Abstract: As a biodegradable material， PLA has poor impact toughness， resulting in a limitation of application. To address this problem， there have been many elastomer-filling schemes proposed for the toughening of PLA； however， most of these schemes cause the strength loss of PLA or the introduction of non-degradable components as compatibilizers. In this case， we developed a new processing method to solve this problem through filling PBAT and processing with a tri-screw extruder combined with cold-pressing with a roll-to-roll machine. Through the characterization of the compounding samples prepared with this processing method， there was an elongation effect of the roll-to-roll cold-pressing process on PBAT as observed from the SEM image， and the in-situ fibrillation induced by the elongation effect was noted. Meanwhile， the experimental results indicated that the elongation effect promoted the crystallization of PLA. The tensile experiments proved that the in-situ fibrillation and crystalline improvement played a role in the toughening and strengthening of PLA. The influence of this processing method on the thermal stability of the compounding samples was also evaluated through thermogravimetric analysis， and its toughening mechanism was analyzed. This work may provide a new methodology for the toughening of PLA.

Key words: poly（lactic acid）, toughening, cold-pressing, in-situ fibrillation, improvement of crystallization