Study on efficiency of solid-state polycondensation on poly(ethylene terephthalate)/carbon nanotube composites
Magdalena Kwiatkowska, Inez Kowalczyk
Quarterly No. 3, 2015 pages 119-123
DOI:
keywords: carbon nanotubes, polymer composites, in situ synthesis, solid-state polycondensation
abstract One of the problems concerning carbon nanotube (CNT)/thermoplastic polyester composites, prepared by in situ synthesis, is usually a lower molecular weight of the polymer matrix when compared to a homopolymer polymerized in the same conditions. It results in lower elongation at break/mechanical strength of the polymer, which may diminish the reinforcing effect coming from polymer/CNT interactions in the composite. Extension of the reaction time brings, in turn, problems with extruding the melted composite from the reactor due to its high viscosity and in consequence material waste. The objective of this study was to evaluate the efficiency of the solid-state polycondensation process (SSP), which is commonly applied to thermoplastic polyesters on an industrial scale, as regards poly(ethylene terephthalate) (PET) filled with single-walled (SWCNT) or multi-walled (MWCNT) carbon nanotubes. The experiments were carried out using a laboratory-made vacuum SSP set-up. The presented results prove the relatively high efficiency of the process, however, the material geometry seems to be a key factor. The best results were achieved for samples with the smallest thickness. Moreover the presence of nanoparticles in the polymer does not prevent or hinder further polymerization in the solid, and the reaction effectiveness is even higher in CNT composites when compared to an unfilled polymer.