Development of Polymeric Films Based on Gummy Plant Exudates and Natural Plant Fibers

Abstract This study addresses the fabrication of biodegradable polymeric films using gummy plant exudates from Euphorbia cotinifolia ("liberal rojo") and Euphorbia laurifolia ("lechero blanco") as the primary matrix, reinforced with Musa paradisiaca (plantain) and Guadua angustifolia (guadua bamboo) fibers. A solvent casting technique was employed to evaluate three formulations with varying exudate concentrations, using glycerol as a plasticizer, poly(vinyl alcohol) (PVA) as a crosslinking agent, and Tween 80 as an emulsifier. Formulation 2 (60% v/v exudate) exhibited superior mechanical performance, reaching a tensile strength of 9.52 MPa and an elongation at break of 416.52% in E. laurifolia films, significantly outperforming conventional biopolymers. Although natural plant fibers did not improve mechanical resistance due to weak interfacial adhesion with the matrix, they substantially enhanced moisture resistance. Biodegradation assays conducted under ISO 14855 and ASTM D 5988 standards confirmed high biological assimilation and mineralization of the material by soil microorganisms.