Sains Malaysiana 42(4)(2013): 495–501

Effect of Compatibilizer on the Dynamic Mechanical and Electrical Properties of Kaolin

Clay Reinforced EPDM Rubber

(Kesan Pengserasi Terhadap Sifat Mekanik dan Elektrik Dinamik Kaolin Bertetulang Getah EPDM)

Gautam Sarkhel* & Sanjay Manjhi

Department of Polymer Engineering, Birla Institute of Technology, Mesra-835215,

Ranchi, Jharkhand, India

Received: 19 June 2011 / Accepted: 3 April 2012

ABSTRACT

Industrial pollution issue and dark colour of carbon black, clay based non black filler are getting more importance for reinforcing elastomer. EPDM-Kaolin composites with various maleated EPDM concentration have been prepared by mixing on a two roll mill. The rheometry data showed the optimum cure time increases with increasing compatibilizer concentration without decreasing torque value indicating that acidic functional groups comes from compatibilizer could retard cure rate and increase the optimum cure time rather than change in the ultimate cure state. As the filler concentration increases, the edge to edge and face to edge interaction between filler and EPDM increases and the free volume between EPDM molecules is reduced, the storage modulus increases. Moreover, the dynamic mechanical analysis also showed the increase in glass transition temperature with increase in filler concentration due to the inter-tubular diffusion of EPDM inside the clay. It was also observed that with increasing filler concentration, the resistivity and dielectric strength decreases and moreover with increasing compatibilizer concentration the resistivity decreases due to better dispersion of filler helps to build conduction path. The morphological study also revealed that homogeneity of filler dispersion increases with increase in compatibilizer concentration.

Keywords: Dielectric constant; dielectric strength; EPDM; kaolin; resistivity

ABSTRAK

Isu pencemaran perindustrian dan warna gelap karbon hitam, tanah liat berasaskan pengisi bukan hitam semakin lebih penting untuk mengukuhkan elastomer. EPDM-Kaolin komposit dengan pelbagai kepekatan EPDM telah disediakan dengan mencampurkan dalam pengisar dua rol.  Data menunjukkan peningkatan masa awet optimum dengan kepekatan pengserasi tanpa mengurangkan nilai tork yang menunjukkan bahawa asid kumpulan berfungsi daripada pengserasi boleh membantut kadar awetan dan meningkatkan masa penyembuhan optimum merubah keadaan penyembuhan. Apabila kepekatan pengisi meningkatkan interaksi tepi ke tepi dan antara muka pengisi dan EPDM bertambah dan isi padu bebas antara molekul EPDM dikurangkan dan penyimpanan modulus bertambah. Selain itu analisis mekanik dinamik juga menunjukkan peningkatan dalam suhu peralihan kaca dengan peningkatan kepekatan pengisi disebabkan resapan antara tiub EPDM di dalam tanah liat. Dengan peningkatan kepekatan pengisi, kerintangan dan kekuatan dielektrik berkurangan dengan kepekatan pengserasi yang meningkat, kerintangan berkurangan disebabkan penyebaran pengisi yang lebih baik membantu untuk membina rangkaian pengaliran. Kajian morfologi juga mendedahkan bahawa kehomogenan penyebaran pengisi meningkat dengan peningkatan dalam kepekatan pengserasi.

Kata kunci: EPDM; kaolin; kekuatan dielektrik; kerintangan; pemalar dielektrik

REFERENCES

Arroyo, M., Lopez-Manchado, M.A. & Herrero, B. 2003. Organo-montmorillonite as substitute of carbon black in natural rubber compounds. Polymer 44(8): 2447-2453.

Ghosh, P. & Chakraborty, A. 2000. Conducting carbon black filled EPDM vulcanizates: assessment of dependence of physical and mechanical properties and conducting character on variation of filler loading. European Polymer Journal 36: 1043-1054.

Ismail, H. & Chia, H.H. 1998. The effects of multifunctional additive and epoxidation in silica filled natural rubber compounds. Polym. Test. 17(3): 199-210.

Manjhi, S. & Sarkhel, G. 2010. Effect of maleic anhydride grafted ethylene propylene diene monomer (MAH-g-EPDM) on the properties of kaolin reinforced EPDM rubber. J. of Applied Polymer Sc. 49(10): 1049-1054.

Ray, S.S. & Okamoto, M. 2003. Polymer/layered silicate nanocomposites: Areview from preparation to processing. Prog. Polym. Sci. 28(11): 1539-1641.

Usuki, A. Tukigase, A. & Kato, M. 2002. Preparation and properties of EPDM–clay hybrids, Polymer 43(8): 2185-2189.

Zonghuan, Li., Zhang, Jun. & Chen, S. 2009. Effect of carbon blacks with various structures on electrical properties of filled ethylene-propylene-diene rubber. J. of Electrostatics 67: 73-75.

*Corresponding author; email: gautamsarkhel@bitmesra.ac.in