CONICET | Buscador de Institutos y Recursos Humanos

The effect of chemical cross-linkage on the crystallization of random ethylene-1-butene copolymers obtained from hydrogenation of model polybutadiene was studied by means of Differential Scanning Calorimetry. The copolymers were modified with different concentrations of organic peroxide in the molten state to generate different crosslinks level. Under isothermal conditions, the crystallization rate of the modified polymers decreased with the average molecular weight likewise to that observed in the copolymers. The original and modified polymers shows similar isothermal crystallization rate when they are compared at equivalent average molecular weights. Under no isothermal crystallization conditions, the crystallization temperature and enthalpy of the modified polymer decreased almost linearly with the peroxide concentration. The activation energy for crystallization increases with the peroxide concentration indicating that the increment in the crosslinking density restricts the crystallization process.