FTIR spectra of (a) PLGA fibres, (b) HA nanopowder, (c) PLGA–HA composite fibres, and (d) sintered PLGA–HA fibres. The pure PLGA spectrum shows the C3O characteristic bands in the region 1065–1280 cm−1. The spectrum of HA nanopowder reveals the characteristic peak assigned to PO43−: ν1 vibration mode at about 964 cm−1, ν3 vibration mode at 1031 cm−1 and 1091 cm−1 (asymmetric) respectively. The spectrum of untreated PLGA–HA 50% displays both characteristics of PLGA and HA. However the spectrum of CaP fibres shows the loss of the characteristics of PLGA (C3O bands), suggesting the successful thermal degradation of the polymer, while the characteristics of HA (PO43−) remain present.
pure PLGA spectrum
C3O characteristic bands
1065–1280 cm−1
cm−1
spectrum of HA nanopowder
ν1 vibration mode
about 964 cm−1
cm−1
spectrum of HA nanopowder
ν3 vibration mode
1031 cm−1
cm−1
spectrum of HA nanopowder
ν3 vibration mode
1091 cm−1
cm−1
PLGA–HA
50%