Sylgard® Mixing Study

Abstract

Sylgard® 184 and Sylgard® 186 silicone elastomers form Dow Corning® are used as potting agents across the Nuclear Weapons Complex. A standardized mixing procedure is required for filled versions of these products. The present study is a follow-up to a mixing study performed by MST-7 which established the best mixing procedure to use when adding filler to either 184 or 186 base resins. 2 The most effective and consistent method of mixing resin and curing agent for three modified silicone elastomer recipes is outlined in this report. For each recipe, sample size, mixing type, and mixing time was varied over 10 separate runs. The results show that the THINKY™ Mixer gives reliable mixing over varying batch sizes and mixing times. Hand Mixing can give improved mixing, as indicated by reduced initial viscosity; however, this method is not consistent.

Long-Term Thermal Aging of Modified Sylgard 184 Formulations

“…Although the standard mixing ratio of 10:1 resin to hardener produces a material that exhibits hyperelasticity, high surface adhesion, and low Young’s modulus, these properties can be altered for a variety of applications by increasing or decreasing the mixing ratio [ 13 , 14 ]. In addition to altering the mixing ratio, many complementary products exist for changing viscosity and curing times [ 15 ]. Accelerating the curing time is routinely performed by curing at higher temperatures [ 16 , 17 , 18 ]; however, for many applications this approach is not feasible because the components surrounding Sylgard 184 can be heat-sensitive.…”