Strength of Materials, Vol. 51, No. 5, September, 2019 DEVELOPMENT OF GRAPHENE NANOPLATELETS-REINFORCED THERMO-RESPONSIVE SHAPE MEMORY NANOCOMPOSITES FOR HIGH RECOVERY FORCE APPLICATIONS R. Kumar Gupta, a,1 S. A. R. Hashmi, a,b S. Verma, a,b UDC 539.4 and A. Naik b The development and large-scale implementation of multifunctional advanced materials with smart and intelligent properties like shape memory are very topical. In the present work, we report the development of multifunctional graphene nanoplatelets (GNPs)-reinforced thermo-responsive shape memory composites, in ether type shape memory polyurethane (SMPU) matrix. A unique twin screw co-rotating microcompounder with a back flow channel was operated to ensure proper dispersion of GNPs in the SMPU matrix for developing different compositions of nanocomposites, namely SMC0, SMC1, SMC2, and SMC3, respectively. The detailed characterizations and properties of the above developed nanocomposites were studied using various complementary techniques for spectroscopy, morphology, mechanical, thermal, shape memory, DMA, etc. The dynamic thermomechanical properties of all the developed nanocomposites were studied at 0.1 and 10 Hz, respectively. Structure of SMP and developed composite were also analyzed using various spectroscopic methods. The addition of GNPs to the SMP matrix improved the mechanical and shape memory properties, although a noticeable impact on thermal property is also reported. The fractured microphotographs reveal the uniform dispersion of GNP in SMPU. Addition of 1 phr GNPs increased storage modulus of SMPU from 3.14 to 4.11 GPa and the value of tan d peak was decreased from 0.81 to 0.53, respectively. The GNPs in SMPU matrix influences the shape recovery, which is improved with the addition of GNPs in the experimental range. Keywords: shape memory polymer, shape memory polyurethane, graphene nanoplatelets, dynamic mechanical analysis, microcompounder. Introduction. With the scientific and technological interventions, the development of smart and multifunctional materials became the global hotspot. Among various other smart materials, shape memory polymers (SMPs) play a critical role due to their superior qualities like ability to undergo a large recoverable deformation [1] upon the application of external stimuli such as heat [2, 3], light [4, 5], moisture [6], electric current [7, 8], magnetic field [9], and pH [10]. These SMPs have broad and high potential applications in the area of biomedical, actuator, sensor, smart textile, self-deployable structure, and artificial muscles [11, 12], etc. Although SMPs have few drawbacks (like low recovery force [13], low thermal and electrical conductivity), they possess several advantages over other shape memory alloys like exceptional high recovery strain, easy processability, low cost, and easy shape memory programming. In thermo-responsive polymer, temperature acts as a transition switch thereby changing shape from temporary to permanent one. SMPs change their stiffness from glassy state (high stiffness) to rubbery state (low stiffness) above glass transition temperature. Among other SMPs, the thermoplastic shape memory polyurethanes 0039–2316/19/5105–0793 © 2019 Springer Science+Business Media, LLC 793 a Academy of Scientific and Innovative Research (AcSIR), AMPRI, Bhopal, India ( 1 ritesh.ampri@gmail.com). b Council of Scientific and Industrial Research – Advanced Materials and Processes Research Institute (AMPRI), Bhopal, India. Translated from Problemy Prochnosti, No. 5, pp. 130 – 143, September – October, 2019. Original article submitted October 23, 2018. DOI 10.1007/s11223-019-00130-4