Hyperbranched polyethers with tunable glass transition temperature: controlled synthesis and mixing rules

Abstract

Using competing reactions to achieve controllability in hyperbranched polymers and Tg mixing laws in hyperbranched blends and copolymers.

Hyperbranched polyether as an all-purpose epoxy modifier: controlled synthesis and toughening mechanisms

“…Similar to HBPEs prepared by AB 2 monomers, 14 the M W of HBPE prepared using the A 2 + B 3 approach is also insensitive to reaction time and stabilises in a short time (less than 6 h) aer monomer addition. By comparing the corresponding peaks in the 1 H-NMR spectrum of HBPE (Fig.…”

“…Detailed procedures for synthesising triphenol methane can be found elsewhere. 13,14 The obtained triphenol methane is a brickred solid with a yield of 70%.…”

“…3b), double bonds (C]C) are observed in HBPE, which is consistent with our previous results using the AB 2 approach. 14 The fast stabilisation is attributed to the competition between elimination and substitution reactions. 16 In addition, no -Br groups were found in the NMR spectrum (Fig.…”

“…Although "in situ" toughening mechanisms has been proposed to explain the improved toughness in non-phaseseparated epoxies, detailed and convincing toughening mechanisms are still lacking. In order to address these issues, our paper covers three parts: rst, by taking advantage of competing side reactions, 14 the controlled synthesis of a hyperbranched polyether is demonstrated using a one-pot A 2 + B 3 approach; second, when added as a toughener for epoxy, simultaneous improvements in T g , toughness, and strength are demonstrated, and the effects of loading amount are investigated; and third, explanations for the simultaneous improvements are provided. In particular, detailed explanations including new toughening mechanisms in the non-phase-separated epoxy network are offered for the rst time.…”

New Monomer Based on Eugenol Methacrylate, Synthesis, Polymerization and Copolymerization with Methyl Methacrylate–Characterization and Thermal Properties

“…The Fox equation [40] was also used to predict the glass transition temperature of a copolymer. According to different authors [41][42][43][44], statistical or random copolymers are characterized by a good correlation between the experimental values of T g and those calculated from the Fox equation. On the other hand, the values of T g for alternative copolymers deviate from those calculated.…”