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Browsing by Author "Ottati, Carolina"

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  • Biodegradation study of I lignin-based rigid polyrethane foams
    Publication . Lopretti, Mary; Cateto, Carolina; Barreiro, M.F.; Ottati, Carolina; Rodrigues, Alírio; Belgacem, Mohamed Naceur
    Polyurethanes are considered as one of the most versatile polymeric materials offering a wide range of products with applications in diverse sectors. Rigid polyurethane (RPU) foams belong to this class of products and represent a commercially important class of expanded materials. In the present work RPU foams have been prepared from lignin-based polyols (LP) obtained by oxypropylation of two technical lignins (Alcell and Indulin AT) and biodegradability evaluated using respirometry tests in liquid and solid media. A RPU foam produced from a commercial polyether polyol (CP) based on sorbitol (Lupranol® 3323) was used as reference. Lignin biodegradation by P. chrysogenum, T. harzianum, T. reesei, T. versicolor and P. chrysosporium fungi was tested. Respirometry tests (in liquid and solid media) were performed and foam’s biodegradation evaluated based on the produced CO2.
    2001Conference object Restricted access Show more
  • Lignin-based rigid polyurethane foams with improved biodegradation
    Publication . Cateto, Carolina; Barreiro, M.F.; Ottati, Carolina; Lopretti, Mary; Rodrigues, Alírio; Belgacem, Mohamed Naceur
    Rigid polyurethane (RPU) foams have been synthesized using lignin-based polyols obtained by oxypropylation of four distinct lignins (Alcell, Indulin AT, Curan 27-11P, and Sarkanda). Polyol formulations with two lignin/propylene oxide/catalyst content (L/PO/C) ratios were chosen (30/70/2 and 20/80/5). RPU foams have been prepared with a polyol component that incorporates the lignin-based one at contents ranging from 25 to 100%. A 100% commercial polyol-based (Lupranol! 3323) RPU foam was also prepared and used as the reference. RPU foams were characterized in terms of density, compressive modulus, and conductivity. Cell morphology and size estimation were accessed by scanning electron microscopy. Moreover, biodegradation of the Alcell- and Indulin AT-based foams was evaluated using respirometry tests in liquid and solid media. The Alcell- and Indulin AT-based polyols together with the 20/80/5 Curan 27-11P-based one led to RPU foams with properties quite similar to those of the reference homolog. Biodegradation seems to be, particularly, favored if using Indulin AT-based polyols mixed with Lupranol! 3323.
    2014Journal article Restricted access Show more