Biodegradable material based on starch-g-polyvinyl acetate copolymer with bactericidal properties

Biodegradable starch-based composite material with bactericidal properties was obtained in this work. The material is promising as environmentally safe food packaging. Native potato starch was modified by graft polymerization of vinyl acetate. The synthesis was carried out in the presence of ammonium persulfate in the alkaline medium under a temperature change mode from 70 to 80 °C. The grafting efficiency was 82% at 91, 5% conversion rate of vinyl acetate. The product of the synthesis is a homogeneous dispersion with an average particle size 2.2∙10–5 cm. The composition and chemical structure of Starch-g-PVAc copolymer were confirmed by extraction, IR spectroscopy and gel permeation chromatography. The films poured from copolymer solution are characterized by 24 MPa of breaking stress and 2.2% of strain. A copolymer-based composition with bactericidal properties was developed by introducing polyhexamethylene guanidine chloride. The composition is biodegradable. Biodegradation of the films under the action of mold fungus Aspergillus niger occurred by 96% in 28 days. The composite based on Starch-g-PVAc + PHMG-ch is promising for use in packaging, cleaning of water environment from contaminants, in medical applications.