TY - JOUR
T1 - Poly(L-lactic acid)/lithium ferrite composites
T2 - Electrical properties
AU - Teixeira, S. Soreto
AU - Gama, Nuno
AU - Cordeiro, Teresa
AU - Barros-Timmons, A.
AU - Dionísio, Madalena
AU - Graça, Manuel P. F.
AU - Costa, Luís Cadillon
N1 - info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDB%2F50025%2F2020/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDP%2F50025%2F2020/PT#
Funding Information:
This work was developed within the scope of the projects i3N , UIDB/50025/2020 & UIDP/50025/2020 , and CICECO-Aveiro Institute of Materials , UIDB/50011/2020 & UIDP/50011/2020 , financed by national funds through the Portuguese Foundation for Science and Technology (FCT) / Ministry of Science, Technology and Higher Education (MCTES) .
PY - 2021/9/16
Y1 - 2021/9/16
N2 - Composites of lithium ferrite, LiFe5O8 (LFO) particles, dispersed in the biopolymer poly (L-lactic acid) (PLLA) were prepared by solvent casting in concentrations from 0 to 19.5 wt%, which were characterized by thermal analysis (TGA/DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and impedance spectroscopy (IS). As neat PLLA, all obtained composites are semi-crystalline, but the crystallinity decreasing with percentage LFO increase. Moreover, a good dispersion of LFO particles was found, with no interactions with the polymeric matrix. For the lower LFO content (3.5 wt%), dynamical relaxation processes were probed by IS, allowing to disclose subtle differences relative to the neat matrix. Above that concentration, the conductivity dominates and follows the percolation law above a quite low volume concentration of conductive particles (5.45%v/v). Therefore, depending on the LFO content different applications can be envisaged: energy storage for low concentrations and electromagnetic radiation shielding for concentrations above the percolation threshold.
AB - Composites of lithium ferrite, LiFe5O8 (LFO) particles, dispersed in the biopolymer poly (L-lactic acid) (PLLA) were prepared by solvent casting in concentrations from 0 to 19.5 wt%, which were characterized by thermal analysis (TGA/DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy and impedance spectroscopy (IS). As neat PLLA, all obtained composites are semi-crystalline, but the crystallinity decreasing with percentage LFO increase. Moreover, a good dispersion of LFO particles was found, with no interactions with the polymeric matrix. For the lower LFO content (3.5 wt%), dynamical relaxation processes were probed by IS, allowing to disclose subtle differences relative to the neat matrix. Above that concentration, the conductivity dominates and follows the percolation law above a quite low volume concentration of conductive particles (5.45%v/v). Therefore, depending on the LFO content different applications can be envisaged: energy storage for low concentrations and electromagnetic radiation shielding for concentrations above the percolation threshold.
KW - Composites
KW - Dielectric properties
KW - Dielectric relaxation
KW - Electromagnetic shielding
KW - Lithium ferrite
UR - http://www.scopus.com/inward/record.url?scp=85112745137&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2021.124100
DO - 10.1016/j.polymer.2021.124100
M3 - Article
AN - SCOPUS:85112745137
SN - 0032-3861
VL - 230
JO - Polymer
JF - Polymer
M1 - 124100
ER -