Equilibrium melting points of the low‐melting and high‐melting crystalline forms of trans‐1, 4‐polyisoprene

Equilibrium melting points in trans‐1,4‐polyisoprene were calculated from plots of crystallization temperature versus the experimentally measured melting points. The melting points were found to be 78 ± 1.7°C for the low‐melting crystalline form and 87 ± 1.3°C for the high‐melting form. Within the experimental error, melting points were independent of molecular weight above a number‐average weight of 33,000.