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PLA/PA Bio-Blends: Induced Morphology by Extrusion

2019; Multidisciplinary Digital Publishing Institute; Volume: 12; Issue: 1 Linguagem: Inglês

10.3390/polym12010010

2073-4360

Violeta García-Masabet, Orlando Onofre Santana Pérez, Jonathan Cailloux, Tobias Abt, Miguel Sánchez‐Soto, F. Carrasco, Ma Lluïsa Maspoch Rulduà,

Polymer Foaming and Composites

The effect of processing conditions on the final morphology of Poly(Lactic Acid) (PLA) with bio-based Polyamide 10.10 (PA) 70/30 blends is analyzed in this paper. Two types of PLA were used: Commercial (neat PLA) and a rheologically modified PLA (PLAREx), with higher melt elasticity produced by reactive extrusion. To evaluate the ability of in situ micro-fibrillation (μf) of PA phase during blend compounding by twin-screw extrusion, two processing parameters were varied: (i) Screw speed rotation (rpm); and (ii) take-up velocity, to induce a hot stretching with different Draw Ratios (DR). The potential ability of PA-μf in both bio-blends was evaluated by the viscosity (p) and elasticity (k’) ratios determined from the rheological tests of pristine polymers. When PLAREx was used, the requirements for PA-μf was fulfilled in the shear rate range observed at the extrusion die. Scanning electron microscopy (SEM) observations revealed that, unlike neat PLA, PLAREx promoted PA-μf without hot stretching and the aspect ratio increased as DR increased. For neat PLA-based blends, PA-μf was promoted during the hot stretching stage. DMTA analysis revealed that the use of PLAREx PLAREx resulted in a better mechanical performance in the rubbery region (T > Tg PLA-phase) due to the PA-μf morphology obtained.