<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cordeiro, N</style></author><author><style face="normal" font="default" size="100%">Belgacem, M N</style></author><author><style face="normal" font="default" size="100%">Gandini, A</style></author><author><style face="normal" font="default" size="100%">Neto, C P</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Urethanes and polyurethanes from suberin 2: synthesis and characterization</style></title><secondary-title><style face="normal" font="default" size="100%">INDUSTRIAL CROPS AND PRODUCTS</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">glass transition</style></keyword><keyword><style  face="normal" font="default" size="100%">polyurethanes</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus suber L.</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal properties</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><publisher><style face="normal" font="default" size="100%">ELSEVIER SCIENCE BV</style></publisher><pub-location><style face="normal" font="default" size="100%">PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS</style></pub-location><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">1-10</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Polyurethanes based on suberin from cork of Quercus suber L. and conventional isocyanate monomers were prepared and fully characterized in terms of both structure (FTIR and H-1 NMR spectroscopy) and thermal properties (differential scanning calorimetry and thermogravimetric analysis). Two fractions were systematically isolated, namely (i) methylene-chloride soluble products, which corresponded to linear and branched macromolecules and (ii) methylene-chloride insoluble products, representing the crosslinked material. The structures of these polymers were regular and no appreciable side reactions were detected. DSC analyses provided information about the glass transition temperature of both fractions and this parameter was correlated with the stiffness of the isocyanate used. The TGA of these polyurethanes showed that they started to degrade at about 175 degrees C and that the residue at 400 degrees C was around 50%. The highest amounts of insoluble fractions, as well as the highest T-g,s, were reached when an initial \{[\}NCO]/\{[\}OH] of unity was used. (C) 1999 Elsevier Science B.V. All rights reserved.</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Cordeiro, N</style></author><author><style face="normal" font="default" size="100%">Belgacem, N M</style></author><author><style face="normal" font="default" size="100%">Gandini, A</style></author><author><style face="normal" font="default" size="100%">Neto, C P</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Cork suberin as a new source of chemicals: 2. Crystallinity, thermal and rheological properties</style></title><secondary-title><style face="normal" font="default" size="100%">Bioresource technology</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Alkaline methanolysis</style></keyword><keyword><style  face="normal" font="default" size="100%">cork of Quercus suber L.</style></keyword><keyword><style  face="normal" font="default" size="100%">crystallinity</style></keyword><keyword><style  face="normal" font="default" size="100%">Density</style></keyword><keyword><style  face="normal" font="default" size="100%">rheological properties</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword><keyword><style  face="normal" font="default" size="100%">thermal characterization</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year></dates><volume><style face="normal" font="default" size="100%">63</style></volume><pages><style face="normal" font="default" size="100%">153-158</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Suberin samples, obtained by alkaline methanolysis from cork (Quercus suber L.), were submitted to various physical characterizations; DSC, TGA, optical microscopy, density and rheological properties. A sub- stantial proportion of these oligomers possessed a microcrystalline character with a melting range between 0 and 50°C. The amorphous part was liquid at room temperature and did not display a detectable glass transition upon cooling because of its wide molecular weight distribution. The viscous behaviour of suberin at room temperature was both plastic and thixotropic because of the structuring role of the micro- crystals</style></abstract></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Neto, C P</style></author><author><style face="normal" font="default" size="100%">Cordeiro, N</style></author><author><style face="normal" font="default" size="100%">Seca, A</style></author><author><style face="normal" font="default" size="100%">Domingues, F</style></author><author><style face="normal" font="default" size="100%">Gandini, A</style></author><author><style face="normal" font="default" size="100%">Robert, D</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Isolation and characterization of a lignin-like polymer of the cork of Quercus suber L.</style></title><secondary-title><style face="normal" font="default" size="100%">HOLZFORSCHUNG</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Cork</style></keyword><keyword><style  face="normal" font="default" size="100%">lignin-like polymer</style></keyword><keyword><style  face="normal" font="default" size="100%">Quercus Suber L</style></keyword><keyword><style  face="normal" font="default" size="100%">suberin</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1996</style></year></dates><publisher><style face="normal" font="default" size="100%">WALTER DE GRUYTER &amp; CO</style></publisher><pub-location><style face="normal" font="default" size="100%">GENTHINER STRASSE 13, D-10785 BERLIN, GERMANY</style></pub-location><volume><style face="normal" font="default" size="100%">50</style></volume><pages><style face="normal" font="default" size="100%">563-568</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">A lignin-like polymer was successfully extracted from the cork of Quercus suber L. using an organosolv-based technique. This material was characterized by elemental analysis, functional group analysis, nitrobenzene oxidation followed by HPLC analysis of the oxidation products, FTIR and liquid C-13 NMR. The evidence thus obtained indicated that the extracted material was composed mainly of a lignin-like polymer covalently bound to residual aliphatic structures which are not present in common lignins and which have been assigned to suberin. The latter is likely to be attached to the oxygenated side chains of the phenolic polymer but bonding through the aromatic ring can also be envisaged. No residual carbohydrates were detected. The phenolic polymer, composed mainly of guaiacyl-type units and small amounts of syringyl-type units, had a low methoxy content and a high degree of condensation. This polymer showed the presence of a fraction containing C6Cn units with n &lt; 3 or even n &lt; 2.</style></abstract></record></records></xml>