Carboxylate‐containing chain‐extended polyurethanes

Abstract

Polyurethanes based on methylene bis(p‐phenyl isocyanate), bis(hydroxymethyl) propanoic acid, and poly (tetramethylene oxide) were synthesized, and their morphology and physical properties investigated. The acid polyurethanes exhibited very poor phase separation and mechanical properties, but upon neutralization with alkali metals phase separation improved dramatically and the materials resembled tough elastomers. The choice of cation played a much less important role than hard segment content in determining morphology and properties. Small‐angle x‐ray scattering patterns of these ionic polyrethanes exhibit two peaks, one characteristic of scattering between the hard and soft domains and the other reflecting scattering from aggregates of ionic groups residing within the hard domains. While ionic aggregation is the primary driving force for phase separation in these materials, their morphology more closely resembles that for nonionic polyurethanes than that for conventional ionomers, because the ionic groups exist in blocks composed primarily of rigid diisocyanate residues.

Investigations on polyurethane ionomers. II. 3,4-dihydroxycinnamic acid-based anionomers

“…For example, C 1 Na and C 1 Zn sulting in the increased intensity of the band at 1600 cm 01 . The intensity of the carbonyl band at denote the sodium and the zinc anionomers of C 1 H-NMR spectra of the polyurethane were recorded using DMSO-d 6 solvent and are given in the chain extender and the aliphatic C|C of the chain extender absorbs from 6 to 8 ppm. The pro- Figures 1-4.…”

“…Polyurethane ionomers are synthesized predominantly by using an ionic diiso-EXPERIMENTAL cyanate or an ionic diol at the chain-extension stage and by postmodification of a preformed polyureMaterials thane. In the former case, polyurethane anionomers [1][2][3][4][5][6][7][8] (with carboxylic, sulfonic, and phosphoric Poly(propylene glycol) of molecular weight 1000 (PPG 1000 ), polycaprolactone diol of molecular acid groups), cationomers, [9][10][11][12][13][14][15][16] and zwitterionomers 17-21 were studied in great detail. In the latter weights 530, 1250, and 2000 (PCL 530 , PCL 1250 , and PCL 2000 ), poly(ethylene glycol) of molecular case, polyurethanes were treated with NaH/NaOH and subsequently reacted with 1,3-propanesultone weight 1000 (PEG 1000 ), and poly(tetramethylene oxide)glycol of molecular weight 1000 (PTMG 1000 ) to give zwitterionomers.…”

Synthesis and properties of polyurethane ionomers based on carboxylated polycaprolactone

“…In contrast, a better phase separation resulted in a polyurethane ionomer with ionization in the hard segment. 10 It is interesting that endotherms at about 170°C were observed on the trace of the ionomers showing that the hard segment in the ionomer system possesses a regular array. As we expected, that ionization of the soft segments did not disturb this regular structure, small crystallites or short range ordered structure could exist in the hard segment of these PU ionomers.…”

Carboxylated polyurethane anionomers and their composites with polypyrrole

“…2 Some recent studies were focused on polyurethane anionomers with ionic groups incorporated into the hard segments, mostly by using dimethylolpropionic acid as chain extender. [3][4][5][6][7] Previously we synthesized some polyesterpolyurethane anionomers with carboxylate groups on urethane nitrogen atoms 8 by a two-step modification of a nonionic polymer, 9 and some properties of these anionomers were reported. 8 Here we describe more mechanical and electrical properties of above the polymers and their testing for synthesis of some composites with polypyrrole.…”

“…26,27 A diaphragmatic procedure gave conducting polypyrrole-Nafion composite films through chemical polymerization of pyrrole. 28 Conductive molecular composites were prepared by immersion of pyrrole-swollen films of poly(ethylene terephtalate) 29 or sulfonated polystyrene 30 in aqueous FeCl 3 . In the present research the latter chemical method of in situ polymerization of pyrrole was used to obtain conductive polyurethane anionomer/polypyrrole composites.…”