Premium
Novel imidazole derivatives with recoverable activity as latent curing agents for epoxy
Author(s) -
Shi Kunxiang,
Shen Yucai,
Yang Yunxu,
Wang Tingwei
Publication year - 2021
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49730
Subject(s) - imidazole , epoxy , curing (chemistry) , differential scanning calorimetry , polyethylene glycol , materials science , polymer chemistry , tertiary amine , amine gas treating , organic chemistry , chemistry , composite material , physics , thermodynamics
Abstract A series of latent curing agents were developed by replacing the hydrogen atom on secondary amine in imidazole with methoxy polyethylene glycol maleate diesters via Michael addition reaction. Methoxy polyethylene glycol maleate diesters with different molecular weight also restrained the reactivity of tertiary amine in imidazole ring. The curing properties and pot‐life of the modified imidazole/epoxy systems were measured by differential scanning calorimeter and rotational rheometer. The modified imidazole/epoxy system could be cured quickly at 175°C. The modified imidazole shows good latency. After stored for more than 1 month, viscosity of modified imidazole/epoxy system remains unchanged. The longer chain polyether had the better thermal latency these curing agents had. Compared with unmodified imidazole, the novel latent curing agents led to better impact strength for cured epoxy. However, the compatibility between epoxy and latent curing agent will get worse if the molecular weight of polyether unite is over 750.