Effects of types of fillers and filler loading on the properties of silicone rubber composites

Abstract

In this study, the effects of loading levels of nano BN, nano SN and synthetic ND particles on the thermal and mechanical properties of silicone rubber were investigated. Nanoparticle-filled silicone rubber composites were prepared by cast molding process. In general, incorporation of thermally conductive nanoparticles to the silicone rubber matrix improved the thermal conductivity of the composites. BN particles have the most pronounced effect on the thermal conductivity in comparison to SN and ND particles at any given loading level. TGA studies revealed that the thermal stability of the SN/silicone rubber system increased as the filler loading level increased; however, BN and ND facilitated the thermal degradation of the silicone rubber nanocomposites. For tensile test, it is observed that the addition of nanoparticles generally increased the tensile strength of silicone rubber composites compared to the neat silicone rubber. However, for BN system, the tensile strength of the composites decreased when more than 1.5 vol.% of BN is loaded in the system. The reduction was caused by the existence of voids and agglomerations in the BN/silicone rubber system. In general, tensile modulus and strain at break of nanocomposites increased with the incorporation of nanoparticles into silicone rubber matrix.

Keywords

silicone rubber nanoparticles thermal properties mechanical properties thermal interface material

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References

. DSC and DMTA studies of a thermal interface material for packaging high speed microprocessors. Thermochim Acta 2002; 392–393: 13–21.

Shaikh

Lafdi

Silvermann

. The effect of a CNT interface on the thermal resistance of contacting surfaces. Carbon 2007; 45: 695–703.

Sartre

Lallemand

. Enhancement of thermal contact conductance for electronic systems. Appl Therm Eng 2001; 21: 221–235.

Zhou

Wang

. Thermal properties of heat conductive silicone rubber filled with hybrid fillers. J Compos Mater 2008; 42(2): 173–187.

Zhou

Zhao

Liu

. Thermally conductive silicone rubber reinforced with boron nitride particle. Polym Compos 2007; 28: 23–28.

Sim

Ramanan

Ismail

Seetharamu

Goh

. Thermal characterization of Al₂O₃ and ZnO reinforced silicone rubber as thermal pads for heat dissipation purpose. Thermochim Acta 2005; 430: 155–165.

Feng

Diao

. Thermal conductivity of silicone rubber filled with ZnO. Polym Compos 2007; 28(2): 125–130.

Razeeb

Roy

. Thermal properties of single walled carbon nanotube-silicone composite. J Polym Sci Part B Polym Phys 2008; 46: 1845–1852.

Gwinn

Webb

. Performance and testing of thermal interface materials. Microelectron J 2003; 34: 215–222.

10.

Noll

. Chemistry and technology of silicones New York, NY: Academic Press, 1968.

11.

Chojnowski

. Siloxane polymers. Polymer science and technology series. Clarson

Semlyen

Englewood Cliffs, NJ: Ellis Horwood/PTR Prentice Hall, 1993, pp. 193–215.

12.

Han Z, Wood JW, Herman H, Zhang C and Stevens GC. Thermal properties of composites filled with different fillers. In: IEEE International Symposium on Electrical Insulation, ISEI 2008 (Conference Record), Vancouver, BC, 9–12 June 2008, pp. 497–501.

13.

Kemaloglu

Ozkoc

Aytac

. Properties of thermally conductive micro and nano size boron nitride reinforced silicon rubber composites. Thermochim Acta 2010; 499: 40–47.

14.

Zhou

Wang

Zhao

. A novel fiber-reinforced polyethylene composite with added silicon nitride particles for enhanced thermal conductivity. Composites: Part A 2009; 40: 830–836.

15.

Chua

Mariatti

Azizan

Rashid

. Effects of surface-functionalized multi-walled carbon nanotubes on the properties of poly(dimethyl siloxane) nanocomposites. Compos Sci Technol 2010; 70: 671–677.

16.

Chung

DDL

Mroz

. Thermally conducting aluminum nitride polymer-matrix composites. Composites: Part A 2001; 32: 1749–1757.

17.

Kochetov R, Andritsch A, Lafont U, Morshuis PHF, Picken SJ and Smit, JJ. Thermal behavior of epoxy resin filled with high thermal conductivity nanopowders. In: IEEE International Symposium on Electrical Insulation, ISEI 2009 (Conference Record), Montreal, QC, 31 May–3 June 2009, pp. 524–528.

18.

Liang Q, Xiu Y, Lin W, Moon KS and Wong CP. Epoxy/h-BN composites for thermally conductive underfill material. In: Electronic Components and Technology Conference, ECTC 2009, San Diego, CA, 26–29 May 2009, pp. 437–440.

19.

Zhou

S-H

Zhao

Liu

. Thermally conductive silicone rubber reinforced with boron nitride particle. Polym Compos 2007; 28(1): 23–28.

20.

Tavman

. Effective thermal conductivity of isotropic polymer composites. Int Commun Heat Mass Transfer 1998; 25(5): 723–732.

21.

Dey

Tripathi

. Thermal properties of silicone powder filled-high density polyethylene composites. Thermochim Acta 2010; 502: 35–42.

22.

Liufu

S-C

Xiao

H-N

Y-P

. Thermal analysis and degradation mechanism of polyacrylate/ZnO nanocomposites. Polym Degrad Stab 2005; 87: 103–110.

23.

Chan

Mariatti

Lockman

Sim

. Effect of ultrasonication medium on the properties of copper nanoparticle-filled epoxy composite for electrical conductive adhesive (ECA) application. J Mater Sci Mater Electron 2010; 21: 772–778.

24.

Farhang

Ehsani

Jazayeri

. Effects of the filler type and quantity on the flashover voltage and hydrophobicity of RTV silicone rubber coatings. Iran Polym J 2009; 18(2): 149–157.