Different approaches to obtain poly(lactic acid) based compounds for semidurable applications

Abstract

This thesis aims to expand the current scientific knowledge concerning polylactide and the different approaches which could lead to get over its limiting properties, i.e.: brittleness and thermal resistance; and the measurement of their lifespan in order to evaluate their use in semidurable or durable applications. For this purpose, blends of PLA with PMMA have been prepared at different ratios by twin screw extrusion. Moreover, the properties of the most interesting blend have been subsequently studied by Reactive Extrusion in the presence of a styrenic-glycidyl acrylate copolymer. On the other hand, a deep study concerning the combinational effect of plasticizer and nucleating agents on the crystallization kinetics of PLAs with different L-lactic acid contents was carried out. Finally, the lifespan predictions of the most interesting compounds developed was carried out. It has been experimentally measured the effect of ageing on the mechanical properties of the compounds, carried out by accelerated ageing at high temperatures.