Phenolic resins thermal conductivity

To ensure that a liquid metal is completely disintegrated into droplets before the initiation of any solidification in the gap, the heat transfer between the liquid metal and the rolls must be minimized. Materials with low thermal conductivity and poor wetting properties have been found to have the most significant effect on reducing the heat transfer. Epoxy and phenolic resin coatings have been applied to... 

Fire resistance is an important property of phenolic resins. The combination of phenolic resin with Expancel expandable microspheres leads to many useful products. Composites for high speed train interiors take advantage of the light weight, excellent fire rating, and very low thermal conductivity. Polyester filled with aluminum hydroxide is an alternative solution for train interior materials. The resin and filler can be easily processed when viscosity regulating additives are added. 

The thermal conductivity of a mixture is nearly proportional to the volume percentage of each component. Wood-flour-filled phenolic has a higher thermal conductivity than the pure resin, but the conductivity of this composite is still low enough to justify its use as the handle to a teapot. This composite can also withstand temperatures up to 100°C sufiiciently well to give the handle a reasonable service life. For parts subjected to higher temperatures, asbestos-filled phenolic is a better choice. It can be used as the insulating connection to an electric iron, for example. 

Cold wall heats of ablation values ranged between 7700 and 13,800 Btu/lb. The best performance was obtained with the heterocyclic polyimide and polybenzimidazole and the aromatic polyphenylene resins, all of which exceed the heat of ablation for the widely used phenol formaldehyde (phenolic) resin. The superior charring characteristics of these polymers contributed greatly to their high heats of ablation. The various plastic materials, with their inherently low thermal conductivities, greatly restricted the flow of heat from the surface region into the specimen substrate. 

Friction materials. Brake linings and clutch facings use 2 percent of the phenolic resin market. The resin is compounded with rubber for toughness mica, talc, and glass for friction and powdered metal for thermal conductivity to prevent over-heating. 

In another study, Bafekipour and et al. [60] designed and fabricated functionally graded carbon nanofiber-phenolic nanocomposites (FGN) using four different gradient patterns and the same overall carbon nanofiber (CNF) content and geometry. The composition across the thickness of the samples was controlled in eight 600-mm-thick layers with clear interlayer boundaries. They observed that the incorporation of CNF into the phenolic matrix increased the thermal conductivity of the resin. For example, the thermal conductivity of the matrix increased 28.1, 49.5 and 90.4 % with the incorporation of 2, 4 and 16 wt% CNF, at room temperature, respectively. The authors attributed this thermal conductivity enhancement in the phenolic matrix is due to the formation of inter-connected mesh of CNFs. 

Thermal decompositions have been studied most effectively by mass spectroscopic thermal analysis, thermogravimetric analysis, and electrical conductivity. Several analytical characterizations of phenolic resins have recently been reported, making use of a variety of properties, including expansion coefficients, " specific heat capacity, ultrasonic properties, dipole moments, and laser light scattering. Recently, high-temperature properties of reinforced phenolic components have been studied by Goetzel. ... 

Fuel cells Composite glasslike carbon with graphite powder as a filler was developed to increase mechanical strength and flexibility as well to increase electrical and thermal conductivity. Porous carbon with homogeneous sizes and a uniform distribution of pores can be used as an electrode in fuel cells [195]. An electric capacitor using the active carbon fiber derived from Kynol-type phenol resin is also used. 

Thermal characteristics are also important in numerous industrial processes, and thus the development of composites with high thermal conductivity and a low coefficient of thermal expansion is important to achieve effective heat conduction (Kim et al., 2007). The use of some reinforcements such as carbon nanotubes, carbon fibers, nano silica powders, metal particles, boron nitrite and glass fibers can improve the thermal conductivity of phenolic composites (Kim et al., 2007 Simitzis et al., 2011 Srikanth et al., 2010). Kim et al. (2007) demonstrated that the homogeneous dispersion of 7 wt% carbon nanotubes in a phenolic resin acted as an effective thermal bridge between adjacent carbon fibers and enhanced the thermal conductivity (393 W m-i K-i). 

Kim Y A, Kamio S, Tajiri T, Hayashi T, Song S M, Endo M, Terrones M and Dresselhaus M S (2007), Enhanced thermal conductivity of carbon fiber/phenolic resin composites by the introduction of carbon nanotubes , Appl Phys Lett, 90, 093125(1)-093125(3). 

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