Synthesis and Characterization of Hyperbranched Poly(arylene ether)s from a New Activated Trifluoro B₃ Monomer Adopting an A₂ + B₃ Approach

Abstract

A new trifluoromethyl‐activated trifluoro monomer was successfully prepared by Pd‐initiated coupling of 1,3,5‐tribromobenzene with 4‐fluoro‐3‐trifluoromethylphenylboronic acid. 1,3,5‐Tris(4‐fluoro‐3‐trifluoromethylphenyl)benzene (B3) leads to several hyperbranched poly(arylene ether)s when reacted with three different bisphenols (A2) in different molar ratios. The 1.5:1 molar product of A2/B3 showed very high molecular weight without significant gelation. The products have been well characterized by GPC, DSC, TGA, FTIR, and NMR techniques. The 19F NMR signals were used to calculate the degree of branching. The 1.5:1 molar products have excellent thermal stability and higher glass transition temperatures than their linear analogs.magnified image

Aromatic Hyperbranched Polymers: Synthesis and Application

“…The AB 2 monomers self-condensed to form different hb-PAEKs and the T g was 175, 197, or 215 C, depending on whether the repeat unit structure contained biphenyl, terphenyl, or quadriphenyl units in the polymer backbone. C, which was higher than the previously reported T g by Miller et al (140)(141)(142)(143) C) [63]. The hb homopolymer showed a bimodal molecular weight distribution that was also observed for other related linear hb systems.…”

“…Banerjee et al synthesized a new trifluoromethyl-activated trifluoro monomer by Pd-initiated coupling of 1,3,5-tribromobenzene with 4-fluoro-3-trifluoromethylphenylboronic acid to afford 1,3,5-tris(4-fluoro-3-trifluoromethylphenyl)benzene as B 3 monomer (1-45, Scheme 14) [143]. The B 3 monomer was reacted with three different bisphenols, namely 4,4 0 -isopropylidenediphenol (BPA), 4,4-0 -(hexafluoroisopropylidene) diphenol (6F-BPA), and 4,4 0 -(9-fluorenylidene) diphenol (C-BPA), as A 2 monomers in different molar ratios (A 2 :B 3 ¼ 1:1, 1.5:1, or 2:1) leading to several fluorinated hb poly(arylene ether)s (F-hb-PAEs).…”

“…The metallophthalocyanine-containing hb-PIs also showed good solubility in polar aprotic solvents and CHCl 3 and their M n varied from 25,300 to 31,800 Da. The T g values of these polymers were in the range of [217][218][219][220][221][222][223][224][225] C and the T d,5% varied from 440 to 487 C. Banerjee et al [143] synthesized a triamine monomer B 3 (1-18, Scheme 9a) with the aim of preparing fluorinated hb-PIs by the A 2 + B 3 approach using commercially available dianhydrides as A 2 monomers. However, during solution imidization of the amide acids that formed by the reaction of the dianhydrides and B 3 monomer, an appreciable amount of gelation was observed for all the molar ratios, except when 6FDA was used as dianhydride for reaction molar ratio of 1:1 and the solution concentration was maintained at 2.7 wt%.…”

“…The lowest dielectric constant value attained was 2.54 in the hb-PI/POSS nanocomposite because of the large free volume and loose polyimide structures. The fluorinated hb poly(aryl ether)s (F-hb-PAEs) synthesized [143,197] could be used for dielectric coatings, which require crosslinked films on a substrate after high-temperature baking. The dielectric constant values (ε ¼ 2.67 AE 0.2) obtained for the analogous linear poly(aryl ether)s [323] support the fact that these F-hbPAEs exhibit even lower dielectric constants due to the increased free volume arising from the highly branched architecture and to the -CF 3 pendant groups on these polymers.…”

Self-healing hyperbranched poly(aroyltriazole)s

“…No hyperbranched PATA ( hb -PATA), however, has been prepared by this powerful polymerization technique. The hb -PATAs are expected to show unique properties due to their topological global structures48, and the remaining tremendous reactive azide and aroylacetylene groups on the periphery makes hb -PATAs promising candidates to be developed into simple self-healing systems49.…”