Glycerol with different purity grades derived from biodiesel: Effect on the mechanical and viscoelastic properties of biodegradable strands and films

The objectives of this work were to produce biodegradable films by blown extrusion containing glycerin obtained from biodiesel manufacturing as a plasticizer and to estimate the film characteristics using the mechanical and stress relaxation properties of the cylindrical strands. Three different purity grades of glycerin were investigated. Modified cassava starch, poly(butylene adipate co-terephthalate) and glycerin were utilized to produce the extruded cylindrical strands, and the pelletized strands were used to produce the films. Films with bi-distilled glycerin (BDG) as a plasticizer showed the highest elongation at break (438%) and the lowest Youngʹs modulus (50 MPa), and the viscoelastic properties of the strands produced with BDG showed the most viscous behavior. The elongation at break of the strands was not influenced by the degree of purity of the glycerin, and their viscoelastic properties were useful in predicting the behavior in the blown film production.