Oil bleed from elastomeric thermal silicone conductive pads

Abstract

Oil bleed is a serious problem in elastomeric thermal silicone conductive pads. The components of the oil bleed and the effect of the silicone chemical parameters on the amount of oil bleed have been determined. The main components of oil bleeds are the uncrosslinked silicones in the cured resins, which include the unreacted silicone materials and the macromolecular substances produced by the hydrosilylation reaction. Cured resins with a high crosslinking density and a high molecular weight of vinyl silicone residues had a lower amount of oil bleed. In addition, a low Si-H content also reduced the amount of oil bleed.

Graphical abstract

Keywords

oil bleed / crosslinking density / molecular weight / vinyl silicones / hydrosilicones

References

[1] Sim L C, Ramanan S R, Ismail H, Seetharamu K N, Goh T J. Thermal characterization of Al₂O₃ and ZnO reinforced silicone rubber as thermal pads for heat dissipation purposes. Thermochimica Acta, 2005, 430(1-2): 155–165

[2] Rachel G. Thermal interface materials: Opportunities and challenges for developers. Translational Materials Research, 2015, 2(2): 020301

[3] Kim E S, Kim E J, Shim J H, Yoon J S. Thermal stability and ablation properties of silicone rubber composites. Journal of Applied Polymer Science, 2008, 110(2): 1263–1270

[4] Jiang Q, Wang X, Zhu Y T, Hui D, Qiu Y P. Mechanical, electrical and thermal properties of aligned carbon nanotube/polyimide composites. Composites. Part B, Engineering, 2014, 56: 408–412

[5] Crawford B, Doherty A P, Spedding P L, Herron W, Proctor M. Viscosity of siloxane gum and silicone rubbers. Asia-Pacific Journal of Chemical Engineering, 2010, 5(6): 882–894

[6] Salam M H, El-Gamal S, El-Maqsoud D M, Abd Mohsen M. Correlation of electrical and swelling properties with nano free-volume structure of conductive silicone rubber composites. Polymer Composites, 2013, 34(12): 2105–2115

[7] Zha J W, Zhu Y H, Li W K, Bai J B, Dang Z M. Low dielectric permittivity and high thermal conductivity silicone rubber composites with micro-nano-sized particles. Applied Physics Letters, 2012, 101(6): 062905

[8] Zhou W Y, Wang C F, An Q L, Ou H Y. Thermal properties of heat conductive silicone rubber filled with hybrid fillers. Journal of Composite Materials, 2008, 42(2): 173–187

[9] Chen L F, Xie H Q. Silicon oil based multiwalled carbon nanotubes nanofluid with optimized thermal conductivity enhancement. Colloids and Surfaces. A, Physicochemical and Engineering Aspects, 2009, 352(1-3): 136–140

[10] Kemaloglu S, Ozkoc G, Aytac A. Properties of thermally conductive micro and nano size boron nitride reinforced silicon rubber composites. Thermochimica Acta, 2010, 499(1-2): 40–47

[11] Cheng J P, Liu T, Zhang J, Wang B B, Ying J, Liu F, Zhang X B. Influence of phase and morphology on thermal conductivity of alumina particle/silicone rubber composites. Applied Physics. A, Materials Science & Processing, 2014, 117(4): 1985–1992

[12] Mi Y N, Liang G Z, Gu A J, Zhao F P, Yuan L. Thermally conductive aluminum nitride-multiwalled carbon nanotube/cyanate ester composites with high flame retardancy and low dielectric loss. Industrial & Engineering Chemistry Research, 2013, 52(9): 3342–3353

[13] Li T, Chen J, Dai H Y, Liu D W, Xiang H W, Chen Z P. Dielectric properties of CaCu₃Ti₄O₁₂-silicone rubber composites. Journal of Materials Science Materials in Electronics, 2015, 26(1): 312–316

[14] Paul D R, Mark J E. Fillers for polysiloxane (“silicone”) elastomers. Progress in Polymer Science, 2010, 35(7): 893–901

[15] Mu Q H, Feng S G, Diao G Z. Thermal conductivity of silicone rubber filled with ZnO. Polymer Composites, 2007, 28(2): 125–130

[16] Ventura I A, Rahaman A, Lubineau G. The thermal properties of a carbon nanotube-enriched epoxy: Thermal conductivity, curing, and degradation kinetics. Journal of Applied Polymer Science, 2013, 130(4): 2722–2733

[17] Wang X J, Zhang L Z, Pei L X. Thermal conductivity augmentation of composite polymer materials with artificially controlled filler shapes. Journal of Applied Polymer Science, 2014, 131(8): 39550

