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Cellulose nano-biocomposites from high oleic sunflower oil-derived thermosets, DOI: 10.1016/j.eurpolymj.2016.04.018, Thiol-Michael addition of pentaerythritol tetrakis(3-mercaptopropionate) (PE3MP) to a high oleic sunflower oil derivative containing enone groups (ETG), has been used to prepare vegetable oil derived renewable thermosets in an efficient way and under mild conditions. The same formulation has been used to prepare nano-biocomposites by incorporating into the polymerization mixture, 1 wt%, 5 wt% and 10 wt% of cellulose nanocrystals (CNC) modified with Beycostat A B09® as surfactant. The chosen methodology allows a good dispersion of the nano filler in a low polarity reactive media which still is a challenging approach. The morphological, thermal and mechanical properties of the different nano-biocomposites were evaluated and compared with the pristine thermoset. Morphological analysis shows that good dispersion of the nanofillers is achieved in all formulations. Mechanical properties show an improvement of the Young Modulus for all nanofiller contents, showing a maximum at 5 wt% loading (32 and 78 MPa for the pristine and 5% CNC nano-composite respectively) that has been related with the reinforcement effect of the modified CNC. CNC dispersion also affects positively the surface properties, thus reducing drastically the contact angle values (78.0-16.0°for the pristine and 10% CNC nano-composite respectively). Finally, protein adsorption was measured in order to evaluate potential application of these materials as biosensors and cell growing supports.

Filiació URV: SI, An efficient route to obtain allyl- and propargyl-containing diols from 10-undecen-1-ol, and their polymerization with isophorone diisocyanate to produce alkene- and alkyne-functionalized polyurethanes (PUs) is described. The bio-based PUs have been further modified by thiol-ene/yne coupling of thioglycerol into unsaturation to obtain a series of PUs with enhanced hydrophilicity. All the synthesized PUs were characterized by FTIR-ATR and NMR spectroscopy. As expected, the PUs were amorphous and DSC revealed glass transition temperatures in the range of 40 °C¿5 °C for the PUs before and after modification. The PUs exhibited highly tunable thermal and mechanical properties. The mechanical properties of these bio-based polymers (E modulus from 774 MPa to 6 MPa and at break from 45% to 401%) make the suitable materials for a large range of applications.

Filiació URV: SI, An efficient route to obtain allyl- and propargyl-containing diols from 10-undecen-1-ol, and their polymerization with isophorone diisocyanate to produce alkene- and alkyne-functionalized polyurethanes (PUs) is described. The bio-based PUs have been further modified by thiol-ene/yne coupling of thioglycerol into unsaturation to obtain a series of PUs with enhanced hydrophilicity. All the synthesized PUs were characterized by FTIR-ATR and NMR spectroscopy. As expected, the PUs were amorphous and DSC revealed glass transition temperatures in the range of 40 °C¿5 °C for the PUs before and after modification. The PUs exhibited highly tunable thermal and mechanical properties. The mechanical properties of these bio-based polymers (E modulus from 774 MPa to 6 MPa and at break from 45% to 401%) make the suitable materials for a large range of applications.

Filiació URV: SIInclòs a la memòria: SI, Flame-retardant polybenzoxazine foams containing 1% phosphorus were prepared from diphenolic acid-based benzoxazine and 9,10-dihydro-9-oxa-10-(1-hydroxy-1-methylethyl)phosphaphenanthrene-10-oxide. Statistical predictive models were developed to determine the influence of the foaming time (tf) and foaming temperature (Tf) on the density, compressive modulus, and compressive strength of the foams. Results showed that the density of the foams exhibited great dependence on tf, whereas both compressive properties were more dependent on Tf and tf. Additionally, the flammability of the foams was also characterized by the limiting oxygen index. The presence of 9,10-dihydro-9-oxa-10-(1-hydroxy-1-methylethyl)phosphaphenanthrene-10-oxide greatly improved the flame retardancy of the resulting foams.