Enhanced thermal and mechanical properties of epoxy composites by addition of hyperbranched polyglycerol grown on cellulose fibers

We reported a novel approach for epoxy composites by incorporation of hyperbranched polyglycerol (HPG) grafted sisal cellulose fibers (SCF). In this work, we have synthesized SCF wrapped HPG shell (SCF-g-HPG) by a “grafting from” strategy for the strong interfacial interaction between fillers and matrix. It was found that the thermal and mechanical properties of epoxy composites were greatly improved by incorporating SCF-g-HPG. For example, the impact strength, flexural strength, tensile strength, Young’s modulus and toughness of the composites with 3.0 wt% SCF-g-HPG loading were 38.35 KJ/m², 123.40 MPa, 86.62 MPa, 151.7 MPa, and 417.84 MJ/m³, significantly increased by 119.1 %, 55.2 %, 45.6 %, 43.1 %, and 166.1 % respectively, as compared with neat epoxy. In addition, thermal stability of SCF-g-HPG/epoxy composites also showed an obvious enhancement compared with neat epoxy.