Mater. Lett.

The biodegradable nanocomposite of poly(methacrylated pyromellitylimidoalanine) (PM(PMA-ala)) and hydroxyapatite (HAp) was prepared by dispersing nanosized needle-like HAp particles prepared by homogeneous precipitation under hydrothermal condition into the crosslinked PM(PMA-ala) network via in-situ photo-polymerization. The conversion of carbon carbon double bonds of multifunctional anhydride monomers after the heat treatment can be over 90%, and the HAp needles are distributed homogeneously in the PM(PMA-ala) crosslinking network. By increasing the content of HAp, the mechanical properties of HAp/PM(PMA-ala) nanocomposite is improved two to three times those of PM(PMA-ala) itself. Furthermore, in contrast with PM(PMA-ala), the nanocomposite HAp/PM(PMA-ala) has higher modulus retention and lower mass loss at the same degradation time, and this tendency will be enhanced as the increase of the content of HAp. (C) 2003 Published by Elsevier Science B.V.The biodegradable nanocomposite of poly(methacrylated pyromellitylimidoalanine) (PM(PMA-ala)) and hydroxyapatite (HAp) was prepared by dispersing nanosized needle-like HAp particles prepared by homogeneous precipitation under hydrothermal condition into the crosslinked PM(PMA-ala) network via in-situ photo-polymerization. The conversion of carbon carbon double bonds of multifunctional anhydride monomers after the heat treatment can be over 90%, and the HAp needles are distributed homogeneously in the PM(PMA-ala) crosslinking network. By increasing the content of HAp, the mechanical properties of HAp/PM(PMA-ala) nanocomposite is improved two to three times those of PM(PMA-ala) itself. Furthermore, in contrast with PM(PMA-ala), the nanocomposite HAp/PM(PMA-ala) has higher modulus retention and lower mass loss at the same degradation time, and this tendency will be enhanced as the increase of the content of HAp. (C) 2003 Published by Elsevier Science B.V