The filtrate was dried under vacuum (200mbar) at 35C for 3h and then at 65C for 16h, and placed in a circular mold with a diameter of 80mm (the same diameter as the filter) and a thickness of 2mm. Compression molding was carried out at 195C for 10min using a hydraulic press (Fontjine, Netherlands) to apply a 6kN load to the preform during both heating and subsequent cooling. The resulting circular plaques weighed approximately 13g. For comparison, neat PLA preforms (P0) were produced by the same process, i.e. mixing with water, dewatering, drying and compression molding.