Hydrogen bonding in butadiene copolymers. I. Network formation

Abstract

SynopsisThe incorporation of comonomers bearing functional groups yields butadiene copolymers capable of hydrogen bonding. Three such butadiene-based materials were studied: methacrylic acid copolymers, 2-methyl-5-vinylpyridine copolymers, and stoichiometric mixtures of the acidic and basic copolymers. The elastic effects of intermolecular hydrogen bonding were determined by comparing the simple weighted average of the moduli of the parent copolymers with the observed modulus of their stoichiometric mixture. The results show that measurable increases in the moduli of the mixtures persist even above the glass temperature To, which is itself elevated in the mixtures. These increases may be treated as temperature-dependent temporary crosslinks.

The rheo‐optical and mechanical behavior of a systematic series of hard‐soft segmented urethanes

“…The degree to which hydrogen bonding affects the final material properties in these and other polymeric systems remains a source of much controversy. Some studies [20,21] have predicted and shown that break up of hydrogen bonding can be a source of mechanical loss while others [22,23,24] have noted only minimal changes between systems with and without hydrogen bonding. The usual segmented urethane systems do have considerable hydrogen bonding capabilities for both intra-and inter-segment interaction and many observed characteristics have been ascribed to them [12,25,26,27].…”