[18] Gan L, Shang S M, Yuen M C W, Jiang S X, Luo N M. Facile preparation of graphene nanoribbon filled silicone rubber nanocomposite with improved thermal and mechanical properties. Composites. Part B, Engineering, 2015, 69: 237–242

[19] Ionita M, Pandele A M, Crica L, Pilan L. Improving the thermal and mechanical properties of polysulfone by incorporation of graphene oxide. Composites. Part B, Engineering, 2014, 59: 133–139

[20] Ji T, Zhang L Q, Wang W C, Liu Y, Zhang X F, Lu Y L. Cold plasma modification of boron nitride fillers and its effect on the thermal conductivity of silicone rubber/boron nitride composites. Polymer Composites, 2012, 33(9): 1473–1481

[21] Wu L K, Ying J, Chen L T. Improvement of thermal conductivity of silicone by carbon nanotube array (CNTA). Advanced Materials Research, 2014, 1061-1062: 96–99

[22] Zhou W Y, Qi S H, Tu C C, Zhao H Z, Wang C F, Kou J L. Effect of the particle size of Al₂O₃ on the properties of filled heat-conductive silicone rubber. Journal of Applied Polymer Science, 2007, 104(2): 1312–1318

[23] Zhou W Y, Yu D M, Wang C F, An Q L, Qi S H. Effect of filler size distribution on the mechanical and physical properties of alumina-filled silicone rubber. Polymer Engineering and Science, 2008, 48(7): 1381–1388

[24] Zhou W Y, Qi S H, Zhao H Z, Liu N L. Thermally conductive silicone rubber reinforced with boron nitride particle. Polymer Composites, 2007, 28(1): 23–28

[25] Zou H, Zhang L Q, Tian M, Wu S Z, Zhao S H. Study on the structure and properties of conductive silicone rubber filled with nickel-coated graphite. Journal of Applied Polymer Science, 2010, 115(5): 2710–2717

[26] René S, Stefan R L, Katrin A, Martina B, André B, Thomas G. Transparent silicone calcium fluoride nanocomposite with improved thermal conductivity. Macromolecular Materials and Engineering, 2015, 300(1): 80–85

[27] Shang S M, Gan L, Yuen M C W, Jiang S X, Luo M N. Carbon nanotubes based high temperature vulcanized silicone rubber nanocomposite with excellent elasticity and electrical properties. Composites. Part A, Applied Science and Manufacturing, 2014, 66: 135–141

[28] Das A, Kasaliwal G R, Jurk R, Boldt R, Fischer D, Stöckelhuber K W, Heinrich G. Rubber composites based on graphene nanoplatelets, expanded graphite, carbon nanotubes and their combination: A comparative study. Composites Science and Technology, 2012, 72(16): 1961–1967

[29] Wang Q, Gao W, Xie Z M. Highly thermally conductive room-temperature-vulcanized silicone rubber and silicone grease. Journal of Applied Polymer Science, 2003, 89(9): 2397–2399

[30] Stein J, Lewis L N, Gao Y, Scott R A. In situ determination of the active catalyst in hydrosilylation reactions using highly reactive Pt(0) catalyst precursors. Journal of the American Chemical Society, 1999, 121(15): 3693–3703

[31] Lweis L N, Colborn R E, Grade H, Bryant G L Jr, Sumpter C A, Scott R A. Mechanism of formation of platinum(0) complexes containing silicon-vinyl ligands. Organometallics, 1995, 14(5): 2202–2213

[32] Zhao M, Feng Y K, Li G, Li Y, Wang Y L, Han Y, Sun X J, Tan X H. Synthesis of an adhesion-enhancing polysiloxane containing epoxy groups for addition-cure silicone light emitting diodes encapsulant. Polymers for Advanced Technologies, 2014, 25(9): 927–933

[33] Zhao M, Feng Y K, Li G, Li Y, Wang Y L, Han Y, Sun X J, Tan X H. Preparation and performance of phenyl-vinyl-POSS/addition-type curable silicone rubber hybrid material. Journal of Macromolecular Science, Part A: Pure and Applied Chemistry, 2014, 51(8): 639–645

[34] Zhao M, Feng Y K, Li G, Li Y, Wang Y L, Han Y, Sun X J, Tan X H. Fabrication of siloxane hybrid material with high adhesion and high refractive index for light emitting diodes (LEDs) encapsulation. Journal of Macromolecular Science, Part A: Pure and Applied Chemistry, 2014, 51(8): 653–658

[35] Gan L, Shang S M, Jiang S X. Impact of vinyl concentration of a silicone rubber on the properties of the graphene oxide filled silicone rubber composites. Composites. Part B, Engineering, 2016, 84: 294–300

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