Plywood of northeast Argentinian woods and cardanol-based adhesives

E. NICOLAO; S. MONTEOLIVA; E. CIANNAMEA; P.M. STEFANI

Buenos Aires

Congreso; WCCE- 11th WORLD CONGRESS OF CHEMICAL ENGINEERING 2023; 2023

UBA

The feasibility of using cardanol-based biogenic adhesives as a substitute for synthetic phenolic adhesives in the production of eucalyptus grandis plywood was evaluated. Cardanol, which is obtained by decarboxylation and distillation of the inedible viscous liquid present between the shell and the cashew nut, was used as a sustainable platform for obtaining biobased epoxy resin and amine curing agents. These systems allow obtaining thermosetting adhesives at relatively low pressing temperatures. The production of plywood requires adhesives with glass transition temperature (Tg) values higher room temperature in order to maintain their structural integrity. However, cardanol-based adhesives exhibited Tg values of 20 °C due to their low crosslinking density inherent to their chemical structure. To overcome this drawback, the biogenic epoxy monomer was partially substituted in stoichiometric amounts by a synthetic epoxy resin. The results indicated that for 60% substitution the adhesives reached a Tg value of 47 °C. The plywood boards made with this adhesive formulation, with a high content of biogenic component, met the gluing quality requirements established by IRAM 9562 for protected or occasional wet environments.Acknowledgments: The authors wish to express their gratitude to ANPCyT, grant number PICT 2020 1003, to CONICET (PIP2021-2023 N°0926) and to the Universidad Nacional de Mar del Plata, UNMdP, Argentina.