Polymer–Polymer and Single Polymer Composites Involving Nanofibrillar Poly(vinylidene Fluoride): Manufacturing and Mechanical Properties

Nanofibrillar polymer–polymer composites (NFCs) and single polymer composites (SPCs) were produced using linear low density polyethylene (LLDPE) and poly(vinylidene fluoride) (PVDF). The NFCs were fabricated by means of a microfibrillar composite concept comprising melt blending, cold drawing, and compression molding retaining the highly oriented PVDF reinforcing nanofibrils (diameter of approximately 250 nm) dispersed without any agglomeration in the isotropic LLDPE matrix. The SPC films were prepared by partial surface premelting of neat PVDF nanofibrils (diameter of about 130 nm) using hot compaction at 148°C (about 20°C below the complete melting of PVDF), thus preserving the PVDF nanofibrillar identity. Tensile testing of NFCs based on LLDPE and PVDF showed an increase in the tensile modulus by 135% and in the tensile strength at break by 211%, as compared to those of an isotropic LLDPE film. Furthermore, the PVDF SPCs showed an enhancement of tensile modulus of 30% and strength at break of 305% when compared to those of an isotropic PVDF film.