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The main difficulties in wood and pulp analyses arise principally from their numerous components with different chemical structures. Therefore, the basic problem in a specific analytical procedure may be the selective separation of the main carbohydrate-derived components from lignin due to their chemical association and structural coexistence. The processing of the wood determines some structural modification in its components depending on the type
Read moreLignin’ characterisation is a very difficult task, if considering its diversity with respect to both origin and method of separation. The heterogeneity of lignin is caused by variations in polymer’s composition, size, crosslinking, functional groups, and linkage type between the phenyl propane monomers (p – hydroxyl phenyl, guaiacyl and syringyl units). The elaboration of well-defined analytical methods for lignin characterization is very important
Read moreWood deterioration, an essential environmental process through which complex organic matter is recycled, destroys valuable historical and cultural objects made of wood, which causes serious losses in the cultural heritage. Information on some specific features, associated with different types of degradation of lime wood is important in planning appropriate conservation and specific consolidation procedures or other treatments. A description of the
Read moreThe paper presents the preparation of poly(aspartic acid) (PAAs) from maleic anhydride and ammonia through a two steps reaction: first the polysuccinimide (PSI) obtainment followed by the hydrolysis reaction of PSI in order to open the imide group and to prepare the polyaspartate. Poly(aspartic acid) as friendly environmental and biodegradable product can be used in pharmacy, cosmetics, agriculture, etc.
Read moreThe compatibility of the hydroxypropyl cellulose (HPC) with maleic acid–vinyl acetate copolymer in the solid state was studied by thermogravimetry, thermooptical analysis, differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), and optical microscopy. It was established that physical interactions are prevalent in blends with a high content of HPC, whereas chemical interactions predominate in blends with a medium
Read moreThe natural polymer/synthetic polymer combination offers an attractive solution to create environmentally friendly degradable materials, which should not have negative effects on the environment. A modern solution to create such of materials consists in using natural fibres as reinforcement agent in composites applicable in various fields as automotive industry, building, etc. Their performance strongly depends on solid reinforcement-polymer matrix
Read morePolyaniline/maleic acid copolymers composites were synthesized by chemical in situ polymerization of aniline using ammonium peroxidisulfate as oxidant, in the presence of water soluble copolymers containing carboxylic groups. Fine dispersions of composite materials, soluble in N,N dimethylformamide or dimethyl sulfoxide were obtained which can be processed as thin films and membranes for application as proton-conductive materials for electrolyte
Read moreComposites of PANi and TiO2 nanoparticles were investigated for applications in direct methanol fuel cell and alcohol sensors. Anilinium sulfate and TiO2 with nanometric size were electropolymerized in 0.5M H2SO4 solution on carbon paper. Oxidation and response to methanol was measured by chrono amperometry and elctrochemical impedance spectroscopy.
Read moreMicrocellular carbon (CMC) is a distinct material obtained by the polymer matrix pyrolysis containing hard fusible and inert micronized materials by comparison with carbon foam where usual the pyrolized polymers are foamed with different agents. The microcellular carbon is an advanced material due to its properties related to inertness and thermal conductivity where high rate of heat exchange is required and its application to gas separation due
Read moreThe objective of our investigations was to establish the electrical behavior of composites when structural changes are induced by different types of additives. The composites based on conductive matrix are obtained by additivation of a fractionated coal tar pitch with nanocarbon. The aditivated fractionated coal tar pitch was heat treated at mesophase condensation (440°C) and coke transition (900°C) temperatures. These structural changes have been
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