Insights into the mechanical properties of polymers by probing their functional group, and segmental motions using solid-state NMR
Predicting mechanical properties like ductility of polymers is, in general, a very difficult problem. However, it is well known that ductility of a single component amorphous glassy polymer is related to the inter- and intra-molecular cooperative segmental motions that occur in the glassy state. These, in turn, are related to the motions of functional groups in the repeat unit of the polymer. In the case of semi-crystalline polymers, the morphology, in addition is also very crucial to the mechanical property of the polymer.
In this talk the results from a study of functional group, and segmental motions in amorphous and semi crystalline polymers using solid-state nuclear magnetic resonance (SSNMR) will be presented. The separated local field NMR has been used to probe the functional group motion. The Center Band only Detection of Exchange (CODEX) experiments have been used to probe the slow segmental motions. We have carried out studies on polycarbonates and polysulfones which are purely amorphous. Results from the studies carried out on polyoxymethyline, a semi-crystalline polymer will be presented. In this study we have shown that the mechanical property is closely linked to the morphology of this polymer.