Effects of ethanol on the size of xylan/chitosan micro/nanoparticles and on the mechanical properties of films

SCHNELL, CARLA N.; GALVÁN, MARÍA V.; YAMIL N. SOLIER; INALBON, MARÍA C.; ZANUTTINI MIGUEL A.; MOCCHIUTTI PAULINA

Coimbra

Conferencia; XXV Tecnicelpa International Forest, Pulp and Paper Conference / XI CIADICyP Iberoamerican Congress on Pulp and Paper Research (2021), Web International Conference; 2021

TECNICELPA/CIADICYP

Alkaline extractions of xylan (Xyl) from poplar wood were performed in a bench scale. The Xyl obtained was characterized, and used for preparing polyelectrolyte complexes by combining with another natural polymer, chitosan (Ch). The effects of the ethanol concentration (0; 3; 9; 12 and 16% wt.) on the characteristics of the polyelectrolyte complex suspensions (PECs) as well as on the properties of the films obtained were studied. PEC suspensions of 60 Xyl/40 Ch mass ratio were prepared at pH 5.0 using the dropwise addition method. Dynamic light scattering technique showed that particle sizes of PECs were decreased (from 1009 to 594 nm), and zeta potential values were increased (from +27 to +68 mV) when ethanol content was increased. Films were characterized by means of wet and dry mechanical properties, WVP and swelling. The stress at break of the washed films increased from 45 to 75 MPa when films were prepared in the presence of 12%wt. ethanol. The strain at break was similar for all films (approx. 6%). The wet-mechanical properties of all films were promising (5 MPa and 55 %). The WVP was not significantly changed, while the swelling capacity was slightly reduced due to the presence of ethanol.