Sericin as compatibilizer in starch/ polyester blown films

• Main Authors: Patrícia Salomão Garcia, Franciele Rezende Barbosa Turbiani, Alessandra Machado Baron, Guilherme Luiz Brizola, Mariane Alves Tavares, Fabio Yamashita, Daniel Eiras, Maria Victória Eiras Grossmann
• Format: Article
• Language: English
• Published: Associação Brasileira de Polímeros 2018-11-01
• Series: Polímeros
• Subjects: biodegradable packaging; compatibilization; extrusion; poly(butylene- adipate-co-terephthalate)
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-14282018005006106&lng=en&tlng=en

Abstract This study investigated the effects of low concentrations of sericin (≤ 1.5 wt%) in starch- poly(butylene-adipate-co-terephthalate) (PBAT) films. The films were produced by blown extrusion and mechanical, barrier and structural properties were determined. Films containing 1.0 and 1.5 wt% sericin showed higher tensile strength (6.41 and 6.59 MPa) and Young's modulus (90.88 and 132.71 MPa) compared with film without sericin (4.76 MPa and 18.64 MPa). When 0.5 wt% of sericin was used, the elongation was reduced by 62%. The addition of sericin in a concentration of 1.5% (w/w) decreased the water vapor permeability of films from 7.55 to 5.94 g (m s Pa)-1, likely due to the formation of a more homogeneous and compact matrix. Based on these results, a mechanism of action is proposed, whereby sericin acts at the interface of the polymers (starch and PBAT), reducing the interfacial tension and enhancing compatibility.