Using this method, the sulfur and CPD were heated for a total of 60 minutes before the black liquid product was transferred to a silicone mold and cured in an oven at 140 °C for 24 hours. This method was used to produce polymers ranging from 50 wt% to 80 wt% sulfur, however, for most experiments 1.5 g of CPD was used, corresponding to 67 wt% sulfur and a sulfur to CPD molar ratio of approximately 4. This polymer is referred to as 67-poly(S-r-CPD) where the first number corresponds to the weight percent of sulfur and r denotes a random polymerization of the sulfur (S) and cyclopentadiene (CPD) comonomers.