Silicone adhesive features high thermal conductivity and electrical insulation 19 May 2021

Master Bond MasterSil 153AO is an addition cured two part silicone with a self priming property. It has a high tensile lap shear strength, especially for a silicone. The system is thermally conductive and electrically insulating.

“The key feature of MasterSil 153AO is that it provides the ability to minimize stress, with no compromise on strength. Although it is not considered a structural adhesive, it provides a truly remarkable combination of flexibility and strength that other silicones do not provide,” says Rohit Ramnath, senior product engineer.

This silicone product has an elongation between 100% - 120%, and a tensile lap shear strength of 700 psi - 800 psi. It provides a thermal conductivity of 0.93 - 1.08 W/(m•K), a volume resistivity of more than 1014 ohm-cm, a coefficient of thermal expansion of 150-180 x 10-6 in/in/°C, and hardness of 65-75 Shore A. It is serviceable over the temperature range of -65°F to +400°F.

With an easy to use mix ratio of 1 to 1 by weight, MasterSil 153AO cures with the addition of moderate amounts of heat. For example, optimal cure schedule is overnight at room temperature followed by 2-4 hours at 135°F-185°F. Upon mixing, it retains its smooth paste consistency and minimal flow. It has a long working life of 4 to 6 hours for a 100g mass at 75°F.

This compound bonds well to a variety of substrates including metals, glass, ceramics, many plastics and silicone rubbers. It is available for use in kits, with sizes ranging from ½ pint, pint, quart to gallons. It is white in colour. MasterSil 153AO is generically low outgassing, contains no solvents, has a low linear shrinkage upon curing and is RoHS compliant.

Claire Aldridge Deputy Editor t: +44 (0) 1727 743 889

Having joined the magazine in 2012, Claire developed her knowledge of the industry through the numerous company visits, exhibitions and conferences she attended both in the UK and abroad.

Claire prides herself on keeping readers well informed and up to date with the latest industry news.