Novel lightweight foamed poly(lactic acid) reinforced with different loadings of functionalised Sepiolite

The aim of the present work is to develop an ease processable novel biobased lightweight material with improved mechanical and thermal properties. Sepiolite was used as reinforcement to improve Poly lactic acid (PLA) mechanical properties. Composite materials were obtained by extrusion and injection moulding. A chemical foaming agent (CFA) was introduced at 2 wt.% not only to produce a foamed polymer but also to ease the processability of the material. The obtained results demonstrated that Sepiolite improves PLA mechanical properties and makes the composite thermically more stable. The combination of CFA and Sepiolite favours nucleation during the foaming process and therefore the homogeneous formation of microporosity. The appropriate combination leaded to a decrease in density of 33% respect to raw PLA with improved mechanical properties attaining a material 9% stiffer with 10 wt.% Sepiolite and 38% tougher with just 2 wt.% of Sepiolite.