Abstract
Crystallization and melting, heat of fusion, and degree of crystallinity of syndiotactic PP were investigated. The double peak melting behavior was established for the partially crystalline polymer. A Hoffman-Weeks extrapolation resulted in equilibrium melting points of 151°C and 155°C for two polymers with relatively short syndiotactic sequences. The enthalpy of fusion was found to be 200 J/g, which corresponds to the value of isotactic pp. A very close correlation between the syndiotactic IR index and the heat of fusion was found. The melting point dependence on the sequence length was evaluated.