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 ◽  
Bisphenol A ◽  
Temperature Dependence ◽  
Epoxy Resin

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.

Time-temperature dependency of mode II fracture toughness for bisphenol A type epoxy resin

2005 ◽  
Vol 96 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Wakako Araki ◽  
Daisuke Asahi ◽  
Tadaharu Adachi ◽  
Akihiko Yamaji
Keyword(s):  
Fracture Toughness ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Mode Ii ◽  
Temperature Dependency ◽  
Mode Ii Fracture ◽  
Mode Ii Fracture Toughness

K-0843 Curing State Effect on Time-Temperature Dependence of Fracture Toughness of Epoxy Resin

2001 ◽  
Vol I.01.1 (0) ◽  
pp. 465-466
Author(s):  
Wakako ARAKI ◽  
Tadaharu ADACHI ◽  
Masahiro GAMOU ◽  
Akihiko YAMAJI
Keyword(s):  
Fracture Toughness ◽  
Temperature Dependence ◽  
Epoxy Resin ◽  
State Effect

Development and Characterisation of a Oxazolidone-Isocyanurate-Urethane Modified Diglycidyl Ether of Bisphenol A Epoxy Resin

1999 ◽  
Author(s):  
K. S. Chian ◽  
S. Yi
Keyword(s):  
Thermal Stability ◽  
Fracture Toughness ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Diglycidyl Ether ◽  
Thermomechanical Behaviour ◽  
Structural Applications ◽  
Chemical Groups ◽  
Mechanical Strengths ◽  
Modified Epoxy

Abstract Epoxy resins are very versatile polymers generally known not only for their adhesive and mechanical strengths but also their inherent thermo-oxidative stability. These properties have been widely exploited in many applications ranging from composites used aerospace components to electronics packaging. However neat epoxy materials suffer from relatively poor strain bearing ability and attempts to improve this brittle behaviour have been an area of many research interests. Toughening of epoxy using elastomers is not new and this is reflected in numerous publications and some have been successfully commercialised. This paper presents a relatively new method of incorporating a rubber modifier into Diglycidyl ether of Bisphenol A (DEGBA) epoxy resin via the formation of an isocyanurate-oxazolidone-urethane structure. The synthesis involves several simultaneous reactions involving the following reactions: (a) epoxide and the isocyanate to form the oxazolidone, (b) trimerisation of the isocyanate to form isocyanurate and (c) isocyanate with polyols to form polyurethane. The synthesis and characterisation of the modified DEGBA resin will be presented. In addition, the effects of rubber content on the thermomechanical behaviour of the cured resin will also be discussed. In summary, it was found that the introduction of the isocyanurate-oxazolidone-urethane chemical groups into the epoxy molecular chain not only enhances the fracture toughness of the final resin but also improves on the thermal stability. This rubber-modified epoxy system shows excellent promise for adhesive and structural applications where thermal stability and fracture toughness are pre-requisites.

Fracture toughness of bisphenol A-type epoxy resin

2002 ◽  
Vol 86 (9) ◽  
pp. 2266-2271 ◽  
Author(s):  
Wakako Araki ◽  
Tadaharu Adachi ◽  
Akihiko Yamaji ◽  
Masahiro Gamou
Keyword(s):  
Fracture Toughness ◽  
Bisphenol A ◽  
Epoxy Resin

scholarly journals Studies on the Modification of Commercial Bisphenol-A-Based Epoxy Resin Using Different Multifunctional Epoxy Systems

2021 ◽  
Vol 2 (2) ◽  
pp. 419-430
Author(s):  
Ankur Bajpai ◽  
James R. Davidson ◽  
Colin Robert
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Tensile Fracture ◽  
Chemical Structures ◽  
Amino Phenol ◽  
Epoxy Systems

The tensile fracture mechanics and thermo-mechanical properties of mixtures composed of two kinds of epoxy resins of different chemical structures and functional groups were studied. The base resin was a bi-functional epoxy resin based on diglycidyl ether of bisphenol-A (DGEBA) and the other resins were (a) distilled triglycidylether of meta-amino phenol (b) 1, 6–naphthalene di epoxy and (c) fluorene di epoxy. This research shows that a small number of multifunctional epoxy systems, both di- and tri-functional, can significantly increase tensile strength (14%) over neat DGEBA while having no negative impact on other mechanical properties including glass transition temperature and elastic modulus. In fact, when compared to unmodified DGEBA, the tri-functional epoxy shows a slight increase (5%) in glass transition temperature at 10 wt.% concentration. The enhanced crosslinking of DGEBA (90 wt.%)/distilled triglycidylether of meta-amino phenol (10 wt.%) blends may be the possible reason for the improved glass transition. Finally, the influence of strain rate, temperature and moisture were investigated for both the neat DGEBA and the best performing modified system. The neat DGEBA was steadily outperformed by its modified counterpart in every condition.

scholarly journals Effect of rice husk (treated/untreated) and rice husk ash on fracture toughness of epoxy bio-composite

2020 ◽  
Vol 29 (1) ◽  
pp. 177-185
Author(s):  
Neeraj Bisht ◽  
Prakash Chandra Gope
Keyword(s):  
Fracture Toughness ◽  
Epoxy Resin ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Matrix Material ◽  
Secondary Reinforcement ◽  
Filler Loading ◽  
Particle Reinforcement ◽  
Pure Epoxy ◽  
Fibre Treatment

AbstractPresent work studies the effect of particle reinforcement on fracture toughness of bio-composites. The filler used has been taken as rice husk. Epoxy resin has been taken as matrix material. Composites with varying filler loading of 10, 20, 30 and 40 wt.% were fabricated. The fracture toughness was seen to be increasing with increase in filler loading. However beyond 20% there was a decrease in fracture toughness with increase in filler loading. The effect of fibre treatment on toughness was also observed. Rice husk fibres pre-treated with NaOH were used. It was observed that fracture toughness further improved due to treatment. The increase in fracture toughness was significant. Fracture toughness increased from 1.072 to 2.7465 MPa√mm for 20% reinforcement and after treatment it increased to 2.876 MPa√mm. It was observed that concentration of treatment media also affects the fracture toughness. Further the effect of hybridization was observed by addition of rice husk ash as a secondary reinforcement. The fracture toughness of the resulting composites was remarkably higher than that of pure epoxy.

scholarly journals Choosing the Right Lignin to Fully Replace Bisphenol A in Epoxy Resin Formulation

ChemSusChem ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1184-1195
Author(s):  
Saeid Nikafshar ◽  
Jiarun Wang ◽  
Kevin Dunne ◽  
Prakit Sangthonganotai ◽  
Mojgan Nejad
Keyword(s):  
Bisphenol A ◽  
Epoxy Resin ◽  
Resin Formulation ◽  
The Right
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