Key Improvements in Interfacial Adhesion and Dispersion of Fibers/Fillers in Polymer Matrix Composites; Focus on PLA Matrix Composites

No doubt, composite technology is fast growing with an increase in research efforts around the world and with many academic interests consisting of breath-taking innovations in polymer science. Herein, the primary determinants of fiber/filler-matrix/composite properties are discussed viz-a-viz dispersion of reinforcing fibers, interfacial adhesion between matrix/fibers, and surface treatment methods for fibers in composite fabrication. Both thermoplastic and thermoset composites are discussed with much-focused discussion on the biodegradable and environmentally friendly PLA polymer matrix adhesion with filler/fibers. Since achieving enhanced mechanical properties of both thermoset and thermoplastic matrices involves reinforcement with both micro and nanofiller and, in many cases, with natural fibers, addressing the major issue of compatibilising the hydrophilic fiber with the hydrophobic polymer becomes more imperative. Beginning the discussion with a brief on adhesion and its mechanisms with polymer/matrix interaction, it further looked at key surface modification techniques with organic acids to promote dispersion in organic solvents and hydrophobic polymers to enhance interfacial adhesion. The last section offered recommendations with regards to 100% green composite system, with the possibility of achieving fiber/matrix compatibility with zero chemical consumption and fabrication of new materials whose properties are compatible without coupling and surface treatment of reinforcing fibers.