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The processes of the preparation of highly conductive polymer composites of poly(methyl methacrylate) and polypyrrole (PMMA/PPy) have been studied. The composites were prepared by a chemical modification method resulting in a network-like structure of polypyrrole embedded in the insulating polymer matrix. Water was used as a solvent. The content of polypyrrole was determined by elemental analysis...
In order to study the tacticity effect of the backbone on the thermotropic properties of side-chain liquid crystalline (SCLC) polymers, the synthesis of four polymethacrylates with different tacticities and bearing methoxy biphenyl mesogenic groups was carried out. Homopolymers were obtained upon photopolymerisation at low temperature of two mesogenic methoxy biphenyl monomers, with and without ethylene...
The use of reactive solvents provides a unique opportunity to extend the processing characteristics of both intractable and standard (tractable) polymers beyond existing limits. The polymer to be processed is dissolved in the reactive solvent (monomer) and the solution is transferred into a mould. Upon polymerisation, phase separation and phase inversion occur and the originally dissolved polymer...
Most aromatic poly(amic acid)s, which are precursor polymers of polyimides, are thermally converted to the corresponding polyimides via imide-ring closure formation over their glass transition temperature (T g ) ranges or below. In addition, it is very difficult to remove completely solvents used in the synthesis from their cast samples, due to the formation of complexes between the solvent...
Studies were undertaken to gain mechanistic information on lactone ring-opening polymerisation reactions using Candida antarctica lipase B (Novozym 435) as the catalyst and ε-caprolactone as the monomer. Polymerisations were performed in organic solvents as well as without solvent at 60 o C. Candida antarctica lipase B catalysed concurrently with the intermolecular ring-opening polymerisation,...
Property modification of an inorganic surface can be readily achieved through the use of macromolecules chemically grafted to the surface at specific functional sites along the chain. While numerous efforts have addressed the properties of linear chains grafted at one end (tails), relatively few have extended such studies to include double-tethered chains (loops). In this work, we consider loop/tail...
Attempts to produce detectable levels of ions from oligomers of linear polysulfides (LPs) H(SC 2 H 4 OCH 2 OC 2 H 4 S) n H (n up to 24) by matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) mass spectrometry failed with all common matrix/cation combinations except 9-nitroanthracene containing silver trifluoracetate. The latter matrix...
The three-dimensional crystal structure of isotactic polypropylene in its β-polymorphic form has been refined against electron diffraction intensity data. Microtwinning by merohedry, probably in two antichiral domains in space groups P3 1 and P3 2 , was identified by sharp continuous diffraction in h0l patterns from epitaxially crystallized samples. Nevertheless, a rather simple...
First lactamimide monomers were synthesised by the bisimide-lactam ring contraction and polymerised by the high-temperature transesterification in the melt to give lactamimide-containing polymers. The polymers were amorphous with good film-forming properties, soluble in common organic solvents, and showed from low to medium molecular weight. Lactamimide-containing polymers bearing aliphatic spacers...
A model based on the concept of fractional calculus is proposed to predict the viscoelastic behaviour of amorphous polymers in the temperature range from T g - 190 o C to T g + 25 o C. Poly methyl methacrylate (PMMA) has been chosen as a model amorphous polymer. PMMA has been studied by dynamic mechanical spectrometry and the experimental data have been compared with...
Poly(vinylidene fluoride) (PVF 2 ) gels in glyceryl tributyrate (GTB) with fibrillar morphology in the dried state. The gels are transparent and WAXS results indicate the presence of α-phase PVF 2 crystals in the gels. The gelation rate (t -1gel ) has been measured by the test tube tilting method and has been analysed with the equation t -1 ...
Baked starch foams were characterized by several physical methods in order to better understand the relationship between process parameters and starch foam structure. In this process, a thin-walled object such as a plate is formed by heating a starch batter inside a closed mould. Normal corn and potato starches are gelatinized by this treatment but some swollen granules remain. The foams have a...
Very low molecular weight oligomers were prepared and evaluated as non-volatile reaction media. This paper reports the results of a preliminary feasibility study on the potential for oligomers to function as environmentally benign and cost-effective replacements for liquid solvents. The preparation and solvent efficacy are reported on two series of low molecular weight vinylpyrrolidone (VP) rich...
The gelation of a polyvinylalcohol-glutaraldehyde-water solution confined in a Bentheimer sandstone was characterized by carrying out 1 H-n.m.r. spin-lattice relaxation rate measurement (1/T 1 ) and pulse field gradient diffusion (D) measurements at 67 o C. At any time during the gel-reaction neither the longitudinal magnetization versus storage time nor the echo-amplitude...
This work reports the synthesis of new diamantane-based polyimides by the reaction of 4,9-diaminodiamantane (I) with various aromatic tetracarboxylic dianhydrides. The polyimide film IV a has a low dielectric constant of 2.7 and a low moisture absorption of 0.205%. The number-average molecular weight (M n ) of polyimide IV a is 37 kg/mol. Dynamic mechanical analysis (DMA)...
The separation of blends of polymethacrylates was accomplished by liquid chromatography at the critical point of adsorption. Using a non-polar stationary phase and tetrahydrofuran-acetonitrile as the eluent, separations were conducted under chromatographic conditions, corresponding to the critical point of adsorption of the least polar component of the blend. After the separation step the blend...
The synthesis of a series of N-(hydroxyphenyl) succinimides is described along with their reaction with HMTA. The succinimides serve as a model for the more complicated polyimide/HMTA systems. Both benzoxazine and benzylamine type intermediates have been identified as the initial major intermediates formed depending on the substitution pattern of the phenolic ring. The rate of reaction of HMTA...
In this second part, we examined two possibilities for the synthesis of new acrylic organotitanium polymers that could be of great interest in the field of self-polishing antifouling coatings: copolymerization of acrylic organotitanium monomers with methyl methacrylate via free-radical initiation in organic solvents, or esterification of the acid functions of an available acrylic polymer with titanium...
A novel optically active monomer containing a photochromic chromophore, such as trans-(S)-4-(2-methacryloyloxypropanoyloxy)azobenzene and its low molecular weight model compound trans-(S)-4-(2-pivaloyloxypropanolyloxy)azobenzene were prepared. Free radically initiated homopolymerization of the methacrylic monomer afforded in fairly high yield a rather high molecular weight polymer which was molecularly...
Solid-state properties of undoped gels of poly(3-n-octylthiophene) (POT) are investigated by N 2 BET surface measurements, X-ray diffraction and small-angle X-ray scattering (SAXS) experiments. The observed variations in compacity, crystalline domain sizes and typical sizes of large-scale heterogeneities versus the crosslink ratio, R i , all exhibit an extremum for the gel R i...
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