International Journal of Research in Engineering and Applied Sciences(IJREAS) Available online at http://euroasiapub.org/journals.php Vol. 7 Issue 6 , June-2017, pp. 129~141 ISSN (O): 2249-3905, ISSN(P): 2349-6525 | Impact Factor: 7.196 International Journal of Research in Engineering & Applied Sciences Email:- editorijrim@gmail.com, http://www.euroasiapub.org An open access scholarly, online, peer-reviewed, interdisciplinary, monthly, and fully refereed journal 129 Studies on Mechanical Properties of Calcium Carbonate Filled PPO Composite with Coupling Agent Dr. R.S.N.Sahai 1 , Sunil Patel 2 , Sunny Santwani 3 , Roshan Jaiswal 4 RSN Sahai Department General Engineering, Institute of Chemical Technology, Mumbai. MH 400019. India. ABSTRACT Polyphenylene oxide (PPO) is an engineering polymer with high good dimension stability and widely used in the automotive and electrical industry. Calcium carbonate (CaCO 3 ) is one of the most popular mineral fillers used in the polymer composite. It is widely available around the world, easy to grind or reduce to a specific particle size, compatible with a wide range of polymer resins and economical. In the present research work calcium carbonate filled PPO composite of different concentration loading of filler which is 5% to 25%, were prepared by using untreated and surface treated of calcium carbonate with silane coupling agent. Calcium carbonate filled PPO composite with silane coupling agent and without coupling agent was compounded in twin screw counter rotating, having L/D ratio 25:1 and 16mm diameter Extruder, for various compositions and test samples were prepared from the compression moulded sheet. These samples were tested for mechanical properties. The result shows decrease in the Melt flow index, impact strength and elongation at break. There is increase in Flexural modulus with filler loading. There is increase in Tensile strength and Flexural strength, initially with filler loading, followed by decrease in it at higher loading. The improvement in the mechanical properties are seen when calcium carbonate is treated with 3- aminopropyl triethoxy silane as compared to untreated calcium carbonate filled PPO composite. Key words- PPO, Calcium carbonate, silane coupling agent . Introductions W.C.J. Zuiderduin et al. [1] S t u d i e d Toughening of polypropylene with calcium carbonate particles. Polypropylene–CaCO3 composites were prepared on a twin screw extruder with a particle content of 0– 32 vol%. The influence of particle size (0.07–ͳ.9 μmȌ and surface treatment of the particles ȋwith and without stearic acid) on the toughening properties were studied. The matrix molecular weight of the polypropylene was also varied (MFI 0.3–24 dg/min). The modulus of the composites increased, while the yield stress was lowered with filler content. This lowering of yield stress was connected to the debonding of the particles from the polypropylene matrix. From DSC experiments it was shown that the particle content had no influence on the melting temperature or crystallinity of the PP phase, also particle size showed no effect on the thermal properties. The impact resistance showed large improvement with particle content. The stearic acid coating on the particle surface showed a large positive effect on the impact strength. Nhol Kao et al. [2] investigated that the extensional rheology (through melt strength measurement) of calcium carbonate (CaCO 3 ) filled polypropylene (PP) melts. Different concentrations of CaCO 3 filled PP were produced by mixing two master batches of pure PP and 70wt% CaCO 3 filled PP in required proportions in a counter-rotating twin-screw extruder. It has reported that the melt strength of