Materials and Design 88 (2015) 950–957 Enhancing the thermal, electrical, and mechanical properties of silicone rubber by addition of graphene nanoplatelets Yingze Song a , Jinhong Yu a, ⁎, Lianghao Yu a , Fakhr E. Alam a , Wen Dai a , Chaoyang Li b , Nan Jiang a, ⁎ a Key Laboratory of Marine Materials and Related Technologies, Zhejiang Key Laboratory of Marine Materials and Protective Technologies, Ningbo Institute of Materials Technology & Engineering, Chinese Academy of Sciences, Ningbo 315201, China b Research Institute & School of Systems Engineering, Kochi University of Technology, Kami, Kochi 782-8502, Japan a r t i c l e i n f o Article history: Received 26 July 2021 Received in revised form 29 july 2021 Accepted 02 August 2021 Available online 07 August 2021 Keywords: Composites Graphene nanoplatelets Thermal conductivity Electrical properties Mechanical properties a b s t r a c t Graphene nanoplatelets (GNPs)/silicone rubber composites were prepared with the assistance of the Flacktek SpeedMixer. A scanning electron microscope (SEM), transmission electron microscopy (TEM), Raman spectra, Fourier-transform infrared spectra (FTIR), and X-ray photoelectron spectra (XPS) were carried out to character- ize the structure of graphene nanoplatelets. An electronic universal testing machine, laser thermal conductivity analysis (LFA), thermogravimetric analysis (TGA), and a scanning electron microscope (SEM) reveal the effects of GNP loading content on the thermal conductivity, electrical, and mechanical properties of the composites. The results show that the GNPs present a homogeneous dispersion in silicone rubber and the thermal conductiv- ity of composites exhibits improving from 0.16 to 0.26 W / (m · K) (an increase of 53.1%) and the tensile strength varies from 0.240 to 0.608 MPa (an increase of 153%) with the addition of a low content (0–8%) of GNPs. In addition, the thermal stability of silicone rubber composites is signi ficantly enhanced. © 2015 Elsevier Ltd. All rights reserved. 1. Introduction Silicone rubber due to its properties like high resistance of heat and electric insulation can be used in various fields, such as electronic devices and gate dielectrics. Some disadvantages of pure silicone rubber can be overcome by adding fillers [1,2]. GNPs have attracted tremen- dous attention due to its unique thermal, electrical, and mechanical properties [3,4], which have very high thermal conductivity with 2-D structure for phonon transport and offer an interface contact area with polymer matrix resulting in the improvement of the various properties of the composite. GNPs are used as filler in epoxy resin [5,6], natural rubber [7,8] and other polymer matrix [9,10] to enhance their thermal, electrical, and mechanical properties. GNPs are the promising candidate material for the application in thermal management. However, there are two factors which limit the application of GNPs as filler in polymer matrix: (i) coagulated network generated by platelet–platelet aggregation and (ii) structural network, constructed by the interfacial adhesion due to the platelet–polymer interactions. The two factors have strong effect on the properties of composites [11]. In order to improve the properties of GNP-polymer composite, the surface of GNPs is modified either physically or chemically [12,13]. For instance, S. K Yadav et al. [14] modified the surface of GNPs by using 4-aminophenethyl alcohol and found that modified GNPs had positive effect on the resulting composite while enhancing their ⁎ Corresponding authors. E-mail addresses: yujinhong@nimte.ac.cn (J. Yu), jiangnan@nimte.ac.cn (N. Jiang). mechanical, thermal, and shape recovery properties. B. Li et al. [15] proposed that GNPs modified with organosilane exhibited an improved dispersal property and provided strong interfacial bonding with polyetherimide matrix. It is generally considered that the surface modification of GNPs is beneficial to improve the dispersal property of GNPs in polymer matrix. However, the modifying process is usually complicated and contains many approaches. In this paper, the Flacktek SpeedMixer was used to disperse the GNPs in MVQ. This blender works by the spinning of a high speed mixing arm at speeds up to 3000 rpm in one direction while the basket rotates in the opposite direction. As a result, this blender could offer an excellent blend method with combination of forces in different planes by rapid mixing. The objective of this paper is to fabricate GNP-silicone rubber composites and investigate the effects of GNP loading content on thermal, electrical and mechanical properties of the composites. 2. Experimental details Materials Silicone rubber (methyl-vinyl-silicone, MVQ 110-2) was purchased from Dongjue Silicone Group Co., Limited, China. It has average molecu- lar weight Mw = 6.5 × 10 5 , and contains 0.17 mol% vinyl groups on backbone chain. Commercial graphene nanoplatelets (GNPs) were pro- vided by Ningbo Institute of Materials Technology and Engineering, China and the GNPs have a flaky sheet structure in shape with width of less than 12 μm and thickness of about 3 nm. Benzoyl peroxide http://dx.doi.org/10.1016/j.matdes.2015.09.064 0264-1275/© 2015 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Materials and Design journal homepage: www. elsevier.com/locate/jmad