Fig. 2
Characterization of catalyzed thiopolymers. a Photographs of a crosslinker (EGDMA) and elemental sulfur and examples of molded objects of catalyzed thiopolymers. b Volume of gas produced during reactions of sulfur with crosslinkers, with (red) and without (green) catalysts. c Offset DSC traces of sulfur reacted with EGDMA. In the absence of catalyst, the melting of S8 crystals at ~120 °C is apparent. Inset photograph shows the color of the products (from left to right: 0, 1, and 5 wt% catalyst). d Offset PXRD patterns of sulfur reacted with EGDMA, in the absence of catalyst the diffraction of S8 crystals is apparent. e Reaction time plotted against catalyst loading at 135 °C. Asterisk (*) indicate uncatalyzed DIB and DCPD took between 12 and 24 h (unobserved), plotted as 18 h. f The yield of open reactions performed at 135 °C, with (red) or without (green) 1 wt% Zn(DTC)2 catalyst. Error bars given for standard deviation of 3 repeats. g Glass transition temperature of insoluble sulfur-squalene polymers as a function of Zn(DTC)2 catalyst loading, plotted as the average of three parallel reactions
