Preparation of poly‐d,l‐lactide based nanocomposites with polymer‐grafted silica by melt blending: Study of molecular, morphological, and mechanical properties

• Published in: Polymer composites Vol. 42; no. 2; pp. 955 - 972
• Main Authors: Régibeau, Nicolas, Tilkin, Rémi G., Grandfils, Christian, Heinrichs, Benoît
• Format: Journal Article Web Resource
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.02.2021; Blackwell Publishing Ltd; Wiley
• Subjects: aliphatic polyesters; Chemical engineering; Chemistry; Chimie; Engineering, computing & technology; Grafting; grafting from; grafting to; Ingénierie chimique; Ingénierie, informatique & technologie; Materials science & engineering; Mechanical properties; Melt blending; Modulus of elasticity; Nanocomposites; Nanoparticles; Physical, chemical, mathematical & earth Sciences; Physique, chimie, mathématiques & sciences de la terre; poly-D,L-lactide; Polylactic acid; Polymers; Ring opening polymerization; Science des matériaux & ingénierie; Silicon dioxide; Sol-gel processes; Tensile stress
• ISSN: 0272-8397; 1548-0569; 1548-0569
• DOI: 10.1002/pc.25878

Polylactide was first designed for the pharmaceutical and medical fields. Unfortunately, polylactide, especially poly‐d,l‐lactide (PDLLA), presents too low mechanical properties for a wide range of applications. The addition of silica nanoparticles should reinforce the mechanical strength of PDLLA. In order to improve silica/polymer interactions, this study focused on the preparation of polymer chain grafted silica using two grafting methods. The first strategy relied upon the ring opening polymerization of d,l‐lactide on initiating silica surface (ie, “grafting from”). The second approach considered a sol‐gel synthesis process in presence of Si‐OR terminated polylactide chains to promote grafting of these chains on new silica particles (ie, “grafting to” method). Only “grafting from” silica successfully led to a nanoscale dispersion into the polyester matrix for silica content up to 5 wt%. A 3 wt% content of this silica allowed improving Young modulus of 106.0% and ultimate tensile stress of 63.7% compared to the PDLLA control. The purpose of this article was to graft polymer chains at the silica surface to increase silica/polymer matrix interaction. Thanks to the polymer chain grafting, dispersion of silica and composite mechanical properties were highly improved.