High-pressure-induced microstructural evolution and enhancement of thermal properties of nylon-6
2010 (English)In: Macromolecules, ISSN 0024-9297, E-ISSN 1520-5835, Vol. 43, no 24, 10512-10520 p.Article in journal (Refereed) Published
The transition behavior and thermal properties of nylon-6 at elevated pressure, p, have been established by in-situ thermal conductivity, κ, and heat capacity measurements. The glass transition temperature, Tg, of virgin nylon-6 is described well by the empirical equation Tg(p) = 319.60(1 + 1.90 p)0.24 (p in GPa and Tg in K). Moreover, isobaric heating in the 1−1.2 GPa range causes a cold-crystallization transition near 500 K. As a result, κ increased 15% whereas the heat capacity per unit volume decreased 7% slowly with time during 4 h annealing at 530 K. The transformation is associated with a significantly increased crystallinity, from 35% to 55−60%, and a pressure-induced preferred orientation and increased size for the lamellae of monoclinic α crystalline structure. This state has 8−10 K higher melting temperature and better formic acid resistance than that of virgin nylon-6. However, the results show no indication of cross-linking, as reported for similarly treated nylon-1010 and nylon-11, but instead chain scissoring.
Place, publisher, year, edition, pages
2010. Vol. 43, no 24, 10512-10520 p.
IdentifiersURN: urn:nbn:se:umu:diva-38807DOI: 10.1021/ma102273bISI: 000285429400049OAI: oai:DiVA.org:umu-38807DiVA: diva2:382552