The kinetics of isothermal crystallization has been studied for Na+

Mn2+ and Ca2+ ionomers based on maleic anhydride graft polypropylene(PP g MAH) by DSC

compared with pure PP and PP g MAH.Avrami equation was valid for analyzing the experimental data.The fact that Avrami exponents close to three for all the samples implied the mode of PP crystallization was not changed by the solid graft modification.The introduction of ions increased the crystallization rate(characterized by the reciprocal of the half-life of the crystallization

t-11/2) dramatically.At the same time

the increase of neutralization also increased the crystallization rate.The reducing of the interfacial free energies of the side surfaces of the nucle σe

calculated from Hoffman theory

bu the anhydride group and ions had the same trend with the results of Avrami equation.