All‐Thermoplastic Poly(L‐Lactide)/Polyethylene Terephthalate Biocomposites in One Step Production by Thermoplastic Resin Transfer Molding: Manufacturing, Characterization and Mechanical Recycling

ABSTRACT To address environmental concerns, replacing thermoset matrices by thermoplastic ones has become a major focus in composite development. Biobased and industrially compostable polylactide, displaying good mechanical performances, is a matrix of choice to design biocomposites. This work reports the manufacturing of fully thermoplastic biocomposites combining poly(L‐lactide) (PLLA) matrix and polyethylene terephthalate (PET) fabrics via thermoplastic resin transfer molding (TP‐RTM) process through in situ L‐lactide polymerization catalyzed by tin (II) octoate. PLLA matrices, with L‐LA conversions up to 97%, displayed weight‐average molar masses over 140,000 g/mol. The resulting composites exhibited an impact strength up to 99 kJ/m ² , flexural strength of 141 MPa, and modulus of 4.7 GPa. Mechanically recycled plates with 5 wt% compatibilizer reached a Charpy impact strength of 14.7 kJ/m ² . To date, all‐thermoplastic composites have never been produced by TP‐RTM process. These new composites represent an unprecedented way to promote the development of eco‐friendly recyclable composite materials.