Effect of the Compatibiliser on the Poly(Lactic Acid)-Polyamide 11 Blends with and Without Metal Oxides: Properties,...

It can be argued that blends of biopolymers can be regarded as an economical and efficacious method for formulating blends with customised properties. In the context of immiscible and/or incompatible constituents, the use of a compatibiliser agent (i.e., physical or chemical compatibiliser) has been demonstrated to enhance specific properties, including ductility and hydrophobicity. In this study, biopolymer blends based on polylactic acid (PLA) and polyamide 11 (PA11), with and without a compatibiliser (ethylene butyl-acrylate glycidyl methacrylate; Elvaloy), and also in the presence of metal oxides, such as zinc oxide (ZnO) and titanium dioxide (TiO₂), were processed by melt mixing and characterised for their mechanical, rheological, thermal and hydrophobic behaviour, as well as for their photo-oxidation resistance. The presence of a compatibiliser appeared to have a beneficial effect on the system's ductility and hydrophobicity, also changing the blend morphology and reducing the dimensions of the PA11-droplets. The complex nature of the systems in question means that the beneficial effect of the compatibiliser on the dispersion of metal oxides cannot be fully appreciated. The favourable dispersion of metal oxide particles, in conjunction with their selective location at the interphase between the two polymeric phases and/or in the more polar phase, reduces the photo-oxidation resistance of these systems. This aspect must be given due consideration.