Polymerization of A₂ with B₃ Monomers:  A Facile Approach to Hyperbranched Poly(aryl ester)s

Abstract

Hyperbranched polymers have received significant attention due to their unique combination of low viscosity, excellent solubility, and facile synthesis. This paper describes an efficient approach to hyperbranched poly(aryl ester)s via the polycondensation of A2 and B3 monomers. A dilute bisphenol A (A2) solution was added slowly to a dilute 1,3,5-benzenetricarbonyl trichloride (B3) solution at 25 °C to prepare hyperbranched poly(aryl ester)s in the absence of gelation. The molar ratio of A2:B3 was maintained at 1:1, and the maximum final monomer concentration was ∼0.08 M. 1 H NMR spectroscopy and derivitization of terminal groups indicated that the phenol functionalities were quantitatively consumed during the polycondensation. Two model compounds were synthesized to identify 1 H NMR resonances for linear, dendritic, and terminal units, and the final degree of branching was determined to be ∼50%. Moreover, the hyperbranched polymers exhibited lower glass transition temperatures relative to their linear analogues.

Liquid crystalline photoactive hyperbranched and linear benzylidene polyester with terminal epoxy and pendant hydroxyl groups

“…The integral values of dendritic, linear and terminal unit proton resonances of benzene tricarboxylic acid (around d 8.74-8.68 ppm) were used for the estimation. 9,10,25,26 The DB value is found to be 0.52, which agree well with general scale for the hyperbranched polymers made by one-pot procedure. 53 …”

“…7 Limited availability of AB n monomers increases the use of readily available A 2 þ B 3 monomers for the synthesis of HBP. 8,[9][10][11] After preliminary work by Kim 12 on hyperbranched liquid crystalline polymers, (HBLCPs), synthesized by the AB n approach, the revolutionary work in this field was carried out by Percec et al, [13][14][15][16][17][18] Shibaev et al, 19 and others [20][21][22][23] have reported on photo-addressable dendritic polymers (PADLCPs) containing both mesogenic and photochromic groups. PADLCPs have shown enhanced physicochemical properties and photo and thermally induced physical changes as compared with linear polymers.…”

Degree of Branching in Hyperbranched Poly(glycerol-co-diacid)s Synthesized in Toluene

“…glycerol, in the presence of lipase and chemical catalysts to form hyperbranched polymers [1][2][3][4][5][6][7]. Understanding the relationship between D.B% and the physical and chemical properties of hyperbranched polymers is necessary to identify potential applications.…”

Facile one-spot synthesis of highly branched polycaprolactone

“…[1][2] The former approach has mainly been achieved by the polycondensation of multifunctional monomers such as AB 2 , AB 2 + B y 24 and A 2 + B y type structures. 25 Meanwhile, the latter method has been based on a specific method called Ring-opening Multibranching Polymerisation (ROMBP) of latent AB 2 monomer, i.e. the ring-opening polymerisation of cyclic monomers in which the initiator is attached to the monomer ring.…”