Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid) oleh Jesús Manuel Quiroz-Castillo, Dora Evelia Rodríguez-Félix, Heriberto Grijalva-Monteverde, Lauren Lucero Lizárraga-Laborín, María Mónica Castillo-Ortega, Teresa del Castillo-Castro, Francisco Rodríguez-Félix, Pedro Jesús Herrera-Franco