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The polymorphic behavior of syndiotactic polypropylene (s-PP) crystallized from the melt under different conditions was investigated by means of WAXD and DSC. The isothermal melt crystallization of s-PP proceeded in form I at tc≥ 110℃ and in form Ⅱ at tc≤110 ℃ s-PP crystallized nonisothermally from the melt was the mixture of forms and . With increasing the cooling rate (a), the content of form increased, and the content of form decreased. On heating, at 10 K/min, of quenched s-PP, it crystallized in form at t≤70 , continuing heating resulted in form form transition, which was an endothermal process.
The polymorphic behavior of syndiotactic polypropylene (s-PP) crystallized from the melt under different conditions was investigated by means of WAXD and DSC. The isothermal melt crystallization of s-PP proceeded in form I at tc ≥ 110 ° C and in form II at tc ≤110 ° C s-PP crystallized nonisothermally from the melt was the mixture of forms and. With increasing the cooling rate (a), the content of form increased, and content of form decreased. On heating, at 10 K / min, of quenched s-PP, it crystallized in form at t≤70, continuing heating result in form transition, which was an endothermal process.