Manipulation of the molecular weight and branching structure of hyperbranched poly(arylene ether phosphine oxide)s prepared via an A₂ + B₃ approach

Abstract

A series of hyperbranched poly(arylene ether phosphine oxide)s (HB PAEPOs) were prepared via an A 2 ϩ B 3 polymerization scheme with tris(4-fluorophenyl)phosphine oxide as B 3 , and a variety of bisphenols as A 2 . The effects of the reactivity of the A 2 monomer, the A:B ratio, the addition mode, the solvent, and the concentration on the final molecular weight, polydispersity index (PDI), and degree of branching (DB) were studied. Soluble HB PAEPOs with weight-average molecular weights of up to 299,000 Da were achieved. Reactions in which the A 2 component was added slowly resulted in lower DBs (0.2-0.5), whereas the slow addition of the B 3 component provided samples with DBs of approximately 0.75. Reactions performed under highdilution conditions afforded completely soluble materials with weight-average molecular weights of 9000 -12,100 Da and PDI values as low as 2.20. The molecular weights achieved under high-dilution conditions were independent of the mode of monomer addition.

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

“…[49][50][51] Fossum and Czupik used 31 P NMR spectroscopy to confirm that significant cyclization reactions led to high molar mass hyperbranched poly(arylene ether)s in the polymerization of low molar mass A 2 and B 3 monomers. [67] Thus, hyperbranched products derived from A 2 and B 3 monomers will contain one or more cyclic structures in each hyperbranched molecule if significant cyclization reactions occur during the polymerization. However, it remains difficult to precisely characterize the average number of cyclic structures in hyperbranched molecules.…”

“…The TFPPO B 3 monomer provided an important analytical advantage as the final dendritic, linear, and terminal unit in the branched polymer products exhibited significantly different chemical shifts in the 31 P NMR spectra ( Figure 4). [56,67] This desirable spectroscopic tag allowed an investigation of the branched structures as a function of B 3 conversion. Moreover, the B 3 monomer, terminal units, and linear units also exhibited different chemical shifts in the 19 F NMR spectrum ( Figure 5), which provided a complementary method to confirm the 31 P NMR results.…”

Multicyclic Poly(ether ketone)s by Polycondensation of 1,3,5‐Tris(4‐fluorobenzoyl)benzene with Various Diphenols

“…With such stoichiometry, conversions near 100% can be achieved without gelation, and the formation of hyperbranched polymers has been postulated and reported by several research groups. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] However, the influence of cyclization reactions has rarely been discussed [6,20] and the synthesis of soluble multicyclic polymers has not been elaborated.…”

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.…”