1 ISSN 0965-545X, Polymer Science, Series A © Pleiades Publishing, Ltd., 2017. Enhanced Dielectric Properties of Polyethylene Glycol (PEG) Modified BaTiO 3 (BT)-Poly(vinylidene fluoride) (PVDF) Composites 1 Srikanta Moharana a , Mukesh K. Mishra a , Banarji Behera b , and R. N. Mahaling a, * a Laboratory of Polymeric and Materials Chemistry, School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768019 India b Materials Research Laboratory, School of Physics, Sambalpur University, Jyoti Vihar, Burla, Odisha, 768019 India *e-mail: rnmahaling@suniv.ac.in Received June 23, 2016; Revised Manuscript Received December 7, 2016 Abstract—To improve the compatibility between the ceramic particle and polymer matrix, the surface mod- ifier polyethylene glycol (PEG) was used for the modification of BaTiO 3 (BT) particles as fillers in the poly(vinylidene fluoride) (PVDF) matrix via solution casting techniques. The structural analysis of the com- posite characterized by X-ray diffraction confirms the tetragonal structure. The results showed that the PEG modified BT-PVDF composites had a higher dielectric constant (≈192) and relatively lower dielectric loss value at 1000 Hz. The Nyquist plot suggests the contribution of only bulk effect present in the composites. The AC electrical conductivity studies obey Jonscher’s universal power law by fitting AC conductivity data which reveals the potential utility of the composites for ideal capacitor and microscopic reasons for this improvement were presented. Furthermore, the remnant polarization was significantly improved and maxi- mum polarization was observed for PEG modified BT-PVDF composites. DOI: 10.1134/S0965545X17030130 INTRODUCTION In recent years, studies on dielectric polymer com- posites with high dielectric constant have been paying much attention from academic research and industry because polymers are flexible and they have low-cost and good process-ability [1, 2]. While the combina- tion of ferroelectric ceramic and a polymer matrix to form composite can lead to various aspects, they are still to be challenged for the development of novel materials that have better dielectric and mechanical properties [3, 4]. Barium titanate (BaTiO 3 ; BT) is a typical per- ovskite-type ceramic material and is used broadly because of its high dielectric constant and unique piezoelectric, pyroelectric, thermo-electric and ferro- electric properties [5]. It is widely used in the micro- electronics including gate dielectrics actuators, infra- red detectors, tunable capacitors, electro optic devices and sensors [6, 7]. To date, many attempts have been made to improve dielectric properties of the polymer- BT composites, mainly those with large amounts of BT loading (30–90 vol %) [8–10]. So the key chal- lenge to get high energy density to enhance the dielec- tric constant and breakdown strength of the dielectric materials. The polymers such as poly(vinylidene fluo- ride) (PVDF) is a semi-crystalline material is gener- ally used as an insulating matrix because of its good chemical resistance, dielectric constant, easy process- ing and low cost [11]. However, the crucial effect of dielectric properties of the ceramic particles are that, they agglomerated into the polymer matrix. To reduce the agglomeration of such ceramic based polymer composites, various researchers have tried to modify the ceramics with the help of surface treating agents, which are used for homogeneous dispersion of fillers into the polymer matrix [8, 12, 13]. Thus, it becomes a useful route to develop the surface modification of ceramic fillers to modify the interface areas between the ceramic particles and the polymer matrix and improve the homogeneity of the composites. Further, there is not only consideration for dispersion of ceramic fillers, but also important for the compatibil- ity of the polymer matrix. Thus it is necessary to choose the appropriate surface modifying agent for the preparation of ceramic based polymer composites with better dielectric and electrical properties. Recently, PEG has been used to modify the surface of ceramic particles in order to improve the dielectric properties of composites. There are few studies based 1 The article is published in the original. COMPOSITES