Mechanical Properties of Adhesives, Sealants and Coatings

The rise of electric vehicles and driver aids along with the proliferation of electronic sensors and safety features point towards continued growth in automotive electronics. Due to their lightweight, functional properties, adhesives, encapsulants and coatings will be of increased importance for use in structural bonding, as well as in non-structural applications for electronic, optical and mechanical components in electric vehicle manufacturing. Read more about the properties, uses and future developments of these compounds as they pertain to the automotive industry.

To verify vehicle scanner accuracy, Phoenix Scientific Inc. needed a reference surface accurately representing the test pavement, with uniform flatness. Machining or transporting such a precise surface was difficult and costly. Their solution: applying a self-leveling epoxy (EP29LP) to harden the beam, using a 'prepared beam method' to achieve the required flatness.

EP39MAOHT blends a low viscosity and low exotherm, making it particularly well suited for large volume potting and castings. This video demonstrates this system’s mixing and flow properties. This room temperature curing system has excellent thermal conductivity and electrical insulation properties. It offers chemical resistance to water, fuels and hydraulic fluids as well as many acids and bases.

Because of its outstanding strength and other physical properties, Master Bond Supreme 10HT has been selected for use in several published research studies in the aerospace, electronics, OEM, materials science and more.

Forming reliable bonds between different materials can be challenging because there can be large variations in CTE's (coefficients of thermal expansion). Adhesive compounds play a critical role in the fabrication of assemblies for electronic, optical and mechanical systems. Learn more about typical CTE's for various chemistries such as epoxies and silicones, how fillers can be used to modify CTE, why CTE is dependent on temperature and much more. Specific case studies illustrate the thermal compounds used.

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 700-800 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 100 gram 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 color. MasterSil 153AO is generically low outgassing, contains no solvents, has a low linear shrinkage upon curing and is RoHS compliant.