Oat Fiber as Reinforcement for Starch/Polyvinyl Alcohol Materials Produced by Injection Molding

• Published in: Starch - Stärke Vol. 70; no. 7-8
• Main Authors: Zanela, Juliano, Bilck, Ana P., Casagrande, Maira, Grossmann, Maria V. E., Yamashita, Fabio
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.07.2018
• Subjects: Alcohols; Biodegradability; Biodegradable materials; biodegradable polymers; Biodegradation; Cassava; cationic starch; Cations; composites; Elongation; Fibers; Formulations; Glycerol; Injection; Injection molding; Material properties; Mechanical properties; Modulus of elasticity; Polyvinyl alcohol; Starch; Starches
• ISSN: 0038-9056; 1521-379X
• DOI: 10.1002/star.201700248

The use of low‐cost natural fibers is an interesting alternative to both improve the mechanical properties and reduce the cost of biodegradable materials. Oat fibers are studied as reinforcer or filler in starch/PVA biodegradable materials produced by an injection molding process, using native and cationic cassava starches. The formulations contain 45 wt% of starch + fiber, 25 wt% of PVA, and 30 wt% of glycerol, and the oat fiber proportions are 0, 2.5, 5.0, 7.5, and 10.0 wt%. All materials have good processability, and the tensile strength, Young's modulus, and elongation at break range from 4.7 to 5.5 MPa, 7.1–12.4 MPa, and 180–260%, respectively. The type of starch (native or cationic) does not influence the biodegradable material properties. The oat fiber presents a good dispersion and compatibility with the polymeric matrix, acting mainly as a filler, reducing the material costs. Oat fiber is incorporated in starch/polyvinyl alcohol biodegradable materials produced by injection molding. Native and cationic starch are used, and both of them present good dispersion and compatibility with oat fibers. The oat fibers act mainly as a filler, reducing the material costs without disadvantageous changes to the properties. At the same time, oat fiber incorporation promotes a darkening in the color of the biodegradable materials.