Web Release Date: November 29,
Synthesis and Properties of Amidoimide Dendrons and Dendronized Cellulose Derivatives
and
Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Kyoto 615-8510, Japan, and Division of Forest & Biomaterials Science, Graduate School of Agriculture, Kyoto University, Yoshida Campus, Kyoto 606-8502, Japan
Received August 17, 2007
Revised Manuscript Received October 17, 2007
Abstract:
First and second generation amidoimide dendrons (G1-a-II-G1-c-II and G2-a-II-G2-c-II) having
branched alkyl periphery and focal carboxyl functionality were synthesized via a convergent pathway and
incorporated into ethyl cellulose. Dendronized ethyl cellulose derivatives (2a-c, 3a-c) were synthesized in good
yield by the reaction of the terminal carboxyl moiety of various dendrons with residual hydroxy groups of ethyl
cellulose (1; degree of substitution with ethyl group (DSEt), 2.69). 1H NMR spectra and elemental analysis were
employed to determine the degree of esterification (DSEst) of the resulting polymers. The presence of the peak
characteristic of the C=O group in the FTIR spectra accomplished further evidence for the incorporation of
dendritic moieties into ethyl cellulose. All of the derivatives (2a-c, 3a-c) were soluble in chloroform and methanol,
and the solubility window narrowed in going from G1- to G2-derivatized polymers. The onset temperatures of
weight loss of 2a-c (295-325 
C) and 3a-c (312-320 C) in air were slightly higher than 294 C, indicating
that the thermal stability was retained upon dendron functionalization. Free-standing membranes of 1 and 2a-c
were fabricated, and 2a-c exhibited enhanced permselectivity for He/N2, H2/N2, CO2/N2, and CO2/CH4 gas pairs
as compared to 1.
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