Grafting of poly(ε‐caprolactone) from Abaca cellulose fibers via ring‐opening polymerization resulting in facile one‐pot biocomposites

• Published in: SPE polymers 2021-10, Vol.2 (4), p.297-310
• Main Authors: Roy, Bernice Lorraine F., Heinrich, Lydia A., Tayo, Lemmuel L., Malmström, Eva, Engström, Joakim
• Format: Article
• Language: English
• Subjects: Abaca; Benzyl alcohol; biocomposites; Biodegradability; Biomedical materials; Cellulose fibers; Cellulosic resins; Chain entanglement; Composite materials; Disintegration; Entanglement; Grafting; Material properties; Molecular chains; one-pot synthesis; poly(ε‐caprolactone) (PCL); Polycaprolactone; Polymers; Rheological properties; Ring opening polymerization
• ISSN: 2690-3857; 2690-3857
• DOI: 10.1002/pls2.10058

As efforts to replace nonsustainable plastics increase, biocomposites from cellulose fibers and biodegradable polymers like poly(ε‐caprolactone) (PCL) are promising candidates. The necessary adhesion between fibers and matrix can be achieved by grafting polymeric chains onto the fibers. Herein, we report grafting of PCL onto Abaca fibers (AFs), a one‐pot method to obtain a composite containing grafted fiber and free PCL, and the characterization of prepared composite films. Three parameters for pretreatment (disintegration, drying, and solvent exchange) of AF were compared. Short and long PCL chains with molecular weights below and close to the chain entanglement weight of PCL were grafted from AFs. Using benzyl alcohol as an additional initiator, free PCL was simultaneously prepared. The unreacted monomer was removed by precipitation in water, resulting in ready‐made one‐pot composites. The biocomposites containing the free PCL and PCL‐grafted AFs were further processed by a combination of compounding and hot‐pressing. The analyzed mechanical (tensile) and rheological properties show a large dependence on the lengths of the PCL grafts. The herein‐reported composites pave the way for interesting bio‐based alternatives to plastic, especially looking at the tailoring of material properties. Ring‐opening Polymerization of ε‐caprolactone from Abaca cellulose fibers (pulp) and benzyl alcohol to make one‐pot composites by a facile water precipitation protocol.