We report a simple, serendipitous, two step mediation that overcomes the polyaddition threshold of castor oil during polyurethane formation. The mediation facilitates formation of polyurethane systems directly from castor oil without triricinolein chain extension or the use of supplementary hydroxyl compounds. The mediation involves refluxing castor oil with n-Butyl lithium in the presence of a solvent followed by water addition. We demonstrate the effectiveness of this mediation by successfully generating two important polyurethane systems (foam and coating) from castor oil. We identify that the mediation introduces two new compounds in castor oil namely, a lithiated diglyceride and a lithium salt of fatty acid. We characterize the new polyurethane synthesized for their hard-soft segmented morphology, glass transition temperature, and thermomechanical properties. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43964.

We conducted transport studies of a common solvent (toluene) in its condensed state, through a model hard-soft segmented polyurethane-clay nanocomposite. The solvent diffusivity is observed to be non-monotonic in a functional relationship with a filler volume fraction. In stark contrast, both classical tortuous path theory based geometric calculations and free volume measurements suggest the normally expected monotonic decrease in diffusivity with increase in clay volume fraction. Large deviations between experimentally observed diffusivity coefficients and those theoretically estimated from geometric theory are also observed. However, the equilibrium swelling of a nanocomposite as indicated by the solubility coefficient did not change. To gain an insight into the solvent interaction behavior, we conducted a pre- and post swollen segmented phase analysis of pure polymers and nanocomposites. We find that in a nanocomposite, the solvent has to interact with a filler altered hard-soft segmented morphology. In the altered phase separated morphology, the spatial distribution of thermodynamically segmented hard blocks in the continuous soft matrix becomes a strong function of filler concentration. Upon solvent interaction, this spatial distribution gets reoriented due to sorption and de-clustering. The results indicate strong non-barrier influences of nanoscale fillers dispersed in phase segmented block co-polymers, affecting solvent diffusivity through them. Based on pre- and post swollen morphological observations, we postulate a possible mechanism for the non-monotonic behaviour of solvent transport for hard-soft segmented co-polymers, in which the thermodynamic phase separation is influenced by the filler.

We elucidate the influences of direct hydration on morphological heterogeneity of the class of hard-soft segmented copolymers by experimenting on three model members selected from this group. For influences on...