Structural analysis of oriented poly(ε‐caprolactone) including CaCO 3 particles with 13 C solid‐state NMR

The results of a study of the relation between the oriented structure and drawn Poly(ε‐caprolactone) specimens including CaCO 3 particles and their dynamic mechanical properties are presented. The loss elasticity, E″, showed almost the same curve for both undrawn sheets and drawn sheets as a function of CaCO 3 content. On the other hand, the storage modulus, E′, of drawn sheets increased nonlinearly with increasing CaCO 3 content, and their curve showed lower E′ values than those of undrawn sheets. By simulation of 13 C CP NMR spectra of drawn PCL/CaCO 3 sheets, both oriented and unoriented components were observed. The distribution parameter, p, of drawn PCL/CaCO 3 sheets was 13°, which was larger than those (8°) of drawn PCL. Further, the fraction of the unoriented component increased with increasing CaCO 3 content. Thus, adding CaCO 3 particles into the PCL, the arrangement of the oriented component was disturbed and decreased. In addition, from the line shape analyses of 13 C CP MAS NMR spectra, four peaks were obtained in not only undrawn sheets but also in drawn sheets of both PCL and PCL/CaCO 3 compounds. Besides, structural change occurred at only drawn PCL/CaCO 3 sheets. Therefore, the change in dynamic mechanical properties observed only for drawn PCL/CaCO 3 sheets were strongly dependent on the orientational structure, which was formed under shear stress of the stretching drawn process. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2376–2382, 2001