过Ｗｏｏｄ或Ｆｏｘ方程，计算出不同共混出ＰＶＡ－ＣＳ共混体系两相中二组分的表面质量分率，进而计算出体系的聚合物－聚合物Ｆｌｏｙ－Ｈｕｇｇｉｎｓ相互作用参数，ｘ１２或ｇ１２，对ＰＶＡ－ＣＳ共混体系的相容性进行了验证。     

FPE／CPE／PVC体系的界面粘结力、形态结构与性能的关系

用ＦＴ－ＩＲ光谱证实发了ＰＶＣ与ＦＥ-g-DBM(下称ＦＰＥ,用固相接枝法自制的固接枝物）之间存在着氢键和偶极－偶极的作用,其中以氢键作用为主。测定了ＰＶＣ／ＣＰＥ／ＰＥ和ＰＶＣ／ＣＰＥ／ＦＰＥ合金的力学性能,用ＤＳＣ、相衬显微镜及ＳＥＭ表征了这两个体系的形态结构、研究了共混物中界面粘结力与与形态结构、合金性能的相互关系。     

Influence of P3HT concentration on morphological, optical and electrical properties of P3HT/PS and P3HT/PMMA binary blends

Poly(3-hexylthiophene) (P3HT) has interesting optoelectronic properties and a wide variety of applications such as solar cells and O-FET devices. It is a soluble conductive polymer but their mechanical properties are poor and its conductivity is unstable in environmental condition. With the finality of overcome these disadvantages, P3HT binary blends with two insulating polymers, polystyrene (PS) and polymethylmetacrilate (PMMA), have been synthesized by direct oxidation of 3-hexylthiophene with FeCl₃ as oxidant inside the insulator polymers. Molecular weight and polydispersity of P3HT polymer were measured by size exclusion chromatography and the degree of regioregularity by ¹H RMN. P3HT/PS and P3HT/PMMA thin films were prepared by spin-coating technique from toluene solution at different P3HT concentrations. The doped films were obtained by immersion during 30 s in a 0.3 M ferric chloride (FeCl₃) solution in nitromethane. A classical percolation phenomenon was observed in the electrical properties of the binary blends, it was smaller than 4 wt.% of P3HT in the blend. Atomic force microscopy and confocal microscopy showed a phase-separated morphology. Variation in the surface morphology of the blends was observed, which was a function of the polymer concentration and the type of insulator polymer used in the blends. The insulator polymer was segregated on the surface of the films and showed pit and island-like topography. The pit and island size changed as a function of the polymer concentration. Optical absorption properties as a function of the P3HT concentration in the undoped and doped state were analyzed. In doped state, the bipolaron bands in the PS/P3HT and PMMA/P3HT blends were observed from a P3HT concentration of 1 wt.% and 3 wt.%, respectively. Finally, the polymers were analyzed by thermogravimetric analysis and infrared spectroscopy.     

New aspects of the microstructure of glassy PET/PEN blends as revealed by microhardness

The microhardness of films of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalene-2,6-dicarboxylate) (PEN) blends prepared by co-precipitation from solution followed by melt-pressing and quenching was determined. The miscibility, transesterification and crystallization properties of these blended films were reported previously [1]. The PET/PEN compositions chosen were 10/90, 30/70, 44/56, 60/40, 70/30 and 90/10. The microhardness of films was notably affected by the composition. It is shown that the deviation of microhardness from the additivity law of the single components depends on the time for which the blend was melt-pressed before quenching in ice water. The results are discussed in light of changes occurring from the initial two-phase structure of the single components through the one-phase structure up to the PET-co-PEN obtained by transesterification of the two components. This revised version was published online in November 2006 with corrections to the Cover Date.     

