Novel green biodegradable polylactide based polyurethane triblock copolymers reinforced with cellulose nanowhiskers
thesisposted on 24.05.2021, 14:30 by Noha Ali Abdel Hady
Novel green classes of biodegradable polylactide-based triblock polyurethane (TBPU) polymers were synthesized. Owing to their tailored mechanical properties, improved degradation rates, and the enhance cell attachment potential compared with polylactide-homopolymer, they tested for biomedical applications. Triblock copolymers (TB) of different lactide and polyethylene glycol composition were first fabricated by ring-opening polymerization using tin octoate as catalyst. Afterwich polycaprolactone diole (PCL-diole) is reacted with TB copolymers using 1,4-butane diisocyanate (BDI) as nontoxic chain extender to form the final TBPUs. Final composition, molecular weight, thermal properties, hydrophilicity and biodegradation of the obtained TB and TBPU were studied and characterized using 1H-NMR, GPC, FTIR, DSC, SEM and contact angle measurements. Results obtained from the high molecular weight members of TBPUs showed improved hydrophilicity and degradation rates along with tailored mechanical properties. Nanocomposites obtained by reinforcing TBPU3 with 7% (w/w) BCNW showed ~16% increase in tensile strength and 330% in % elongation compared with PL-homopolymer. Those polymers and their nanocomposites demonstrated promising potential to be used as bone cement, and in regenerative medicin.