Multicyclic Poly(ether sulfone)s Derived from Tris(4‐hydroxyphenyl)ethane

Abstract

Polycondensations of 4,4′‐difluorodiphenylsulfone with tris(4‐hydroxy phenyl)ethane were performed in DMSO with variation of feed ratio and concentration. For feed ratios of 1.0:1.3–1.0:1.5, soluble multicyclic poly(ether sulfone)s were obtained when the monomer concentration was below 0.05 M. The conversions were never complete under standard conditions, and doubling the reaction time yielded perfect multicyclic products free of endgroups; however, a small fraction of the product was crosslinked under these conditions. Quite similar results were obtained with 4,4′‐dichlorodiphenylsulfone at higher temperatures. When K2CO3 was replaced by tertiary amines, conversions and molecular weights were lower. The multicyclic poly(ether sulfone)s were characterized by MALDI‐TOF mass spectrometry, SEC, and DSC measurements. Broad molecular weight distributions with polydispersities in the range of 2.4–3.9 were found, and, surprisingly, two glass transitions were detectable in the DSC heating curves.magnified image

Non‐Stoichiometric Polycondensations and the Synthesis of High Molar Mass Polycondensates

“…Analogous polycondensations of THPE resulted in crosslinking at a feed ratio of 1.2/1.0 91. Yet, when the IMC was lowered to 0.05 mol L −1 all reaction products were soluble regardless of the stoichiometry,92 and perfect multicycles were obtained from the equifunctional feed ratio.…”

“…Several attempts to prepare and characterize soluble polymers according to scenarios D and F were reported by Kricheldorf and co‐workers 90–100. Prior to a comment on individual reactions, it should be mentioned that special sum formulas and structural formulas were developed for a precise and short labelling of the cyclic and multicyclic polymers resulting from “ a 2 + b n ” polycondensations with [a 2 ]/[b n ] ratios > 1.0/1.0.…”

Cyclic and Multicyclic Polymers by Three-Dimensional Polycondensation

“…Even at this low feed ratio, the reaction product almost completely consisted of cyclic and multicyclic polyethers. When DFDPS was polycondensed with free THPL at a monomer concentration of 0.05 mol/L, all reaction products were soluble regardless of the feed ratio, and at feed ratios around 1.5:1.0, the perfect multicycles were the predominant reaction products …”

“…When DFDPS was polycondensed with free THPL at a monomer concentration of 0.05 mol/L, all reaction products were soluble regardless of the feed ratio, and at feed ratios around 1.5:1.0, the perfect multicycles were the predominant reaction products. 52 Particularly interesting were polycondensations of silylated THPE with 2,6-and 2,4-difluorobenzonitrile (Scheme 10). 53 At a THPE concentration of 0.12 mol/L, the 2,6 isomer yielded gels at a feed ratios >1.1:1.0.…”

Mass Spectrometry of Synthetic Polymers

“…The same MS method was used to investigate the effect of long time aging on the chain end of poly( p -methoxystyrene) . Furthermore, the characterization of poly(ether imide)s , , poly(amidoamines), poly(ester amide)s , poly(epichlohydrin) , telechelic poly( N -isopropylacrylamides) , cyclic poly(lactides) , enantiomeric poly(α-methyl-α-ethyl-β-propiolactones) , and multicyclic poly(ether sulfone)s by MALDI-TOF MS was reported. Liu and Mishra described the atom-transfer radical polymerization of menthyl acrylate .…”