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Abstract
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In this study, three polymer nanocomposites based on poly(e-caprolactone) (PCL
grafted on the graphene quantum dot (GQD), hydroxypropyl cellulose (HPC)/GQD
(GQD: HPC=1:1; w/w) and graphene oxide (GO) with 1.6wt% of ε -caprolactone (CL)
were synthesized via in-situ ring opening polymerization of CL. The synthesized
nanocomposites were characterized using FTIR, 1 H NMR, and contact angle
measurements. The lowest molecular weight for PCL/GO was obtained according to 1
H NMR spectra. Crystalline structure and thermal behavior of composites were
investigated by XRD, DSC and TGA. The results showed that the presence of HPC
and graphene-based nanofillers in nanocomposite can affect the hydrogen bonding
interaction with PCL chains, melting temperature (T m ), degree of crystallinity ( X c
(%)) and the size of crystals. According to the results, PCL/GQD-HPC had higher T m
, lower X c (%), longer PCL moieties and smaller crystals. Also, the TGA results
indicated that the nanocomposites were thermally more stable than the pure PCL.
Moreover, a conventional electrospinning process was used to prepare nanofibers of
synthesized nanocomposites blended with PCL (50:50; w/w). SEM images and
mechanical behavior study of obtained nanofibers depicted that the PCL/(PCL/GQDHPC)
nanofibers have a significant increment in the average diameter, tensile modulus
and strength in comparison with other composites.
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