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Preparation and purification of bisacid A2 (2,2‐diphenylolpropane 4,4‐dioxyacetic acid). II
Author(s) -
Lenk R. S.
Publication year - 1971
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1971.070150719
Subject(s) - alkyd , polyester , acetic acid , yield (engineering) , melting point , condensation polymer , recrystallization (geology) , ether , polyamide , organic chemistry , materials science , chemistry , chromatography , polymer , composite material , coating , paleontology , biology
Abstract In an earlier communication 1 the preparation of Bisacid A2 was described. This paper describes the attempts at spotting impurities in the products so obtained by subjecting them to thin‐layer chromatography. No traces of impurities could be detected since no separation whatever was observed. Infrared spectra of pure Bisacid A2 were found to be identical with the spectrum of Nanu and Boboescu. 2 It was also seen that the product obtained by the standard preparation in 70–73% yield with a minimum melting point of 173°C could not be demonstrably improved by esterification and rehydrolysis. Second crops from first mother liquors from the aqueous acetic acid recrystallization of the crude precipitated product of the condensation reaction (as well as ether extracts from these mother liquors) showed that both contained material with phenolic OH groups. These are the inpurities in the crude product which must be completely removed during purification if the final material is to be used for the synthesis of unsaturated polyester resins for ultimate use as crosslinked reinforced plastics, as alkyd varnish bases, or as fiber‐forming saturated polyesters and polyamides. The need for adhering to the standard synthetic procedure was confirmed, in particular the need for multistage condensation, giving an effective yield of 70–73% of pure material