Surface modified graphene/single-phase polyurethane elastomers with improved thermo-mechanical and dielectric properties. (September 2015)

• Record Type: Journal Article
• Authors: Ljubic, Darko; Srinivasan, Madhusudhan; Szoszkiewicz, Robert; Javni, Ivan; Petrović, Zoran S.
• Is Part Of: European polymer journal. Volume 70(2015)
• Page Start: 55
• Page End: 65
• Publication Date: 2015-09
• Subjects: Graphene -- Surface modification -- Polyurethane elastomer -- Nanocomposites -- Properties; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2015.07.008
• Languages: English
• ISSNs: 0014-3057

Abstract

Abstract : Graphical abstract: Highlights: Efficient, simple and fast method for graphene surface modification is reported. Soft single-phase polyurethane/surface modified graphene elastomers are produced. Surface modified graphene improve thermo-mechanical properties of polyurethane. High permittivity of nanocomposites suggest enhanced dielectric properties of PU. Abstract: We report an efficient, simple and fast method for graphene surface modification and its novel use for the fabrication of very soft, single-phase polyurethane (PU) nanocomposite elastomers. Content of the surface modified graphene (SMG) in PU was between 0.2 and 5 wt%. FT-IR and thermogravimetric analysis indicated successful surface modification of graphene by 3-aminopropyltriethoxysilane while a large increase in the viscosity of the polyol blend with SMG content suggested its exfoliation down to six graphene layers, as observed by atomic force microscopy (AFM). The scanning electron microscopy and AFM of elastomers revealed strong SMG–PU interactions and good dispersion of SMG within the matrix, respectively. Consequently, we measured more than a two-fold increase in the tensile strength and storage modulus of SMG/PU elastomer at addition of 5 wt% of SMG, compared with unfilled PU. An initial degradation temperature and the maximum rate of weight loss of PU with 5 wt% SMG was upshifted by 10 °C and 8 °C, respectively, showing improved thermal stability of the matrix. Finally, an increased dielectric permittivity at 1 Hz from 3.6 for unfilled PU up to 34.2 for PU elastomer with 5 wt% SMG, in the glassy state, was observed by dielectric spectroscopy indicating energy storage capabilities of these nanocomposites.