Nanoalloys based on clays: intercalated semicrystalline blends of syndiotactic polystyrene with poly(2,6-dimethyl-p-phenylene oxide)

Nanoalloys of syndiotactic polystyrene with poly(2,6-dimethyl-p-phenylene oxide) clay were prepared by a solution intercalation technique using 1,1,2,2-tetrachloroethane. A mixed intercalated/exfoliated morphology in the nanoalloys containing organo-clays is evinced by transmission electron microscopy. Thermal stability is found to improve with 5% by weight of organo-clays, but a reverse trend is observed by increasing the concentration of clay. The influence of montmorillonite clays in isothermal melt-crystallization behavior of blends was thoroughly investigated by using differential scanning calorimetry and wide-angle X-ray diffraction. A considerable change in polymorphic behavior of syndiotactic polystyrene is observed by the incorporation of different clays into the blends, and the temperature window of isothermal crystallization for the formation of a-crystals of syndiotactic polystyrene is found to broaden in the presence of organo-clays. In contrast, the pristine clay is found to induce only the beta-crystal of syndiotactic polystyrene at all the crystallization temperatures studied in this work. The amorphous component poly(2,6-dimethyl-p-phenylene oxide) affects the crystallinity of syndiotactic polystyrene adversely and favors the beta-form of syndiotactic polystyrene in blends; a-crystals are observed in the nano-alloys containing 20 wt% of poly(2,6-dimethyl-p-phenylene oxide). The crystalline morphology, as characterized by polarized optical microscopy, clearly indicates rapid formation of the alpha-form induced by the nanoscale dispersion of organo-clays in spherulites of smaller dimension.     

Morphological, crystallization and plasticization studies on isomorphic blends of poly (vinyl fluoride) (PVF) and poly (vinylidene difluoride) (PVDF): using microhardness, XRD and SEM techniques

Property modification by blending of polymers has been the area of immense interest. In this paper, the isomorphic blends of two polymers poly (vinyl fluoride) (PVF) and poly (vinylidene difluoride) (PVDF) with different ratios were prepared using solution cast technique. The microhardness studies have been carried out on pure and polyblend specimens at various loads to test the plasticization and hardening effects using Vickers microhardness testing. The X-ray diffraction (XRD) study has been utilized to detect the crystalline and amorphous characteristics of specimens. Thus PVDF acts as plasticizer in the polyblend when the content of PVDF is relatively high as compare to PVF. When the PVF is major component in the polyblend, the microhardness of the blend specimen increases and the isomorphic blend specimens with 50:50 proportion of two polymers exhibit the maximum value of microhardness. Scanning electron microscopy (SEM) micrographs indicate complete chain formation with uniform texture, when the two polymers are blended in equal proportions. The findings of XRD and SEM have been correlated with the microhardness values.     

Phase separation in blends of oligo (caprolactone glycol)-based polyurethane with poly(vinyl chloride)

The structure of o!igo (caprolactone glycol)-based polyurethane-poly(vinyl chloride) (PVC) blends obtained from tetrahydrofuran solution was studied by X-ray diffraction and electron microscopy. The system is characterized by a oornp!ex phase diagram with two types of equilibria: (1) crystal-liquid equilibrium in the region of blend compositions up to 40 wt% PVC; (2) liquid-liquid equilibrium in the region of man compositions. The crystallization kinetics of oligo(caprolactone) polyurethane blocks from an initially compatible amorphous blend was investigated. Small-angle X-ray cattering (SAXS) studies provide evidence that the amorphous component (PVC) is incorporated in the interlamellar crystalline regions of the compositions. The amorphous blends are characterized by the presence of modulated structures at two scale levels, this being explained as e result of the process in which the bulk samples were obtained from a three-component polymer-polymer-solvent system.     

溶液浓度和非溶剂比例对PVC膜形貌和疏水性能的影响

目的 研究溶液质量分数和非溶剂体积分数对PVC薄膜表面形貌和疏水性能的影响,以获得具有超疏水表面的PVC薄膜。方法 以四氢呋喃为良溶剂、乙醇为非溶剂,利用非溶剂诱导相分离的原理,采用旋涂法在玻璃基底上制备超疏水的聚氯乙烯（PVC）涂膜;通过对PVC样品的疏水性、表面形貌、结晶性能和热性能进行分析,探究溶液质量分数以及非溶剂的体积分数对PVC样品性能的影响。结果扫描电镜和接触角测试表明,添加一定体积分数的乙醇使得所制备的PVC样品形成了多孔膜层以及纳米级聚合物球粒,从而提高了PVC样品的疏水性。XRD测试结果表明,添加乙醇并不会改变PVC样品的无定形结构。结论 PVC溶液质量分数对所制备PVC样品的疏水性能和表面结构没有明显影响,乙醇体积分数为30%～40%时,可形成表面水接触角大于150°的超疏水表面。     

