The structural evolution of micromolded poly(ε-caprolactone)
(PCL) and its miscible blends with noncrystallizable poly(vinyl
methyl ether) (PVME) at the nanoscale was investigated as a function of
deformation ratio and blend composition using in situ synchrotron smallangle
X-ray scattering (SAXS) and scanning SAXS techniques. It was
found that the deformation mechanism of the oriented samples shows a
general scheme for the process of tensile deformation: crystal block slips
within the lamellae occur at small deformations followed by a stressinduced
fragmentation and recrystallization process along the drawing
direction at a critical strain where the average thickness of the crystalline
lamellae remains essentially constant during stretching. The value of the
critical strain depends on the amount of the amorphous component
incorporated in the blends, which could be traced back to the lower
modulus of the entangled amorphous phase and, therefore, the reduced network stress acting on the crystallites upon addition of
PVME. When stretching beyond the critical strain the slippage of the fibrils (stacks of newly formed lamellae) past each other
takes place resulting in a relaxation of stretched interlamellar amorphous chains. Because of deformation-induced introduction of
the amorphous PVME into the interfibrillar regions in the highly oriented blends, the interactions between fibrils becomes
stronger upon further deformation and thus impeding sliding of the fibrils to some extent leading finally to less contraction of the
interlamellar amorphous layers compared to the pure PCL / National Natural Science Foundation of China (21204088 and 21134006). This
work is within the framework of the RCUK/EPSRC Science Bridges China project of UK−China Advanced Materials Research Institute (AMRI).
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/6037 |
| Date | 10 September 2013 |
| Creators | Jiang, Z., Wang, Y., Fu, L., Whiteside, Benjamin R., Wyborn, John, Norris, Keith, Wu, Z., Coates, Philip D., Men, Y. |
| Source Sets | Bradford Scholars |
| Detected Language | English |
| Type | Article |
| Rights | © 2013 American Chemical Society. Full-text reproduced in accordance with the publisher’s self-archiving policy. This document is the Accepted Manuscript version of a Published Work that appeared in final form in Macromolecules, copyright © American Chemical Society after peer-review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/ma401052x. |
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