scholarly journals Study on tri-imidazole derivatives modified with triazine-trione structure as latent curing agents for epoxy resin

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaodong Wan ◽  
Jianben Liu ◽  
Xi Chen ◽  
Jun Wang
Keyword(s):  
Glass Transition ◽  
Epoxy Resin ◽  
Storage Stability ◽  
Crosslinking Density ◽  
Exothermic Peak ◽  
List Type ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Imidazole Derivatives ◽  
Long Storage

Abstract In this paper, four novel kinds of triazine-trione based tri-imidazole derivatives (IM-TT, 2MI-TT, 2EI-TT and EMI-TT) were synthesized through the addition reaction between triglycidyl isocyanurate (TGIC) and imidazole (IM), 2-methylimidazole (2MI), 2-ethylimidazole (2EI) and 2-ethyl-4-methylimidazole (EMI), respectively. The triazine-trione based tri-imidazole derivatives were blended with epoxy resin and the reactivity, thermal latency and thermal property were investigated. The results on curing behaviors indicated that the curing exothermic peaks of the blends with triazine-trione based tri-imidazole derivatives shifted to higher temperatures compared with those with commercial imidazoles. The curing exothermic peak temperatures (Tps) of the synthesized tri-imidazole derivatives were increased by 23–32 ℃ compared with the unmodified imidazoles. In addition, Rheological behavior results indicated that the EP blends with tri-imidazole derivatives also exhibited excellent storage stability which was as long as 38 days under room temperature. Last but not the least, the EP blends with triazine-trione based tri-imidazole derivatives also exhibited high glass transition temperatures due to introducing of triazine-trione structures with high crosslinking density. The glass transition temperatures (Tgs) of the prepared thermosets ranged from 128 to 152 ℃. The triazine-trione based tri-imidazole derivatives provide a way to prepare latency epoxy resin with high high glass transition temperature and long storage stability. Article Highlights Four novel kinds of triazine-trione based tri-imidazole derivatives were synthesized. The EP cured with the tri-imidazole derivatives displayed great thermostability. The EP cured with the tri-imidazole derivatives exhibited long storage stability.

Study on the Copolymer Properties of Phenolic Resin-Epoxy Resin

2012 ◽  
Vol 531-532 ◽  
pp. 73-78 ◽  
Author(s):  
Xiao Yan Zhang
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Epoxy Resin ◽  
Phenolic Resin ◽  
Curing Agent ◽  
Transition Temperatures ◽  
Service Temperature ◽  
Glass Transition Temperatures ◽  
Reactive Process ◽  
Ft Ir

The properties of phenolic-epoxy copolymer were studied in this paper. DSC was used to detect the possibility of copolymerization between phenolic resin and epoxy resin. FT-IR monitored the reactive process of mixed resin in various temperature stages. DMA revealed that the copolymer possessed high moduli and glass transition temperatures. The result showed that phenolic-epoxy copolymer can react in appropriate proportion. It is better for the copolymer system to avoid rich epoxy without curing agent. The properties of the copolymer could be increased when sacrificed some excellent properties of phenolic and epoxy. The copolymer 70% phenolic & 30% epoxy and 60% phenolic & 40% epoxy posses higher service temperature, lower volumetric shrinkage and excellent mechanical properties.

Crossover of the Curing Mechanisms and Double Glass Transition Temperatures of Tetrabromo-Bisphenol-a Epoxy Resin with 4,4-Diaminodiphenylsulfone

2011 ◽  
Vol 233-235 ◽  
pp. 2029-2033 ◽  
Author(s):  
Xing Fang Yao ◽  
Shi Feng Zhang
Keyword(s):  
Glass Transition ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Transition Temperatures ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Autocatalytic Model ◽  
Maximum Reaction ◽  
Higher Temperature ◽  
Lower Temperature

The curing process of tetrabromo-bisphenol-A epoxy resin (TBBPAER) with 4,4´-diaminodiphenylsulfone (DDS) was investigated by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and torsional braid analysis (TBA) methods. FTIR results indicated that the maximum reaction velocity was observed at initial stages at higher temperature, but it was occurred at conversion =10 - 40 % at lower temperature. It showed that there is the crossover from the autocatalytic model to the nth-order mechanism when the temperature was increased. While the double glass transition temperatures occuring in the system, according to the microstructure of the reactant, a theoretical and reasonable explanation may arise from this article.

Time-temperature dependence of fracture toughness for bisphenol a epoxy resin

2002 ◽  
Vol 216 (2) ◽  
pp. 79-84 ◽  
Author(s):  
W Araki ◽  
T Adachi ◽  
M Gamou ◽  
A Yamaji
Keyword(s):  
Fracture Toughness ◽  
Glass Transition ◽  
Transition Temperature ◽  
Bisphenol A ◽  
Temperature Dependence ◽  
Epoxy Resin ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Brittle Ductile Transition ◽  
Fragility Parameter

The relationship between the curing conditions and the time-temperature dependence of fracture toughness was investigated for bisphenol A epoxy resin. The glass transition temperature and Angell's fragility parameter, which are obtained from thermoviscoelasticity measurements, were used to characterize epoxy resins cured under various conditions. Examination of the fracture toughness at various temperatures and displacement rates showed that it depends on both temperature and time, and that it follows the time-temperature equivalence principle. The time-temperature dependence of the fracture toughness was greatly affected by the fragility parameter. The fracture toughness of the resin with a smaller fragility parameter increased from lower temperatures to the brittle-ductile transition temperature than that of the resin with a larger fragility parameter when their glass transition temperatures were approximately 400 K. It was also found that the brittle-ductile transition temperature did not depend on the fragility parameter. This means that epoxy resin with a smaller fragility parameter has better fracture characteristics than epoxy resin with a larger fragility parameter if their glass transition temperatures are approximately 400 K.

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