A preliminary study on polyhydrazides incorporating furan moieties

Polyamide-imides bearing furan moieties. 1. Solution polycondensation of aromatic dianhydrydes with 2-furoic acid dihydrazides

“…The 2-furoic acid dihydrazides 1a-1f (Scheme 2) were prepared as described previously [13] by treating with hydrazine hydrate (Aldrich) the corresponding diesters obtained in turn by the condensation of ethyl 2-furoate with the corresponding aldehyde or ketone, as reported in detail elsewhere [14]. 1,2,4,5-Benzene-tetracarboxylic anhydride 2 and 3,3 0 ,4,4 0 -benzophenone-tetracarboxylic dianhydride 3 (both Aldrich) were purified by refluxing for 2 h in acetic anhydride and subsequently crystallising them from the same medium.…”

“…CM 3 and CM 4 were obtained by imidisation of CM 1 and CM 2 , respectively using thermal and chemical cyclodehydration. The complete thermal imidisation was attained after 12 h, whereas the chemical route only needed 1 h. It was established that the cyclodehydration reaction involving NH and COOH groups gave selectively imide functions, without formation of any detectable 1,3,4-oxadiazole rings by cyclodehydration of the OaC-NH-NH-CaO moieties [13].…”

“…Given the extensive experience of our laboratories in the field of furan-based polymers [10][11][12][13], we decided to study the synthesis of a novel class of polyamide-imides incorporating 2,5-substituted furan moieties (1378) in their backbone, which would be more flexible than their fully 1,4-aromatic counterparts (1808), by breaking the chain linearity and reduce the polymer packing density, as in the case of 1,3-aromatic monomer units [1,2]. Thus, the presence of both furan and amide groups in the final macromolecules was thought to lead to improved solubility and lower softening temperatures, while maintaining good thermal and mechanical properties.…”

“…FTIR data related to PAI 1-10 NMR data related to polyamide-imides PAI 1-12 (DMSO-d 6 /TMS)13 C NMR data related to PHA 1 and PAI 1 (DMSO/TMS)…”

Synthesis of amines of the di-and trifurylmethane series

“…Difurylmethanes occupy a significant place among furan derivatives. Difurylmethane structures have attracted the attention of investigators engaged in the chemistry of polymeric compounds since they are readily obtainable replacements for the diphenylmethanes employed in the synthesis of polymers [1][2][3][4]. Diamines of the difurylmethane series have found use in the production of epoxide resins [5], while the difurfuryl diisocyanates synthesized from them are used in the production of polyurethane systems [6][7][8].…”