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 (PLA REx ), 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 PLA REx 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, PLA REx 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 PLA REx PLA REx resulted in a better mechanical performance in the rubbery region (T > Tg PLA-phase ) due to the PA-µf morphology obtained.

Polylactid acid (PLA) is a biodegradable thermoplastic polymer that is presented as a good alternative to petroleum-derived plastics. Some of the major drawbacks of this material are its lack of thermal stability and rapid degradation in large-scale production, thus a special care must be put in the manufacturing processes involved. To improve their properties, a reactive extrusion with a multi-epoxy chain extender (SAmfE) has been performed at pilot plant scale. The induced topological modifications produce a mixture of several types of non-uniform structures.Conventional chromatographic (SEC-static light scattering) or spectroscopic (NMR-nuclear magnetic resonance) techniques usually fail in characterizing non-uniform structures. A method for the classification of modified PLA samples based on a multivariate treatment of the spectral data obtained by Fourier-transform infrared spectroscopy (FTIR) spectroscopy, jointly with the application of feature extraction and classification algorithms, has been applied in this study. The results of this work show the potential of the methodology proposed as a fast tool for process control.