Potential and limits of dynamic mechanical analysis as a tool for fracture resistance evaluation of isotactic polypropylenes and their polyolefin blends
2004; Wiley; Volume: 93; Issue: 4 Linguagem: Inglês
10.1002/app.20606
ISSN1097-4628
AutoresC. Grein, Klaus Bernreitner, Markus Gahleitner,
Tópico(s)Mechanical Behavior of Composites
ResumoAbstract Potential and limits of dynamic mechanical analysis (DMA) as a tool for fracture resistance evaluation of isotactic polypropylenes and their polyolefin blends are presented. A minimum of information about the materials under investigation is a prerequisite to interpret the DMA traces in a right way. Although DMA is, in general, a powerful method to rank materials in term of toughness, care should be taken with (1) nucleated materials (where both intensity and strength of molecular relaxations need to be taken into account in material evaluation) and with (2) visbroken (i.e., peroxyde treated) grades. Except for these cases, the strengths of the principal or secondary molecular relaxation evaluated by DMA and the Charpy impact toughness correlate quantitatively when all the grades of a series exhibit unstable crack propagation. When changes in the macroscopic mode of fracture or in blend morphology occur, only qualitative correlations remain possible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1854–1867, 2004
Referência(s)