Dow Technical Article Describes Problem-Solving LSR for Flame-Retardant Automotive Electrical Connectors

Dow has published a technical article in the June 2024 edition of Rubber World magazine about a novel liquid silicone rubber (LSR) that is compatible with the fire-rated (FR) plastics used in automotive electrical connector housings. Unlike conventional LSRs, Dow SILASTIC™ 9212-50 won’t degrade prematurely from direct contact with FR plastics. This LSR formulation also retains its mechanical properties, flexibility, and dimensions in connector seals.

As Noel Mower Chang, Yenny Cubides, David Shawl, and Dongchan Ahn explain in Rubber World, most silicones are incompatible with FR plastics. The authors shared parts-testing research in which connector seals made of conventional LSRs degraded prematurely but non-silicone seals did not. To explain this difference, the authors theorize that the phosphorous-containing flame retardants in FR plastics migrate to silicone seals, cause thermal degradation, and increase compression set.

Dow developed SILASTIC™ 9212-50 to address this problem and improve the performance of automotive electrical connectors. As the technical article explains, this novel formulation provides both environmental sealing and electrical isolation, the separation of two systems or voltage levels. Its properties and processability are comparable to incumbent materials. As a drop-in replacement for non-silicones, SILASTIC™ 9212-50 succeeds where other LSRs do not.

Additional Resources Available

Last year, Dow provided a webinar called “LSR Solutions for Compatibility with Fire Resistant Plastics” as part of RDAbbott’s 2023 Webinar Series. A recording of this webinar is still available, so visit this link to learn more about how SILASTIC™ 9212-50 LSR supports the use of FR plastic materials for automotive connectors.

A copy of the Technical Data Sheet for SILASTIC™ 9212-50 LSR is also available by emailing Amy Congo at

More resources include:

If you’re interested in learning more about LSRs and other high quality silicone materials from Dow, contact us.