Preparation and some properties of nylon‐4,2

Abstract

SynopsisNylon 46 was synthesized from the salt of l,4-diaminobutane and adipic acid. High molecular weight polymers could be obtained by reaction for 1 hr at 215OC in a closed system and at least for 1 hr in UQCUO at a temperature in the range 290-305OC. The reactions at 29OOC were found to have taken place in the solid state and those at 305OC in the melt. The highest molecular weights ( M , ca. 45,000) were obtained by reaction at 290°C with a nylon salt with a pH of 7.8-8.0. The molecular weight characteristics were studied with end-group analysis, viscometry, light scgtering, and ultracentrifugation. The polymers were found to be gel-free and monodisperse (M,/Mn -1.15).Films could be cast from formic acid. From x-ray diffraction patterns, measured on such films, spacings of 3.74 and 4.30 A were calculated, whereas a long period of 66 A was also found. The infrared spectra showed all the usual amide bands of even-even polyamides. The melting temperature was found to vary between 283 and 319OC, depending on the thermal history of the sample. Water absorption measured on a cast film showed this to be very hygroscopic (7.5% at 65% RH), while a highly crystalline sample absorbed only little water (1.6% at 65% RH).

Succinic Acid: A New Platform Chemical for Biobased Polymers from Renewable Resources

“…A technical synthesis of PA 44 has not been described in the literature yet. Publications can be found concerning polyamides, either on the basis of 1,4-butanediamine (PA 4n) [55][56][57][58] or on the basis of succinic acid (PA n4) [56,[59][60][61][62]. These polyamide types show interesting and unexpected properties.…”

“…A shortchain aliphatic PA 42 manufactured by polycondensation of 1,4-butanediamine with diethyl oxalate could be interesting for use as fibers [56].…”

Polymorphism of poly(nonamethyleneoxamide) crystal

“…In the case of even polyoxamides, the crystal structures of nylon-4,2 [15], nylon-6,2 [16,17] nylon-8,2 [16], nylon-10,2 [16], and nylon-12,2 [16,18] were studied by means of wideangle X-ray diffraction (WAXD). The WAXD patterns of the crystals of these polyoxamides show two characteristic Bragg reflections at d-spacings of 4.5 and 3.7 Å, similar to the -form of even-even nylons.…”

Oxalamides as a hydrogen bonding motif in thermoplastic elastomers

“…Crystalline structures based on Xray and electron diffraction measurements are reported for nylon-6,2, nylon-9,2 and nylon-12,2 109,110,113 . Powder X-ray diffraction patterns have been published for nylon-4,2, nylon-6,2, nylon-8,2, and nylon-10,2 105,111 . For all even nylon-X,2 polymers, an extended planar zig-zag conformation was proposed with intermolecular hydrogen bonding between neighboring chains in a single direction.…”

“…The most frequent used polymerization method for the preparation of high molecular weight polyoxalamides is the reaction between an oxalate ester and a diamine 105,[109][110][111] .…”