Polyurethane/Nitrogen-Doped Graphene Quantum Dot (N-GQD) nanocomposites: synthesis, characterization, thermal, mechanical and shape memory properties

Effects of graphene quantum dot (GQD) on photoluminescence, mechanical, thermal and shape memory properties of thermoplastic polyurethane nanocomposites

“…Additionally, the observed peak at 1350/cm in N‐GQD's spectrum, attributed to C‐N groups, cannot be observed in that of GQD. The characteristic peaks in nanocomposites' spectra are similar to our previous work which verifies the successful synthesis of samples via in situ polymerization method, as well as indicates that the incorporation of GQDs has not changed the chemical structure of PU 18 …”

“…Tin (II) bis (2‐ethylhexanoate) (Sn (Oct) 2 , 96%) and citric acid were obtained from Alfa Acer (USA) and Sigma‐Aldrich, respectively. PCL ( M n = 2000 g/mol) and PU with a molar ratio of 2(PCL)/1(HDI)/1(BDO) were synthesized by the procedure described in our previous work 18 …”

“…Various PU/GQDs nanocomposites containing 1.5, 1, and 0.5 wt.% of GQD nanoparticles were synthesized via in situ polymerization approach with a molar ratio of 2(HDI)/1(BDO)/1(PCL) using the procedure described in the previous study 18 . The synthesis steps were summarized for the sample containing 0.5 wt.% of GQDs in the following.…”

“…Different works have previously been conducted about SMPU nanocomposites and tried to mainly focus on the mechanical properties and shape memory behaviors of the various SMPU nanocomposites. As it could be understood, most of the authors have reported that these properties have been decreased by the incorporation of different contents of various nanofillers 18,19 . However, our research group have recently reported that the incorporation of graphene nanosheets and PCL‐functionalized graphene nanosheets improved the SF and SR ratios; and moreover, three effective factors including HBI (C=O) , crystallinity, and filler content, control the mechanical properties of the nanocomposites.…”

“…Then, various PU/GQD nanocomposites with different GQD nanoparticles contents were prepared by in situ polymerization approach. The main objectives of this study are the investigation of the effects of GQD nanoparticles incorporation on mechanical, optical, thermal, and shape memory properties of nanocomposites and comparing them with the PU/N‐GQD nanocomposites prepared via in‐situ polymerization approach reported in our previous work 18 …”