Consistent analysis of cloud points and spinodal – compatibility of P (αMS-CO-AN) and P (MA-CO-MMA)

The two copolymers poly(α-methylstyrene-co-acrylonitrile) (P(αMS-co-AN)) and poly(methyl acrylate-co-methyl methacrylate) (P(MA-co-MMA)) are traded by the BASF AG, Ludwigshafen, under the names Luran and Lucryl, respectively. We have studied Luran KR2556 with the molar mass of M_w = 92 kg/mole (M_w/M_n = 2.5), which has the copolymer composition of 50% αMS and AN, respectively. Lucryl has a similar molar mass of M_w = 88 kg/mole (M_w/M_n = 2.5) and is available with various MA fractions between 1 and 14%. Luran + Lucryl blends prepared by solution casting from acetone are miscible at temperatures below 130 °C. At higher temperatures they show a lower critical solution temperature (LCST) behavior. Temperatures of demixing depend strongly on the MA fraction. The minima of the cloud point curves are found for Luran concentrations between 20 and 35%. We have used results from transmission electron microscopy (TEM) [1, 2] to reveal the morphologies of demixed Luran + Lucryl blends for different compositions and temperatures. This enables us to distinguish between demixing by nucleation and growth in the meta-stable region of the blend system and the spinodal decomposition. The results from cloud point and TEM measurements yield constraints for the spinodal curve. The spinodal is calculated consistantly utilizing a temperature and concentration dependent interaction parameter defined by Staverman [3]. We also estimate the interaction parameter for blends of Luran with pure PMMA and PMA. Electronic Publication     

Cold crystallization studies on PET/PEN blends as revealed by microhardness

The cold crystallization of amorphous films of poly(ethylene terephthalate) (PET) and poly(ethylene naphthalene-2,6-dicarboxylate) (PEN) blends, with different composition, prepared by co-precipitation from solution followed by melt-pressing for 2 min at 280°C and quenching in ice-water, was followed by measuring the microhardness, H, in real time as a function of crystallization temperature and time. An analytical model was derived, relating properties of the individual components to the blend microhardness based on an Avrami-type equation to account for the crystallization of the components upon heating. Fitting of the model to the experimental results revealed a two-step hardening process of the blends. The degree of transesterification of the blends, can be estimated with this model. Finally, a removal of the physical ageing, inducing a decrease in H of PET in the blend, was observed upon heating above its glass transition temperature. This revised version was published online in November 2006 with corrections to the Cover Date.     

Crystallization kinetics of SbxSe100−x thin films

The crystallization kinetics in Sb_xSe_100−x films with 39≤x≤58is studied by monitoring the optical transmission of the films during both isothermal and constant rate heatings. The structure of the films upon crystallization and at certain intermediate stages is studied by electron microscopy techniques. The results are analyzed in the frame of the Johnson-Mehl-Avrami theory in order to determine the kinetic parameters (Avrami exponent, activation energy and frequency factor) in addition to the crystallization temperature. The results show that film crystallization is always preceeded by a relaxation process which modifies substantially the optical properties of the amorphous material. Amorphous films with compositions close to the stoichiometric compound (Sb₂Se₃) are found to show the highest activation energy for crystallization.     

Preparation and characterization of nanostructured copper bismuth diselenide thin films from a chemical route

Thin films of copper bismuth diselenide were prepared by chemical bath deposition technique ontoglass substrate below 60°C. The deposition parameters such as time, temperature of deposition and pH of the solution, were optimized. The set of films having different elemental compositions was prepared by varying Cu/Bi ratio from 0·13–1·74. Studies on structure, composition, morphology, optical absorption and electrical conductivity of the films were carried out and discussed. Characterization includes X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive X-ray analysis (EDAX), absorption spectroscopy, and electrical conductivity. The results are discussed and interpreted.