Thermal analysis of interpenetrating polymer networks through molecular dynamics simulations: a comparison with experiments

International audienceIn this work, we verified the synthesis of a novel sequential interpenetrating polymer network, composed of poly(2-hexyl-ethylacrylate) and poly(n-butyl acrylate) named PHEA and PBuA, respectively, and we studied the physical properties by means of thermogravimetric analysis and differential scanning calorimetry techniques. An increase in the thermal stability is found with the increase in the density of the polymer network, and the amount of the absorbed monomer by the network has a great influence on its behavior and glass transition temperature. We supplement this job by applying molecular dynamics simulation methods (free volume, radial distribution function) to investigate the properties of these polymer networks and effects of composition ratios and temperature by introducing a new comprehensive and reproducible atomistic model for the generation and property evaluation of interpenetrating polymer networks. The simulation presented from the discontinuity in the different plots versus temperature of the specific volume or radial distribution function, demonstrates that the glass transition temperature (Tg) values were in good agreement with experimental values

Chemical and thermal characteristics of soluble polysaccharides from fruit pericarps of the Algerian Argania spinosa

Soluble polysaccharides were isolated from fruit pericarps of the Algerian Argania spinosa. The cell wall fraction was subjected to sequential extractions with H2O (2 × 2 h at 100oC), EDTA (1%, 6 h at 80oC) and KOH(1 and 4 M, 14 h at 25oC) . The structures of the obtained polysaccharide fractions were characterized using gas chromatography (GC), infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The presence of arabinose, galactose and rhamnose in the pectin fractions suggests the presence of rhamnogalacturonan, while the abundance of xylose in the hemicellulosic fractions indicates the presence of xylan. The DSC data revealed the endothermal behavior of all the soluble polysaccharides and only two thermal transitions, the glass transition (Tg) and the fusion transition (Tf) have been recorded

Novel interpenetrating polymer network composed of poly(butyl acrylates) and poly(ethyl-hexyl acrylate)

International audienceNovel full acrylic interpenetrating polymer networks (IPNs) made up of thePoly Ethyl- Hexyl Acrylate (PEHA) and Poly Butyl-Acrylate (PABu) networkswith various crosslinking ratios were characterized by means of Infraredspectroscopy, swelling, DSC and TGA techniques. The systems are preparedvia photo-polymerization by UV-curing of monomers in the presence of adifunctional crosslinker and a photo-initiator. The physical properties of theIPNs are mainly influenced by the quantity of the monomer present in theIPNs and increasing the crosslinker prevents formation of unreactedoligomers inside the IPNs. Surprisingly, the IPNs with 0.5% crosslinker doesnot present any phase separation