Models, experiments, and numerical simulation of isothermal crystallization of polymers

When a quiescent molten polymer is cooled below the equilibrium melting temperature, crystals (spherulites) appear and keep growing as long as the temperature ranges between the melting temperature and the glass transition temperature. The crystallization process depends upon temperature and crystalline microstructure. In particular, the reduction of the free volume and subsequent impingement between crystals influence both nucleation and growth rates of spherulites. Below the glass transition temperature, the polymer consists of crystal and amorphous phases. In the sequel we discuss a mathematical model for a bidimensional isothermal crystallization process which takes into account the nucleation, growth, and impingement of spherulites.