Crystallization of a (1-butene)-ethylene copolymer in phase I directly from the melt in nanocomposites with montmorillonite.

Nanocomposites based on a copolymer of 1-butene and ethylene filled with montmorillonite (Cloisite 15A) were studied, obtaining for the first time crystallization from the melt directly into phase I. The polymorphism of the polymer and the dispersion of the filler in the matrix were investigated. The effect of the compatibilizer (PB-g-MA) on these properties was also singled out. The dramatic increase in the rate of the II --> I phase transition due to montmorillonite was attributed to the alteration in the phase stability diagram of the matrix, due to the introduction of defects and to induction of local pressure on the crystalline domains.