The Impact of Regiodefects on the Melt-Memory of Isotactic Polypropylene.

Autor: Cicolella A; Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Monte S.Angelo, Via Cintia, I-80126, Italy.; Scuola Superiore Meridionale, Largo San Marcellino 10, Napoli, I-80138, Italy., De Rosa C; Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Monte S.Angelo, Via Cintia, I-80126, Italy., Sepe E; Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Monte S.Angelo, Via Cintia, I-80126, Italy., De Stefano F; Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Monte S.Angelo, Via Cintia, I-80126, Italy., Giordano A; Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Monte S.Angelo, Via Cintia, I-80126, Italy., Scoti M; Dipartimento di Scienze Chimiche, Università di Napoli 'Federico II', Complesso Monte S.Angelo, Via Cintia, I-80126, Italy.
Jazyk: angličtina
Zdroj: Macromolecular rapid communications [Macromol Rapid Commun] 2024 Aug; Vol. 45 (16), pp. e2400233. Date of Electronic Publication: 2024 May 28.
DOI: 10.1002/marc.202400233
Abstrakt: The memory of crystalline phase in the melt of isotactic polypropylene (iPP) in regiodefective samples of iPP characterized by different concentrations regiodefects, constituted by secondary 2,1 propene units, is studied. The self-nucleation (SN) experiments have demonstrated that the presence of 2,1 regiodefects produces a strong memory of the crystalline phase in the melt that persists up to temperatures much higher than the melting temperature. The extension of the heterogeneous melt (domain II) containing self-nuclei increases with increasing the concentration of regiodefects. The higher the concentration of regiodefects the higher the temperature at which the self-nuclei are dissolved and the homogeneous melt is achieved. This demonstrates that a strong memory of the crystalline phase of iPP in the melt exists not only in copolymers with noncrystallizable bulky comonomeric units rejected from the crystals but even when small defects are largely included in the crystals.
(© 2024 Wiley‐VCH GmbH.)
Databáze: MEDLINE
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