No abstract

Diglycidyl ether Schiff base monomers were prepared from vanillin and various diamines. FT-IR, 1 H NMR, 13 C NMR, and mass spectroscopy were used to determine their structure. Cured thermoset epoxies made with them were compared to commercial epoxy in terms of mechanical properties. Tensile strengths ranged from 35.1 to 60.4 MPa, Young's modulus from 3.9 to 6.9 GPa, similar to the commercial product. The glass transition ranged from 80 to 117 C, the phase transition T α from 80 to 121 C and the storage modulus from 2 to 3.5 GPa. Thermogravimetric analysis showed that the vanillin-based epoxies were less heat resistant but had higher residual mass (20-30% wt/wt). Hydrolysis, hydrophobicity and degradation were also monitored to evaluate their potential for coating applications.

New thermoset composite material made from cardanol-based resin blended with microfibrillar cellulose was compared to petroleum-based vinyl ester and glass-fiber-reinforced unsaturated polyester in terms of mechanical, thermal, rheological and surface properties of produced polymers and composites. The bio-sourced material was less resistant than the commercial vinyl ester but comparable to the unsaturated polyester resin. Microfibrillar cellulose increased the tensile strength and modulus but increased the resin viscosity and decreased the mixture homogeneity. The bio-sourced and commercial resins displayed similar hydrophobic behavior, and cellulose slightly decreased composite hydrophobicity. The glass transition temperature of the bio-sourced material was comparable to that of the unsaturated polyester. Thermal decompositions of composites and thermoset polymers were also similar. Cellulose and cardanol thus may be adequate as sustainable components in the composite materials industry.

<div>By mimicking the cutin natural polyester networks of plant cuticles, we produced hydrophobic elastomers by a sustainable process, i.e., using a catalyst- and solvent-free polycondensation of glycerol and hydroxy fatty acids, two by-products of the agro-food industry. The hydroxy-fatty acid fraction was obtained by alkaline hydrolysis in ethanol of peels from industrial tomato pomaces. This industrial-like fatty acid fraction contained more than 90% wt. of 9(10)-16 dihydroxyhexadecanoic acid (diOHC16). The co46 polyesters were designed by increasing the ratio of esterified glycerol/diOHC16 in a range observed in plant cutins (up to 6% wt.). Their structure and functional properties (thermal, mechanical, gas permeability, interaction with bacterial cells) were characterized. Increasing the glycerol contents induced a significant decrease in the reticulation degree of the polyesters and the formation of crystalline domains with an hexagonal organization. These structural modifications were related to a marked increase of elastomeric extensibility (up to 217%). While water vapor permeability was not impacted, the increase of glycerol content induced a significant decrease of oxygen permeability. None of the polyesters displayed biocide activity, but an increase of glycerol content significantly reduced the adhesion of bacterial cells, potentially giving rise to antifouling applications. Finally, the increasing content of free hydroxyl groups of the co-polyesters offer opportunities of grafting and covalent substitution for tailored functionalization<br></div>