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Poly(trimethylene terephthalate) (PTT) composites filled with well‐dispersed functionalized multi‐walled carbon nanotubes (MWCNT‐COOH) and graphene nanosheets (GNS) were prepared through in situ polymerization. The effect of increased nanotubes and nanosheets concentration on the electrical conductivity and rheological behavior was investigated. The electrical conductivity increased by about ten orders of magnitude for PTT/MWCNT‐COOH/GNS composites with 0.4 wt% of MWCNT‐COOH and 0.3 wt% of GNS content. For insulating hybrid polymer nanocomposites, with a MWCNT‐COOH content ≤ 0.2 wt%, GNS produces a synergic effect by acting as junction additive for MWCNT leading to additional conductive pathways. However, for hybrid nanocomposites with 0.4 wt% of MWCNT‐COOH further addition of GNS caused only slight improvement in electrical conductivity. Additionally, rheological analysis confirmed interconnected or network‐like structures formed as a result of nanofiller‐nanofiller and nanofiller‐polymer interactions. POLYM. COMPOS., 39:2961–2968, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Poly(trimethylene 2,5-furanoate) (PTF) nanocomposites reinforced with few layer graphene (FLG) were prepared through in situ polymerization. The method in question allows obtaining well-dispersed nanoplatelets in the whole volume of PTF matrix. The mechanical properties of the PTF/FLG nanocomposites slightly increased with as quantity of FLG as small as 0.1 wt%, which was best seen in the improvement of elongation at break by about two times. The presence of FLG did not affect the crystallization and chain mobility of PTF matrix. However, the incorporation of a small quantity of FLG slightly improved the thermal stability of the nanocomposites. Additionally, the cold and hot water absorption and oxygen permittivity measurements confirmed that FLG affected the tortuosity of the diffusive path for the penetrant molecule. Moreover, along with a successive addition of FLG a linear increase in thermal conductivity was visible. [ABSTRACT FROM AUTHOR]

ABSTRACT Single-walled carbon nanotubes (SWCNT)/expanded graphite (EG)/poly(trimethylene terephthalate) (PTT) hybrid nanocomposites were prepared via in situ polymerization. Raman spectroscopy and scanning electron microscopy (SEM) were employed to determine both, purity and morphology of the nanofillers and the dispersion of nanotubes and nanosheets. The electrical and optical properties of thin polymer films based on both 'single' nanocomposites and hybrid nanocomposites were studied. For PTT/SWCNT nanocomposites, results confirmed that films optical transmittance decreases as the concentration of SWCNT increases, attaining almost no optical transmittance for 0.3 wt % of nanofiller. Conversely, the electrical conductivity of nanocomposites was found to increase by increasing the nanofiller amount and the σdc values indicate that percolation occurs at a very low SWCNT content (around 0.05 wt %). In the case of PTT/SWCNT + EG nanocomposites, when the content of SWCNT is 0.05%, the hybrid system presents lower conductivity than that corresponding to the 'single' nanocomposite. The incorporation of additional EG to the PTT/SWCNT nanocomposite has a small effect on the electrical conductivity but inhibits the transparency of the system. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44370. [ABSTRACT FROM AUTHOR]

Graphene nanoplatelets/single walled carbon nanotubes/poly(trimethylene terephthalate-block-poly(tetramethylene oxide) segmented copolymer (GNP/SWCNT/PTT-PTMO) hybrid nanocomposites were synthesized via in situ polymerization. A remarkable synergistic effect between GNPs and SWCNTs on improving thermal and mechanical properties of nanocomposites based on segmented block copolymers was observed. Heterogeneous structure of the PTT-PTMO allowed for a better and more uniform distribution of both types of nanoparticles and stabilized the structure in question. This enabled us to observe a so-called 'synergistic effect', caused by the use of mixture of carbon nanotubes and graphene nanopletelets, on the enhancement of thermal and mechanical properties of the obtained polymer. In order to ascertain the influence of mentioned carbon nanostructures on the nano-phase-separated structure of the synthesized PTT-PTMO block copolymers, differential scanning calorimetric (DSC) and dynamic mechanical thermoanalysis (DMTA) measurements were performed. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images of the PTTPTMO nanocomposites displayed that hybrid nanofillers exhibited better distribution and compatibility than SWCNTs and GNPs did individually. The tensile modulus of 0.5SWCNT/0.1GNP/PTT-PTMO composites was 68% higher than that of the PTT-PTMO alone, compared to only a 10 and 28% increase in tensile modulus for 0.3GNP/PTT-PTMO and 0.3SWCNT/PTT-PTMO composites respectively (the highest concentration when single nanofiller was added). [ABSTRACT FROM AUTHOR]

Nanocomposites based on poly(ethylene terephthalate) (PET) and expanded graphite (EG) have been prepared by in situ polymerization. Morphology of the nanocomposites has been examined by electronic microscopy. The relationship between the preparation method, morphology, and electrical conductivity was studied. Electronic microscopy images reveal that the nanocomposites exhibit well dispersed graphene platelets. The incorporation of EG to the PET results in a sharp insulator-to-conductor transition with a percolation threshold (ϕc) as low as 0.05 wt %. An electrical conductivity of 10−3 S/cm was achieved for 0.4 wt % of EG. The low percolation threshold and relatively high electrical conductivity are attributed to the high aspect ratio, large surface area, and uniform dispersion of the EG sheets in PET matrix. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 [ABSTRACT FROM AUTHOR]