Synthesis, Characterization, and Gas Permeation Properties

General Introduction
cellulose to decipher the impact of polar substituents on the structural characteristics
and hence the gas permeation parameters of the polymeric membranes. The
attenuated FFV of the polymer matrices has been described to be at the helm of the
decrement in the gas diffusion and solubility and consequently the decreased gas
permeability of the membranes. However, the increase in CO2 permselectivity was
not so evident and has been explicated by the author to be due to the unavailability of
the polar groups on the peripheries to interact with CO2. As discussed above,
spherical pendants are acknowledged to endow the polymers with enhanced local
mobility; therefore a blend of polar and spherical substituents was envisioned to
enhance permeability without loss in CO2 permselectivity. The interpolation of
moderately polar carbamoyl groups with spherical t-butyl periphery was accomplished
to bring in the improved gas permeability which was much more pronounced for the
carbamates of cellulose acetate while no significant decrease in CO2 permselectivity of
polymer membranes has been ascribed to the retained solubility selectivity.
The intricate features of synthetic strategies and mechanistic aspects of
cellulosic membranes explored in the present study are anticipated to lead us to new
frontiers of potential applications of this renewable energy resource.
Outline of the Thesis
The present dissertation delineates the synthesis of novel functional cellulose
ethers/esters, their characterization and investigation of various properties, and is
comprised of five chapters. A variety of functional substituents have been appended
to the backbone of different organosoluble cellulosics, i.e., ethyl cellulose, cellulose
acetate, and hydroxypropyl cellulose while the core synthetic strategy was to exploit
the residual hydroxy protons for the sake of derivatization. The incorporated
moieties encompass various silyl, perfluoroacyl, dendryl, carbamoyl, and
aminoalkanoyl groups, and the nature of the substituents was revealed to be of
considerable significance in determining the solubility and thermal characteristics of
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