Chemical and enzymatic depolymerizations of suberin isolated from potato peel (Solanum tuberosum var. Nikola) were performed under various conditions. Enzymatic hydrolysis with cutinase CcCut1 and chemical methanolysis with NaOMe of suberin yielded monomeric fragments, which were identified as TMS derivatives with GC-MS and GC-FID. The solid, hydrolysis-resistant residues were analyzed with solid state (13)C CP...
The preparation and characterization of biocomposite materials with improved properties based on poly(lactic acid) (PLA) and bacterial cellulose, and, for comparative purposes, vegetal cellulose fibers, both in their pristine form or after acetylation, is reported. The composite materials were obtained through the simple and green mechanical compounding of a PLA matrix and bacterial cellulose nanofibrils (or ve...
The use of trichloroacetyl isocyanate (TAI) to mark both hydroxyl and carboxyl groups borne by the hydrolysis or methanolysis of suberin fragments (a complex mixture of hydroxy fatty acids), allowed the quantitative assessment of the ratio between carboxyl and hydroxy groups, as well as the ratio between primary and secondary hydroxy groups, to be carried out reliably by (1)H nuclear magnetic resonance (NMR) sp...
A comparative study on the chemical composition of oak cork (Quercus suber L.) and corresponding industrial residues and birch (Betula pendula L.) outer bark is reported. Cork oak samples have lower extractives contents (6-9%) and higher contents of carbohydrates and lignin (23-27 and 33-38%, respectively) than those found for birch outer bark (40, 6 and 9%, respectively); suberin contents accounted for around ...
New nanocomposite films based on different chitosan matrices (two chitosans with different DPs and one water soluble derivative) and bacterial cellulose were prepared by a fully green procedure by casting a water based suspension of chitosan and bacterial cellulose nanofibrils. The films were characterized by several techniques, namely SEM, AFM, X-ray diffraction, TGA, tensile assays and visible spectroscopy. T...
Low-density polyethylene was filled with unmodified and fatty acid (hexanoic, dodecanoic, octadecanoic and docosanoic acids) esterified cellulose fibers. The thermal and mechanical properties, morphology and the water absorption behavior of the ensuing composites were investigated. The chemical modification of the cellulose fibers with fatty acids clearly improved the interfacial adhesion with the matrix and he...
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