Biodegradable Green Composites from Distiller's Dried Grains with Solubles (DDGS) and a Polyhydroxy(butyrate-co-valerate) (PHBV)-Based Bioplastic

Biodegradable green composites from distiller's dried grains with solubles (DDGS), a major coproduct of the corn ethanol industry, and a polyhydroxy(butyrate-co-valerate) (PHBV)-based bioplastic were successfully produced. Green surface treatment of DDGS was performed and thermogravimetric analysis showed noticeable improvement in the degradation onset temperature of DDGS from 140 to 235 degrees C; this was a key point during melt processing of the composite. Utilizing compatibilizer improved the adhesion between DDGS and the matrix, which was observed by scanning electron microscopy. The green composite containing treated and compatibilized DDGS showed an enhanced modulus (by about 28% from 1.77 to 2.26 GPa) and an improved heat deflection temperature (by about 21% from 109 to 132 degrees C) compared to the polymeric matrix, while having tensile and flexural strengths equal to or greater than the respective properties of the matrix.