Title | Enhancement to the rate-dependent mechanical behavior of polycarbonate by incorporation of triptycenes |
Publication Type | Journal Article |
Year of Publication | 2008 |
Authors | Tsui, NT, Yang, Y, Mulliken, AD, Torun, L, Boyce, MC, Swager, TM, Thomas, EL |
Journal | Polymer |
Volume | 49 |
Pagination | 4703–4712 |
Date Published | oct |
ISSN | 00323861 |
Keywords | polycarbonate triptycene blend polydispersity comp |
Abstract | The tensile and compressive properties of triptycene-polycarbonates were tested over 6 orders of magnitude in strain rate. Initially we studied a low mol. wt., low triptycene content PC blended with Iupilon PC and then a series of higher mol. wt., higher triptycene content polymers. The PC blend with only 1.9 wt.% triptycene displayed up to 20% increase in modulus and up to 17% increase in yield strength with elongations over 80% as compared to the Iupilon PC. The higher mol. wt. T-PCs (up to 26 wt.% triptycene) exhibited improvements in modulus by over 20% and improvements in compressive strengths by nearly 50% at both low and high strain rates without any apparent sacrifice to ductility, as compared to Iupilon PC. All samples contg. triptycene units retained transparency and exhibited no signs of crystallinity or phase sepn. Moreover, both the blends and triptycene-PC copolymers displayed significantly altered dynamic mech. spectra, specifically, the emergence of a pronounced, new $\beta$' relaxation approx. 75° above the traditionally obsd. $\beta$ relaxation in PC (approx. -100°). The enhancement of the mech. properties obsd. provides valuable insights into the unique packing and interactions during plastic flow induced by the presence of triptycene units. [on SciFinder(R)] |
URL | http://linkinghub.elsevier.com/retrieve/pii/S003238610800712X |
DOI | 10.1016/j.polymer.2008.08.038 |