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The staining of poly(ethylene terephthalate) (PET) by ruthenium tetroxide (RuO 4 ) is used to obtain a contrast at the crystalline lamellar scale in transmission electron microscopy. This paper demonstrates the efficiency of this technique conducted in vapor phase on ultracut bulk samples. Advantages of this method against other contrast enhancing techniques and the parameters of staining...
A novel thermal model is developed for surface depth profiling of heterogeneous polymeric surfaces using step-scan photoacoustic Fourier transform (SS PA FT-IR) spectroscopy. This approach is based on the propagation of thermal waves generated during the photoacoustic effect which travel to the film–air (F–A) interface, thus generating acoustic signals above the surface, which upon Fourier transform,...
Decreasing carboxyl retention in deposits from the glow region of an acrylic acid plasma was measured by X-ray photoelectron spectroscopy and chemical derivatisation as the collection distance from the monomer vapour inlet was increased. Volatilisation of plasma polymerised acrylic acid was detected after trifluoroethanol derivatisation; this is correlated with evaporation of low molecular weight...
The melting and crystallization behavior of poly(trimethylene 2,6-naphthalate) (PTN) are investigated by using the conventional DSC, the temperature-modulated DSC (TMDSC), wide angle X-ray diffraction (WAXD) and polarized light microscopy. It is observed that PTN has two polymorphs (α- and β-form) depending upon the crystallization temperature. The α-form crystals develop at the crystallization temperature...
The effect of thermal history on the orientation and relaxation behavior of blends of polystyrene with poly(vinyl methyl ether) (PS/PVME) has been studied using polarization modulation infrared linear dichroism (PM-IRLD) and differential scanning calorimetry (DSC). DSC shows that miscible PS/PVME blends containing 70% of PS can be physically aged at temperatures above their mean glass transition temperature...
The rheological properties of a thermoplastic polyurethane (TPU) were studied at small and large deformation via three different types of rheometry: dynamic shear, capillary, and torque (an instrumented batch mixer). The effect of degradation during TPU processing on the melt viscosity was investigated and several factors, such as temperature, time, shear stress, and flow type that may affect the...
Alkoxy-substituted organopolysilane homopolymer (poly[SiMe(OR)] n ) and random copolymers (poly[SiMe(OR)] m [SiMeR′] n were synthesized and the solvatochromism and thermochromism for their absorption and fluorescence spectra were examined. The band maxima shifted to longer wavelengths with an increase in the ratio of the alkoxy side chains; however, the influence of the solvent...
To modify the surface of vapor grown carbon fiber (VGCF), poly(ethylene-block-ethylene oxide) (PE-b-PEO, M n =1400, PEO content=50wt%) was successfully grafted onto the surface by using γ-ray irradiation of the PE-b-PEO-adsorbed VGCF in solvent-free system. It is found that the percentage of polymer grafting reached 15.0% when the PE-b-PEO-adsorbed VGCF was irradiated by γ-ray over 40kGy dose...
Solvent-free, photoreactive particles of 2,5-distyrylpyrazine (DSP) monomer were developed by rapid precipitation from an expanding supercritical chlorodifluoromethane solution. DSP polymer particles were produced by solid-state photopolymerization. DSP particles below a critical diameter of about 0.5 μm were found to be mechanically stable and did not fragment upon photopolymerization. The rate of...
The size, shape, and connectivity of cavities in the crystals of syndiotactic polystyrene were investigated by molecular dynamics simulation. Cluster analysis of the free volume in the crystals clearly reveals the cavity structures: large individual holes are in an orderly manner connected by narrow channels. We call such a cavity structure a ‘molecular cavity’. The diffusion behavior and solubility...
The inversion-recovery cross-polarization (IRCP) sequence used for measuring cross-relaxation time (T CH ) is modified to obtain signals that show exponential or spin-lock (SL) decay to zero. The new sequence may, therefore, be analogously abbreviated as SLCP. Poly(R)-(3-hydroxybutyrate-co-3-hydroxyhexanoate) {P(HB-HHx) (85:15)} is found to be more mobile than poly(R)-(3-hydroxybutyrate) {PHB}...
A novel ether connected epoxy star like polymer was synthesized by selective reaction of water soluble polyhydroxy fullerene (fullerenol) with a commercial grade cycloaliphatic epoxy resin (CY-230, Ciba Geigy) in heterogeneous medium at ambient alkaline condition using tetrabutylammonium hydroxide as phase transfer catalyst. The reaction went well in such conditions and the hydroxy groups of fullerenol...
Porcine pancreas lipase (PPL) immobilized on silica particles with different size were prepared and employed successfully for ring-opening co-polymerization of 5-benzyloxy-trimethylene carbonate (BTMC) with 5,5-dimethyl-trimethylene carbonate (DTC) for the first time. Three kinds of silica particles with different sizes (150–250, 75–150 and 1 μm) were selected as carriers for enzyme immobilization...
Various substrates such as glass slides and silicon wafers were modified by styrylethyltrimethoxysilane to attach double bonds to those surfaces. The double bond layer was initiated and capped by benzoyl peroxide (BPO) and 2,2,6,6-tetramethylpiperidirooxy (TEMPO), respectively, to form ‘living’ free radical layer from which polystyrene brushes were grown. The density of double bonds on the surface...
In situ composite films were prepared by a two-step method. First, polypropylene and thermotropic liquid crystalline polymer (TLCP), Rodrun LC5000 (80mol% p-hydroxy benzoic acid (HBA)/20mol% polyethylene terephthalate (PET)), were melt blended in a twin-screw extruder and then fabricated by extrusion through a mini-extruder as cast film. Rheological behavior of the blends, morphology of the extruded...
The present study compared the crosslinking performance of single site linear low density polyethylenes (LLDPE) with high pressure, free radical polymerised, low density polyethylenes (LDPE). The difference in crosslinking performance is not fully explained by different structural parameters such as molar mass distribution (MMD), M n , MFR 2 value and vinyl groups but is related more...
In this paper, the influence of processing conditions on the spatial distribution of the molecular orientation was determined within the depth of the thickness of injection molded isotactic polypropylene (iPP) plates. Small 35μm-thick slices were microtomed from the surface to the core of 1 and 3mm-thick plates. The orientation functions along the three crystallographic axes were determined on the...
The effects of rubber type and particle size on the mechanical properties of glass fiber reinforced blends of nylon 6 and EPR/EPR-gMA or SEBS/SEBS-g-MA were investigated; rubber particle size in the two systems could be controlled by varying the ratio of EPR to EPR-g-MA or SEBS to SEBS-g-MA. Unreinforced materials with the highest levels of toughness did not necessarily lead to the highest fracture...
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