Synthesis and micromechanical properties of graphene oxide-based polymer nanocomposites

Abstract

The authors have studied the effect of small (≤ 1 wt%) additions of thermally reduced graphene oxide on the microhardness and microindentation kinetics in two types of polymers: polystyrene (i.e. thermoplastic with a glass transition temperature of Tg ≈ 373 K) and polyester resin (i.e. thermosetting plastic, Tg ≈ 300 K). The room temperature creep of nanocomposites under an indenter is described using a three-element rheological Kelvin–Voigt model. The study determines the parameters of this model and how graphene oxide (GO) affects them. In a polystyrene nanocomposite with 0.3 wt % graphene oxide, unrelaxed and relaxed elastic moduli, and the modulus characterizing high-elastic deformation, increase by 11%, 40% and 87%, respectively, as compared to the initial polystyrene; at the same time, microhardness increases by 38% and 45% for the different series of samples. The results obtained indicate that the presence of graphene oxide in the nanocomposite severely restricts the mobility of molecular segments. The addition of 0.3 wt% graphene oxide to polyester resin is accompanied by an increase in the mechanical glass transition temperature of the resin by at least 5 K. This leads to a change in the relaxation state of this polymer: while at room temperature the polyester resin behaves like an elastomer, a polyester resin nanocomposite with 0.3 wt% graphene oxide exhibits glassy properties. At room temperature, the microhardness of polyester resin-glass fabric-graphene oxide nanocomposites with a GO content of 0.5 and 1 wt% increases by 20% and 80% respectively, as compared to that of a polyester resin-glass fabric composite. The authors have obtained the temperature dependences of the microhardness of nanocomposites with a polyester matrix in the range 77–298 K, and have also identified temperature regions where the microdeformation of composites is reversible, which is associated with the formation of crazes with a lower glass transition temperature.

Recent Advances in the Development of Lipid-, Metal-, Carbon-, and Polymer-Based Nanomaterials for Antibacterial Applications

“…With this method, facile synthesis is achieved by simply blending the polymer with GO in solution, followed by sonication, or magnetic stirring, or shear mixing to obtain homogenous dispersions of the nanocomposite products as depicted in Figure 10 [ 340 , 341 ]. In Rusakova et al’s study, an ultrasonic bath was used to disperse GO in a solution of styrene or a polyester resin in styrene, adding toluene and benzoyl peroxide and then, the mixture was placed into a special mold for polymerizing the nanocomposite [ 342 ].…”

The impact of temperature on electrical properties of polymer-based nanocomposites

“…Such hybrid materials are of great practical interest because of their improved thermal conductivity, radiation resistance, electrical insulation of thermoplastics, and thermal performance [5][6][7][8][9]. Obtained hybrid nanocomposites based on organic semiconductors, ferroelectric and magnetic materials are used in light emitting devices, lighting holders, various electronic devices, motors and battery casing, temperature sensors and optimized heat exchangers [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24].…”