Preparation and Characterization of Surface-Modified β-Tricalcium Phosphate/Ploy(L-Lactide) Biocomposites
A new surface modification method by modifying low molecular weight ploy (L-lactide) (LMW PLLA) onto the β-tricalcium phosphate (β-TCP) superfine particles has been developed. The surface-modified β-TCP is characterized by FT-IR, XRD, digital microscope and contact angle measurement, et al. FT-IR spectra confirmed that LMW PLLA was connected onto the β-TCP surface through ionic interaction. XRD results indicated that the LMW PLLA did not affect the crystalline form of β-TCP, but the XRD patterns of the p-β-TCP showed a little difference with β-TCP. The p-β-TCP particles could be dispersed uniformly in dichloromethane. In contrast, unmodified β-TCP particles are apt to agglomerate after dispersed into dichloromethane. Wet angle measurement showed that hydrolyzed LMW PLLA significantly improves hydrophobicity of modified β-TCP particles. For the preparation of composites, PLLA was mixed with β-TCP and p-β-TCP, respectively, in a ratio of 85/15 (w/w) and moulded into tensile test specimens. Tensile tests showed that mechanical properties were improved, scanning electron microscopy (SEM) exhibited that modified β-TCP is an effective approach to prepare a homogeneous composites, moreover, it indicated a better interfacial phase interaction in the composite with the p-β-TCP. Chemical bonds between filler and PLLA matrix are assumed to be formed by ionic interaction.
Huaiying Zhou, Tianlong Gu, Daoguo Yang, Zhengyi Jiang, Jianmin Zeng
J. Zou et al., "Preparation and Characterization of Surface-Modified β-Tricalcium Phosphate/Ploy(L-Lactide) Biocomposites", Advanced Materials Research, Vols. 197-198, pp. 120-126, 2011