Tung oil-based coatings towards sustainable paper packaging materials

resumo

Nowadays, the dependence on synthetic plastic-based materials for the preservation and transport of different types of products is very high, leading to major environmental and human health concerns, which highlights the importance of investigating sustainable options. Paper is a widely used bio-based material for packaging how-ever, the development of newer and straightforward approaches to produce paper-based materials with increased functionalities and performance is still highly desired. In this work, we report the use of a bio-based photo-polymerizable coating formulation, composed of tung oil, and using Darocur 1173 as photoinitiator, to develop functional papers with hydrophobic and improved water barrier properties, without compromising other properties. Coated paper samples were prepared, using different irradiation times (0, 15, 30, 60, and 300 s), to study the effect of this parameter on the properties of the coated papers. The ensuing coated papers presented pick-up values between 6 and 7 g/m2. Their hydrophobicity was significantly improved as evidenced by the increase in the contact angle values from about 71 degrees to 127 degrees and the significant decrease in the water absorption, measured by the Cobb test, from 108 down to 17 g/m2, upon a curing time of only 15 s. Furthermore, with this time of curing, the optical (viz. whiteness, brightness, and opacity) and mechanical properties (viz. tensile and burst strength) of paper were not affected. These results highlight the great potential of tung oil photo-polymerizable coating formulations as a simple and promising alternative for the fabrication of more sustainable and functional paper packaging materials.

palavras-chave

BIO-BASED COATINGS; CELLULOSE; POLYMERS; BARRIER

categoria

Chemistry; Materials Science

autores

Silva, FM; Pinto, RJB; Barros-Timmons, AM; Freire, CSR

Grupos

G1 - Materiais Porosos e Nanossistemas
G4 - Materiais Renováveis e Economia Circular

Projectos

InPaCTus - Innovative Products and Technologies from Eucalyptus Project (InPacTus)

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

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 n ? 246/AXIS II/2017. The research contract of R.J.B. Pinto was funded by national funds (OE) , through FCT in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree -Law 57/2016, of August 29, changed by Law 57/2017, of July 19. This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC) . FCT is also acknowledged for the research contract under Scientific Employ- ment Stimulus to C.S.R.F. (CEECIND/00464/2017) .