Shear and extensional flows as drivers for the crystallisation of isotactic polypropylene

Autor:	B. Knogler, K. Buchmann, M. Obadal, Susana Filipe
Rok vydání:	2009
Předmět:	Polypropylene Materials science Molar mass Condensed Matter Physics law.invention chemistry.chemical_compound Shear (geology) chemistry Rheology law Tacticity Molar mass distribution Crystallite Physical and Theoretical Chemistry Crystallization Composite material
Zdroj:	Journal of Thermal Analysis and Calorimetry. 98:667-674
ISSN:	1572-8943 1388-6150
Popis:	The article addresses the relevance of shear and uniaxial extensional flow behaviour on the crystallisation of isotactic polypropylenes differing in terms of molar mass distribution (MMD). The importance of combining several experimental techniques, namely rheological, thermal and microscopic, to follow the response of the material arising from the application of given processing conditions, is here demonstrated. Systems with a broader MMD possessing even residual amounts of high molar mass (M M) tails were shown to be more prone to develop β-phase crystallites. The latter effect was seen to be a consequence of the application of a step shear at a temperature for which the formation of β-phase is known to be preferential.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::fc42901315f03145f96241834f0dd745 https://doi.org/10.1007/s10973-009-0517-2 Zobrazit plný text záznamu Plný text ve formátu PDF