Corn and cassava starch with carboxymethyl cellulose films and its mechanical and hydrophobic properties

Katiany Mansur Tavares; Adriana de Campos; Milene Corso Mitsuyuki; Bruno Ribeiro Luchesi; José Manoel Marconcini

doi:10.1016/j.carbpol.2019.115055

Corn and cassava starch with carboxymethyl cellulose films and its mechanical and hydrophobic properties

Carbohydr Polym. 2019 Nov 1:223:115055. doi: 10.1016/j.carbpol.2019.115055. Epub 2019 Jul 20.

Authors

Katiany Mansur Tavares¹, Adriana de Campos², Milene Corso Mitsuyuki², Bruno Ribeiro Luchesi³, José Manoel Marconcini²

Affiliations

¹ Postgraduate Program in Biomaterials Engineering (PPGBiomat), Federal University of Lavras (UFLA), Lavras, Minas Gerais, Brazil. Electronic address: mansurtavares@yahoo.com.br.
² National Laboratory of Agribusiness Nanotechnology (LNNA), Embrapa Instrumentação, São Carlos, São Paulo, Brazil.
³ Postgraduate Program in Materials Science and Engineering (PPGCEM), Federal University of São Carlos (UFSCar), São Carlos, São Paulo, Brazil.

PMID: 31426991
DOI: 10.1016/j.carbpol.2019.115055

Abstract

The amylose and amylopectin content of starch influences its functional characteristics and its interaction with other materials. Thus, it is important to study the mechanical strength and hydrophilicity of starch films of different botanical origins to elucidate the influence of their constituents in the interaction with carboxymethyl cellulose (CMC). The objective of this work was to evaluate the mechanical and physico-chemical properties of corn and cassava starch films and their blends with CMC by casting. The addition of CMC improved the tensile, increasing the strength at 206% for its blends with corn starch and 51% for its blends with cassava starch, the rupture stress at 89% and 74%, respectively, and the rupture strain at 381% and 57%, respectively. The elastic modulus presented increase of 20% for corn starch/CMC and 18% for cassava starch/CMC and the water vapor permeability at 48 and 40%, respectively. The corn starch film was more hydrophobic due to its higher amylose content, which contributed to the interaction between starch and glycerol OH groups and CMC COOH groups. This interaction was evidenced by FTIR and contact angle analysis, turning corn starch/CMC films into less hydrophilic material and reducing its water vapor permeability rate, which made this material promising for several applications, including food packaging.

Keywords: Botanic source; Carboxymethylcellulose; Natural sources; Polymer packages; Starch.