Tailoring properties and processing of Sylgard 184: Curing time, adhesion, and water affinity

ABSTRACT The curing time, surface adhesion, and water absorption characteristics of Sylgard 184 were modified through the addition of catalysts and fillers. Incorporation of small amounts of a platinum‐based Karstedt catalyst greatly decreased curing time at room temperature, whereas the addition of talcum powder (talc), polytetrafluoroethylene (PTFE), and NaY zeolite fillers changed surface adhesion and functionality of Sylgard 184. Fourier‐transform infrared spectroscopy (FT‐IR), rheological and mechanical tests (tensile strength and hardness) were used to quantify the acceleration in the curing time. The surface adhesion was evaluated for aluminum and glass‐like substrates using a 90° peel‐off test. The interaction between fillers and Sylgard was studied by molecular dynamics simulations, which showed the interaction between NaY and Sylgard is greater than that for PTFE. Water absorption studies indicated that 10 wt% NaY added to Sylgard 184 helped to improve water absorption, whereas incorporation of talc had the opposite effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48530. Representation of peel‐off test on an aluminum substrate for a Sylgard 184 sample containing PTFE. The graph shows peel‐off strength as a function of the filler type that was incorporated into Sylgard 184.