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Hexamethylenediammonium adipate (PA 6,6 salt) was solid state polymerized in the temperature range of 158–190°C, in a thermogravimetric analysis (TGA) chamber, which simulates a polyamidation reactor. A mechanism based on the role of the volatile component of the salt (i.e. hexamethylenediamine) is found to predominate: the diamine escapes along with polycondensation water, meanwhile this volatilization...
The effects of methacrylic acid (MAA) on the physical properties of polymer made by emulsion copolymerization of butyl acrylate (BA) and MAA were examined. Emulsion polymerizations were performed with and without MAA and at temperatures of 0.1 and 50°C, using redox initiation so that the radical flux was essentially independent of temperature. The presence of methacrylic acid had only a small effect...
The quantitative investigation of the radical scavenging properties of polyaniline (PANI) upon reaction with excess of the stable DPPH radical (a 4:1 ratio of DPPH to aniline units in the polymer) was carried out using 15 N and 13 C solid state NMR spectroscopy. During the process the polyaniline was oxidised so that the imine content increased from 45 to 65%. The extent of oxidation...
Toluene diisocyanate based polyurethanes with amide extenders were synthesized poly(propylene oxide) with a number average molecular weight of 2000 and endcapped with toluene diisocyanate was used as the polyether segment. The chain extenders were based on poly(hexamethylene terephthalamide): hexamethylene diamine, bisamine-diamide and bisamine-tetra-amide. The linear poly(ether bisurethane-bisurea-amide)s...
This study concerns understanding of the underlying mechanistic pathways in high temperature solution polymerization of n-butyl acrylate (nBA) in the absence of added thermal initiators. The particular system of interest is the batch polymerization of nBA in xylene at temperatures between 140 and 180°C with initial monomer content between 20 and 40wt%. A mechanistic process model is developed to capture...
Radially aligned polyaniline dendrites with nanotube junctions have been synthesized using tartaric acid as the dopant without the aid of any surfactants. These dendritic nanotubes with 80–400nm in outer diameter, 30–50nm in wall thickness, and several micrometers in length can self assemble into urchin-like nanostructures. The geometrical shape of the individual branch is a cone. The nanotube junctions...
The in situ rheological behavior across the gelation threshold has been investigated for an affine network of a completely charged cationic monomer (3-acrylamidopropyl)-trimethylammonium chloride (APTMAC1) when it is crosslinked with a neutral crosslinker (N,N′-methylenebisacrylamide) to form a fully charged novel cationic hydrogel. The elastic moduli (G′) near the gel point (during the crosslinking...
The kinetics of thermally initiated cationic epoxy polymerization and free radical acrylate photopolymerization were studied using photo-differential scanning calorimetry. The reactions of the neat monomers and diluted monomers as well as interpenetrating polymer networks (IPNs) were studied as a function of dilution by the other monomer and temperature. The reaction sequence was also varied to study...
The branched copolymers prepared from ethylene and α-olefins using rac-Et(Ind) 2 ZrCl 2 /MMAO catalyst system were studied. Both the absolute molecular weight (M¯w) and the molecular size (radius of gyration, R g ) of the polymers eluting from gel permeation chromatography (GPC) columns were obtained simultaneously via a high temperature GPC coupled with a two-angle laser light...
Recent studies have shown that cobalt catalysts, used for curing of alkyd coatings, are potentially carcinogenic, and hence replacement by new environmental friendly catalysts is needed. The influence of different metal based catalysts on the oxidation process has been studied extensively in model systems, consisting of unsaturated oils. However, these results may not be representative for real coatings,...
The physical properties of n-alkyl acrylate copolymers containing one crystallizeable monomer and one non-crystallizeable or slightly crystallizeable monomer, including thermal characteristics, structure as determined by small angle X-ray scattering, and gas permeability as a function of temperature, were examined in detail and compared to the corresponding homopolymers and copolymer systems containing...
The effects of an anionic surfactant, sodium dodecyl sulphate (SDS), on the optical transmittance, thermal, and rheological properties of methylcellulose (MC) aqueous solutions have been studied. The particular interest of this work was focused on the effects of SDS on the sol–gel transition of MC. Basically, two effects of SDS have been identified, which are the salt-out and salt-in effects at low...
The method of formation of well-defined polymer brushes based on the nitroxide mediated polymerization (NMP) of n-butyl acrylate (BA) initiated from a self-assembled mono-layers (SAMs) of an azoic initiator in the presence of a stable nitroxide radical is described. After preliminary qualitative characterization by X-ray photoelectron spectroscopy, the samples were studied by ellipsometry in order...
As the applications for polymeric membranes expand, new challenges arise. One of the largest of these challenges is the plasticization caused by strongly swelling penetrants such as carbon dioxide at elevated pressures. A considerable amount of material research has investigated crosslinking of dense film membranes to increase plasticization resistance. This paper extends such materials research to...
Time- and temperature-dependent SAXS and WAXS experiments on poly(l-lactide) were used (i) to establish the relationships between the crystallization temperature, the crystal thickness and the melting point, (ii) to follow recrystallization processes during heating, and (iii) to detect perturbations of the crystalline order. The studies showed several peculiarities: (i) although no solid state thickening...
Direct covalent attachment of amorphous and semicrystalline polyetherketones onto the surface of either an as-received multi-walled carbon nanotube (MWNT) or a vapor-grown carbon nanofiber (VGCNF) in polyphosphoric acid (PPA) with optimized P 2 O 5 content resulted in uniform grafting of polyetherketones to these carbon nanoscale materials. Soxhlet extraction experiment, the spectra...
The phase diagrams of nanoparticles based on self-assembled amphiphilic poly(1,2-butadiene)-b-poly(ethylene oxide) diblock copolymers (PB-b-PEO) and subsequent intra-micellar cross-linking in methanol and water show that the obtained morphology of the nanoparticles depends on: (i) the block ratio; (ii) the block length; (iii) the solvent; and (iv) the PEO-sided end group. Depending on these parameters,...
In this paper, we have investigated the electrochemical behavior of a soluble copolymer of poly(aniline) (PANI) and poly(phenylene sulfide) in organic media. By using ‘in situ’ UV–vis and Raman spectroscopies, it was proved that during the oxidation of the first cycle, polarons and bipolarons are formed consecutively, due to the loss of electrons from the nitrogen and sulfur, respectively. In addition,...
Perfluoropolyether-based organic–inorganic hybrids were prepared by sol–gel process and applied as functional coatings onto glass substrates. Contact angle analysis and X-ray photoemission spectroscopy were carried out in order to characterize the surface of the prepared coatings. A strong hydrophobic and lipophobic character was observed for all tested compositions. The wettability behaviour was...
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