resumo
Rigid polyurethane foams (RPUFs) were synthesized using exclusively lignin-based polyol (LBP) obtained via the oxyalkylation of kraft lignin with propylene carbonate (PC). Using the design of experiments methodology combined with statistical analysis, the formulations were optimized to obtain a bio-based RPUF with low thermal conductivity and low apparent density to be used as a lightweight insulating material. The thermo-mechanical properties of the ensuing foams were compared with those of a commercial RPUF and a RPUF (RPUF-conv) produced using a conventional polyol. The bio-based RPUF obtained using the optimized formulation exhibited low thermal conductivity (0.0289 W/m center dot K), low density (33.2 kg/m(3)), and reasonable cell morphology. Although the bio-based RPUF has slightly lower thermo-oxidative stability and mechanical properties than RPUF-conv, it is still suitable for thermal insulation applications. In addition, the fire resistance of this bio-based foam has been improved, with its average heat release rate (HRR) reduced by 18.5% and its burn time extended by 25% compared to RPUF-conv. Overall, this bio-based RPUF has shown potential to replace petroleum-based RPUF as an insulating material. This is the first report regarding the use of 100% unpurified LBP obtained via the oxyalkylation of LignoBoost kraft lignin in the production of RPUFs.
palavras-chave
CRUDE GLYCEROL; MECHANICAL-PROPERTIES; THERMAL-CONDUCTIVITY; BLOWING AGENTS; POLYOLS; OXYALKYLATION
categoria
Polymer Science
autores
Vieira, FR; Gama, NV; Evtuguin, DV; Amorim, CO; Amaral, VS; Pinto, PCOR; Barros-Timmons, A
nossos autores
Ana Margarida Madeira Viegas de Barros Timmons
Professor associado
Carlos Amorim
Investigador Auxiliar
Dmitry Evtyugin
Professor Associado com Agregação
Fernanda Vieira
Colaborador
Vitor Brás Sequeira Amaral
Professor CatedráticoGrupos
G1 - Materiais Porosos e Nanossistemas
G2 - Materiais Fotónicos, Eletrónicos e Magnéticos
G4 - Materiais Renováveis e Economia Circular
G6 - Materiais Virtuais e Inteligência Artificial
Projectos
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
agradecimentos
This work was carried out under the Project Inpactus-innovative products and technologies from eucalyptus, Project No 21874 funded by Portugal 2020 through European Regional Development Fund (ERDF) in the frame of COMPETE 2020 no246/AXIS II/2017 and CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC).