Flexural Moduli of Vapor-Grown Carbon Nanofiber/Woodflour/Polypropylene Composites

摘要

Vapor-grown carbon nanofibers (CNF) (60 to 230 nm diameters, 5 to 70 μm lengths) and southern pine wood flour (WF) (80 to 100 mesh) were compounded into polypropylene (PP) matrices at 190°C in a Bra-bender to form novel hybrid fiber composites. From 0.61 to 4.8 wt% of CNF and 16 to 37.5 wt% WF were employed. Maleated polypropylene (MAPP) was used to improve WF to matrix compatibility. Samples were compression molded at 190°C and 1.5 MPa. Flexural moduli was obtained by four-point bending tests. Both CNF and WF enhanced the moduli with small amounts of CNFs having large stiffness enhancing effects. Pure PPs modulus (3394 MPa) increased 24 percent to 4943 MPa by the addition of 0.99 wt% CNF and 39.4 percent to 5352 with 4.7 wt% CNF without MAPP addition. WF (16.3% and 28.0%) raised the moduli 54 percent and 66 percent to 6157 and 6636 MPa, respectively, when MAPP was present. The presence of 36.8 percent WF in combination with 0.61 wt% (～0.3 vol.%) and MAPP gave a modulus of 7590 MPa (90% enhancement vs. PP).