Preliminary study on the possible new modification of isotactic polypropylene crystallized under high pressure

Isotactic polypropylene (iPP) has complex polymorphic structures. It can crystallize in at least four different modifications, termed α, β, γ and δ, under different crystallization conditions. The modifications of iPP and their transitions have attracted much attention over the years. Studies on the relationships between the modifications and the possibility of formation of new modification are significantly important to investigation on the relationships between structure and properties of iPP. In this note, the