title: Biodegradable and non-retrogradable eco-films based on starch-glycerol with citric acid as crosslinking agent.
abstract: Biodegradable and non-retrogradable starch-glycerol based films were obtained using citric acid (CA) as crosslinking agent at 75°C. This material allowed decreasing water vapor permeability (WVP) more than 35%, remained amorphous for at least 45 days as a result of the network formed by the CA that avoided starch retrogradation and maintained the degradability in compost, occurring only six days after the films without citric acid. A simulation of the gelatinization process of starch-glycerol with and without CA, using a differential thermal analysis device, showed that the system with CA completed the gelatinization 5°C before than the other and, CA first reacted with glycerol and then starch-glycerol-CA reaction occurred. The temperature at which the gelatinization process was carried out was critical to obtain the best results. An increase of gelatinization process temperature at 85°C in system with CA, led to a worsening on WVP and its integrity after a swelling process with dimethylsulphoxide (DMSO), compared to the films processed at 75°C.
authors.affiliation: LP&MC, Dep. de Física-IFIBA (CONICET), FCEyN, UBA, Ciudad Universitaria, 1428 CABA, Argentina.
authors.forename: Paula González
authors.initials: PG
authors.lastname: Seligra
authors.affiliation: Instituto de Tecnología en Polímeros y Nanotecnología ITPN (UBA-CONICET), FCEyN, UBA, Av. Las Heras 2214, C1127AAQ, CABA, Argentina.
authors.forename: Carolina
authors.initials: C
authors.lastname: Medina Jaramillo
authors.affiliation: LP&MC, Dep. de Física-IFIBA (CONICET), FCEyN, UBA, Ciudad Universitaria, 1428 CABA, Argentina.
authors.forename: Lucía
authors.initials: L
authors.lastname: Famá
authors.affiliation: LP&MC, Dep. de Física-IFIBA (CONICET), FCEyN, UBA, Ciudad Universitaria, 1428 CABA, Argentina. Electronic address: goyanes@df.uba.ar.
authors.forename: Silvia
authors.initials: S
authors.lastname: Goyanes
mesh_terms: D001673:Biodegradation, Environmental; D019343:Citric Acid / Q000737:chemistry*; D003432:Cross-Linking Reagents / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D005990:Glycerol / Q000737:chemistry*; D010539:Permeability; D012988:Soil Microbiology; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry; D014867:Water / Q000737:chemistry
chemical_list: D003432:Cross-Linking Reagents; D014867:Water; D019343:Citric Acid; D013213:Starch; D005990:Glycerol; D004121:Dimethyl Sulfoxide
keywords: Biodegradability; Biodegradable edible films; Citric acid; Crosslinking; Starch