Alkylated styrene ionomers with variable length spacers. I. Synthesis

Abstract

Two analogous series of ionomer precursors based on 4‐substituted styrene copolymers were prepared with substituents R = ‐(CH2)nCO2Me (n = 1, 5, 10), or R = ‐O(CH2)nCO2Me (n = 1, 4, 10), and degrees of substitution from 10 to 15 mol%. The synthesis of the alkyl series compounds involved either chloromethylation of polystyrene or bromoalkylation via lithiation of a styrene‐4‐bromostyrene copolymer, followed by conversion to the nitriles. Methyl esters were then produced by reaction of the nitriles with methanol/HCl gas. The ether series compounds were obtained directly by reacting a styrene‐4‐hydroxystyrene copolymer with the methyl esters of the corresponding ω‐bromoaliphatic carboxylic acids in a Williamson ether‐type synthesis.

Small-angle x-ray scattering investigations of ionomers with variable-length side chains

“…The extent of ionization was confirmed by NMR analysis of the hydrolyzed polymers. 27 Prior to molding, the precipitated ionomers were dried for 24 h at 60 °C in a vacuum oven. The SAXS samples were compression molded from approximately 0.1 g of the dried polymers at 30 °C above their respective cluster glass transition temperatures, T1,,.…”