Scanning Nanocalorimetry at High Cooling Rate of Isotactic Polypropylene

Autor:	Giuseppe Titomanlio, Felice De Santis, S.A. Adamovsky, Christoph Schick
Rok vydání:	2006
Předmět:	Exothermic reaction Materials science Polymers and Plastics Organic Chemistry Analytical chemistry Mesophase Heat capacity Phase formation law.invention Inorganic Chemistry Cooling rate Differential scanning calorimetry law Tacticity Polymer chemistry Materials Chemistry Crystallization
Zdroj:	Macromolecules. 39:2562-2567
ISSN:	1520-5835 0024-9297
DOI:	10.1021/ma052525n
Popis:	A wide set of cooling scans and subsequent melting behavior of isotactic polypropylene (i-PP) were investigated using differential scanning calorimetry and nanocalorimetry at very high cooling rate. The latter technique offers, indeed, the distinctive possibility to perform heat capacity measurements at rates of more than 1000 K/s, both in cooling and in heating, to characterize the crystallization. When the i-PP sample was solidified with cooling rate larger than 160 K/s, a novel enthalpic process was observed that was related to the mesomorphic phase formation. Furthermore, at cooling rates higher than 1000 K/s, the i-PP sample did not crystallize neither in the α nor in the mesomorphic form. The subsequent heating scan starting from −15 °C showed an exothermic event, between 0 and 30 °C, ascribed to the mesophase cold crystallization.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0ad4486bb082de90c7863c9ff46f8b7c https://doi.org/10.1021/ma052525n Zobrazit plný text záznamu