Thermoplastic starch–lignosulfonate blends. 1. Factorial planning as a tool for elucidating new data from high performance size-exclusion chromatography and mechanical tests

Blends of cornstarch, glycerol and lignosulfonate were prepared in variable-speed batch mixer at 150–160 °C, with the glycerol in various proportions from 20 to 40% and lignosulfonate from 10 to 40%. Alterations in HPSEC chromatogram profiles after the thermal processing were analyzed. sults showed that an increase in glycerol preserves the starch chains from degradation, which occurs to a smaller extent in samples without both lignosulfonate and modified lignosulfonate. chers have attributed the degradation of the starch compounds to shear-induced fragmentation, which increases the viscosity of the starch–glycerol matrices. Applying factorial planning at two levels, it was possible to obtain equations that better represent the effects caused by the presence of glycerol and lignosulfonate in the thermoplastic matrices. fect of using hydroxymethylated lignosulfonate on the mechanical properties of starch was also investigated.