Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5182497 | Polymer | 2013 | 9 Pages |
Thermally reduced graphite oxide (TrGO) was prepared by thermal exfoliation and reduction of highly oxidized graphite. The pCBT/TrGO nanocomposites were prepared by in situ ring-opening polymerization (ROP) of cyclic butylene terephthalate (CBT). The polymerization kinetics of pCBT/TrGO was monitored by dynamic time sweep in a parallel-plate rheometer. It was found that the increasing TrGO content depressed the rate and degree of CBT polymerization, which is ascribed to the reaction between the growing pCBT chains terminated with carboxyl groups and TrGO surface groups such as hydroxyl and epoxy groups at the initial polymerization stage. The grafted pCBT chains were confirmed by X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA) measurements, and the grafting content was up to 53Â wt%. Small amplitude oscillation shear (SAOS) was applied to investigate the rheological properties of pCBT/TrGO and the critical loading to form percolation network was determined as 0.47Â vol%, which confirmed the good dispersion of TrGO in matrix. The grafting reaction was also justified from nonlinear rheology and the fractal dimension analysis.
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