Polyethylene naphthalate single-polymer-composites produced by the undercooling melt film stacking method

High performance recyclable polyethylene naphthalate (PEN) single-polymer-composites (SPCs) were successfully produced by using the undercooling melt film stacking method within 220–260 °C. A significant large processing temperature window (48 °C) was determined by differential scanning calorimetry. The tensile properties of the PEN SPCs as a function of compaction temperature and holding time were studied. As the compaction temperature increased, the tensile strength increased first and then decreased. Similar trend was observed as the holding time increased. In order to obtain the best tensile property, a longer holding time is needed when the compaction temperature is lower. A tensile strength of 224 MPa and a tensile modulus of 8.4 GPa were achieved at an optimum processing condition, compaction temperature of 240 °C and holding time of 10 min. The tensile strength of the PEN SPCs was 3.6 times higher than that of the non-reinforced PEN. Scanning electron microscopy showed good interfacial adhesion between fibres and matrix.