Fabrication of Poly-(DL-Lactic Acid)—Wollastonite Composite Films with Surface Modified β-CaSiO3 Particles

Abstract

Bioactive poly-(DL-lactic acid) (PDLLA)—wollastonite composite films are successfully fabricated using surface modified wollastonite (mβ-CaSiO 3) particles through solvent casting-evaporation method. The surface modification of β-CaSiO3 particles are conducted by reaction of the ceramic particles with dodecyl alcohol. Surface morphology, tensile strength, and bioactivity of the composite films are investigated. The results show that the particle distribution and tensile strength of the composite films with modified β-CaSiO3 particles are significantly improved while the bioactivity is retained. As a result, the maximum tensile strength is enhanced 52.2% when compared with the PDLLA—β-CaSiO3 composite films prepared using unmodified β-CaSiO3 particles when the inorganic filler content is 15wt%. Scanning electron microscopy (SEM) observation suggests that the modified mβ-CaSiO3 particles are homogeneously dispersed in the PDLLA matrix. The bioactivity of the composite films is evaluated by soaking in a simulated body fluid (SBF) and the result suggests that the modified composite film is still bioactive and can induce the formation of HAp on its surface after the immersion in SBF, despite the bonded dodecyl alkyl on the surface of the inorganic particles. All these results imply that the surface modification of β-CaSiO3 with dodecyl alcohol is an effective approach to prepare PDLLA—β-CaSiO 3 composite with improved properties.