PLA/PA bio-blends: induced morphology by extrusion
PublisherMultidisciplinary Digital Publishing Institute (MDPI)
Rights accessOpen Access
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.
CitationGarcia, V. [et al.]. PLA/PA bio-blends: induced morphology by extrusion. "Polymers", 19 Desembre 2019, vol. 12, núm. 1, p. 10:1-10:22.
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