[Effect of moulding and extruding conditions on mechanical properties of poly(D,L-lactide) and MDI chain-extending poly(D,L-lactide)/hydroxyapatite composite]

Abstract

In this paper, poly(D,L-lactide) (PDLLA), MDI chain-extending poly(D,L-lactide) (PDLLA/MDI) and MDI chain-extending poly(D,L-lactide)/hydroxyapatite composite (PDLLA/HA/MDI) were prepared respectively and the effects of moulding and extruding conditions on their mechanical properties were also investigated. At the optimal conditions, bending strength of PDLLA and PDLLA/MDI is 35.1 MPa and 51.3 MPa, respectively, and their bending modulus is 2413.6 MPa and 1830.9 MPa, respectively. Bending strength of PDLLA/HA and PDLLA/HA/MDI is 31.2 MPa and 55.4 MPa, respectively, and their bending modulus is 1735.0 MPa and 2068.5 MPa, respectively. These results have shown that the mechanical properties of PDLLA/MDI and PDLLA/HA/MDI have enhanced significantly by MDI chain-extending.