Coating of bioactive glass particles with mussel-inspired polydopamine as a strategy to improve the thermal stability of poly(l-lactide)/bioactive glass composites

Abstract

Fabrication of bioactive glass (BG) filled polyester composites by traditional thermoplastic processing techniques is limited because a thermal degradation reaction occurs between the Si–O⁻ groups present on the surface of the BG and the CO groups present in the backbone of the polymer at high temperatures. To overcome this problem, this study looked at the effect of mussel-inspired polydopamine (PDA) coated on the surface of BG particles. Thermogravimetric analysis demonstrated the improved thermal stability of poly(L-lactide) (PLLA) composites filled with PDA-coated BG particles compared to PLLA composites filled with uncoated BG particles. Moreover, these composites were successfully manufactured by hot-pressing, showing enhanced mechanical properties in comparison to non-coated BG filled PLLA composites. Dynamic mechanical analysis indicated a good interfacial interaction between PDA-coated BG particles and the PLLA matrix, suggesting that an immobilized layer of polymer chains was formed around the BG particles. Finally, the bioactivity of PLLA samples filled with 15 vol% of PDA-coated BG particles was confirmed via the deposition of an apatite layer on the surface of the material. In view of the results obtained it can be concluded that coating BG particles with PDA is a promising strategy as it can create composite materials with improved thermal stability and bioactivity.