title: Effect of the addition order and amylose content on mechanical, barrier and structural properties of films made with starch and montmorillonite.
abstract: This study considered the effect of amylose content (30% and 70%), montmorillonite (MMT) fraction (5 and 15%) and preparation method on mechanical and barrier properties of starch/clay nanocomposites prepared by casting. In Method 1, (30% w/w) glycerol was incorporated before starch gelatinization and MMT addition, while in Method 2 after gelatinization and MMT addition. Nanocomposites with higher amount of MMT showed the highest tensile strength and Young's modulus for both preparation methods. Method 1 favored nanocomposite properties of films with less amylose content, meanwhile Method 2 favored nanocomposites properties with higher amylose content. Water vapor permeability did not decrease significantly in starch films with different amylose content with the two different preparation methods. X-ray diffraction of the starch films indicated intercalated structures. Higher melting temperature (Tm) was found for nanocomposites with Method 2, indicating more ordered structures. Films with 70% amylose content have higher Tm than films with 30% amylose.
authors.affiliation: Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Cerro Blanco No. 141, Col. Colinas del Cimatario, C.P. 76090 Santiago de Querétaro, QRO, Mexico; Centro de Desarrollo de Productos Bióticos del Instituto Politécnico Nacional, Km 8.5, Carretera Yautepec-Jojutla, Colonia San Isidro, Apartado Postal 24, 62731 Yautepec, MOR, Mexico.
authors.forename: C A
authors.initials: CA
authors.lastname: Romero-Bastida
authors.affiliation: Centro de Desarrollo de Productos Bióticos del Instituto Politécnico Nacional, Km 8.5, Carretera Yautepec-Jojutla, Colonia San Isidro, Apartado Postal 24, 62731 Yautepec, MOR, Mexico. Electronic address: labellop@ipn.mx.
authors.forename: L A
authors.initials: LA
authors.lastname: Bello-Pérez
authors.affiliation: Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Cerro Blanco No. 141, Col. Colinas del Cimatario, C.P. 76090 Santiago de Querétaro, QRO, Mexico.
authors.forename: G
authors.initials: G
authors.lastname: Velazquez
authors.affiliation: División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Iztapalapa, Apartado Postal 55-534, Iztapalapa D.F. 09340, Mexico.
authors.forename: J
authors.initials: J
authors.lastname: Alvarez-Ramirez
mesh_terms: D000688:Amylose / Q000737:chemistry*; D001546:Bentonite / Q000737:chemistry*; D055119:Elastic Modulus; D005990:Glycerol / Q000737:chemistry; D053761:Nanocomposites / Q000737:chemistry*; D013718:Tensile Strength
chemical_list: D001546:Bentonite; D000688:Amylose; D005990:Glycerol
keywords: Barrier; Films; Mechanical properties; Starch–clay composite