In our formulation, we add the corresponding diallyl imide in 5 mol% excess to TMPMP (1.05 [C=C]:1 [SH]), and 1 wt% diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) as the photoinitiator (Scheme 1A). The excess diallyl imide ensures a quantitative conversion the thiol groups, since free thiols can react with metals. In practice, resulting liquid resins possess a sufficient pot life (order of minutes or greater) such that transfer into heated (T ~ 80 °C) silicone molds did not result in any noticeable phase separation or solidification. We then irradiate at 405 nm UV light (5 mW/cm 2 ) and 80 °C for 10 minutes to polymerize the resin. Fourier-transform infrared (FTIR) spectroscopy confirms complete disappearance of the thiol peak (2569 cm -1 ) and nearly complete disappearance of the alkene peak (3092 cm -1 ), shown in Figure .