Effect of dibutyl itaconate on plasticization efficiency of a REX processed polylactide with peroxides

Abstract

This work reports the effect of a reactive extrusion (REX) process on polylactide (PLA) based formulations plasticized with dibutyl itaconate (DBI). As DBI contains a carbon-carbon double bond, it is suitable for reactive extrusion. REX was carried out in a co-rotating twin extruder with the addition of two different organic peroxides. The main aim of using REX during the blending of the DBI plasticizer with PLA is to improve the interaction between them so the obtained final properties of the formulations could be improved. Plasticization process allowed to improve the ductile properties of PLA, by using REX, an improvement on the tensile strength was obtained with a no remarkable change in ductility. The thermal characterization also revealed that the glass transition temperature Tg was reduced for all formulations including DBI. REX with DBI provided a slight increase in Tg and this effect was also evident in thermomechanical properties. Regarding the thermal degradation behaviour, the plasticizer reduced the onset degradation and the maximum degradation rate, while a slight improvement on thermal stability was observed by using REX with organic peroxides. Finally, plasticizer migration in water was observed in conventional extruded PLA/DBI formulations, while REX provided improved behaviour against migration.