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Creep, recovery, and stress relaxation behavior of nanostructured bioactive calcium phosphate glass–POSS/polymer composites for bone implants studied under simulated physiological conditions
Author(s) -
Belyamani Imane,
Kim Kyoungtae,
Rahimi Shahab Kashani,
Sahukhal Gyan S.,
Elasri Mohamed O.,
Otaigbe Joshua U.
Publication year - 2019
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.34335
Subject(s) - materials science , creep , composite material , stress relaxation , viscoelasticity , relaxation (psychology) , polymer , apatite , modulus , elastic modulus , chemical engineering , psychology , social psychology , engineering
The creep and recovery and the stress relaxation behaviors of poly(butylene adipate‐co‐terephthalate) (PBAT) and polyhydroxyalkanoates (PHA) binary blends incorporating 30 wt % of a mixture of trisilanolisobutyl polyhedral oligomeric silsesquioxanes (POSS) and calcium phosphate glass (CaP‐g) were investigated under simulated physiological and human body temperature conditions. The synergistic effect of PHA and CaP‐g/POSS filler remarkably improved the creep behavior of the PBAT matrix and decreased its residual strain, consequently enhancing its elastic recovery. A considerable increase of the relaxation modulus of the hybrid materials was also observed upon incorporation of PHA and CaP‐g/POSS. The relaxation modulus of the neat PBAT sample increased from ~60 MPa to ~1600 MPa after addition of 30 wt % CaP‐g/POSS and 70 wt % PHA. However, after exposure of the composites to the simulated human body conditions for 14 days, a drop of dynamic mechanical properties of the studied material systems was observed along with formation of a desirable calcium phosphate phase on the material surface. The long‐term (i.e., up to 7 × 10 5 s) viscoelastic behavior of the studied materials was successfully predicted using the time–temperature superposition principle and the obtained creep strain and the relaxation modulus master curves were satisfactorily fitted to the Findley power law equation and the generalized Maxwell model, respectively. This study demonstrates a facile method for tailoring CaP‐g/POSS bioactive glasses composition for bone‐like apatite formation on biopolymer surfaces. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2419–2432, 2019.