Highly Branched Poly(arylene ether)s via Oligomeric A₂ + B₃ Strategies

Abstract

Summary: Branched poly(arylene ether)s were prepared in an oligomeric A2 + B3 polymerization of phenol endcapped telechelic poly(arylene ether sulfone) oligomers as A2 and TFPPO as trifunctional monomer B3. The molar mass of the A2 oligomer significantly influenced the onset of gelation and the DB. A high level of cyclization during polymerization of low molar mass A2 oligomers (U3 = 660 and U6 = 1 200 g · mol−1) led to a high conversion of functional groups in the absence of gelation, and the level of cyclization reactions in the polymerization decreased as the molar mass of the A2 oligomer was increased. The pronounced steric effect in the polymerization of higher molar mass A2 oligomers (U8 = 1 800 and U16 = 3 400 g · mol−1) resulted in low reactivity of the third aryl fluoride in the B3 monomer. As a result, only slightly branched (U8 = 1 800 g · mol−1) or nearly linear (U16 = 3 400 g · mol−1) high molar mass products were obtained with higher molar mass A2 oligomers. The branched polymers exhibited lower Mark‐Houwink exponents and [η] relative to linear analogs, and differences between the branched polymers and linear analogs were less significant as the molar mass of the A2 oligomers was increased due to a decrease in the overall DB. magnified image

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

“…[31,32] However, very few report on the synthesis of hyperbranched poly(arylene ether)s by adapting A 2 þ B 3 exist. [33] In this work, we describe the synthesis and characterization of a new trifluoromethyl-activated trifluoro monomer; 1,3,5-tris(4-fluoro-3-trifluoromethylphenyl)benzene (B 3 ) and several hyperbranched poly(arylene ether)s by the reaction of this B 3 monomer with different commercial diphenols. Some findings on hyperbranched poly(ether imide)s based on a new triamine (B' 3 ) monomer are also reported.…”

Aromatic Hyperbranched Polymers: Synthesis and Application

“…The self-condensation of AB 2 monomer at room temperature, carried out at a dilute concentration of 0.06-0.16, led to low molecular weight oligomers of~11,100 Da and, hence, polymerization was investigated at higher solution concentration and at a temperature of 50 C. Increasing the solution concentration from 0.06 to 0.32 g/ mL showed a limited increase in molecular weight up to 25,500 Da; however, increasing the temperature to 50 C at a dilute concentration of 0.08 g/mL resulted in a marked increase in molecular weight to 173,000 Da. The T g values of the hb-PIs were found to be in the range of [155][156][157][158][159][160][161] C and showed an increasing trend with increase in molecular weight. The T d,5% values for the hb-PIs were 445-460 C, indicating high thermal stability.…”

“…Lin et al [161] reported the preparation of hb polymers, with moderately branched, slightly branched, and linear topologies by phenol end-capped telechelic poly(arylene ether sulfone) oligomers as A 2 and tris(4-fluorophenyl) phosphine oxide as trifunctional monomer B 3 . When bisphenol A and low molar mass oligomers were used as A 2 , pronounced cyclic reactions led to branched products without gelation.…”

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

“…condensation [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] with the intention to prepare (hyper)-branched polymers free of cycles.…”