The Portuguese industry is responsible for half of the production of cork.Worldwide, the annual amount of cork involved in the whole industry ascend to 300000 tonnes. This outstanding bio-composite, which is the external bark of Quercus suber L. possess a very interesting role of properties like elasticity, compressibility, low permeability of liquids and significant chemical/microbial resistance. The major components in cork are polysaccharides, “lignin-like” poly(phenolics) and suberin.This means that, structurally, cork has a strong relationship with lignocellulosic materials [1-3].
Since the liquefaction of biomass for other application like fuel, foams, adhesives and other materials are being study as an alternative for petroleum derived products, we envisaged to exploit this biomaterial as a source of raw material for liquefaction.
Cork residues were subjected to liquefaction under acidic medium, being a dark brownish crude obtained. Conversions rates higher than 90% were obtained depending on the catalyst and solvents used as well as with different temperatures and reaction time. Ultrasounds and microwaves were helpful in the decrease of the time consumed for the liquefying process. The polyols, derived from the depolymerization of polysaccharides, were extracted after multiple extractions of the reaction crude leading to a yellow oil which is being use to develop newly natural-based polymeric materials for a wide range of applications.
The first studies conducted for the liquefaction of Portuguese cork in acidic medium comprising the results obtained for different solvents, catalysts, pre-treatment and other reaction parameters will be presented.
Acknowledgements
The authors acknowledge QREN financial support and cork material provided by Cork Suply.
References
[1] P Jové, MA Olivella and L Cano, BioResources 6 (2011) 1806.
[2] MH Lopes, A.S. Barros, CPNeto, D Rutledge, I Delgadillo and AM Gil, Biopolymers 62 (2001) 268.
[3] N Cordeiro, NM Belgacem, A Gandini and CP Neto, Bioresour. Technol. 63 (1998) 153.
