Films of xylan/polyethylenimine with different mass ratios

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

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

In this work, the preparation of films from polyelectrolyte complexes (PECs) of xylan (extracted from sugar cane bagasse) and polyethyleneimine (PEI), was analyzed. PEI is a low-cost synthetic polymer used in the paper industry and in other fields. Different xylan/PEI mass ratios from 50/50 to 90/10, and two pH were considered, 5.0 and 7.0. Xylan solution was added onto PEI solution and the streaming current potential titration showed how the colloidal charge, originally cationic, was gradually reduced when complexes were formed. Charge was neutralized for a xylan content of 82 % and it was reversed to anionic for higher xylan addition. Under this anionic condition, the formation of a coacervate allowed the separation of up to 60 % of the volume as a supernatant. Stress at break of films was increased from 2.0 and 5.0 MPa (for pH 5.0 and 7.0, respectively) to 20.0 MPa when xylan content was increased from the 50 % to 90 %. Strain at break was decreased from 28 and 22 % to 2% but films were always handleable. The use the coacervate fraction to preparate films is beneficial for the reduction of the time and energy during the evaporation stage and allowed to remove part of the dissolved salts. Films prepared from coacervate showed the best stress at break (37.0 MPa) and a strain at break that is low (2%) but enough for film manipulation.