Exploiting poly(ɛ‐caprolactone) and cellulose nanofibrils modified with latex nanoparticles for the development of biodegradable nanocomposites

This study reports the development of nanocomposites based on poly(ɛ‐caprolactone) (PCL) and cellulose nanofibrils (CNF) modified with cationic latex nanoparticles. The physical adsorption of these water‐based latexes on the surface of CNF was studied as an environment‐friendly strategy to enhance the compatibility of CNF with a hydrophobic polymeric matrix. The latexes are composed of amphiphilic block copolymers based on cationic poly(N,N‐dimethylaminoethyl methacrylate‐co‐methacrylic acid) as the hydrophilic block, and either poly(methyl methacrylate) or poly(n‐butyl methacrylate) as the hydrophobic block. The simple and practical melt‐mixing of PCL‐ and latex‐modified CNF yielded white homogeneous nanocomposites with complete embedment of the nanofibrils in the thermoplastic matrix. All nanocomposites are semicrystalline materials with good mechanical properties (Young's modulus = 43.6–52.3 MPa) and thermal stability up to 335–340°C. Degradation tests clearly showed that the nanocomposites slowly degrade in the presence of lipase‐type enzyme. These PCL/CNF‐latex nanocomposite materials show great promise as future environmentally friendly packaging materials. POLYM. COMPOS., 40:1342–1353, 2019. © 2018 Society of Plastics Engineers