Curing behavior and thermal properties of trifunctional epoxy resin cured by 4,4′-diaminodiphenylmethane

2009 ◽  
Vol 114 (4) ◽  
pp. 1976-1983 ◽  
Author(s):  
Cheng Jue ◽  
Li Juan ◽  
Yang Wantai
Keyword(s):  
Thermal Properties ◽  
Epoxy Resin ◽  
Curing Behavior

scholarly journals Synthesis, Thermal Properties and Curing Kinetics of Hyperbranched BPA/PEG Epoxy Resin

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1545 ◽  
Author(s):  
Tossapol Boonlert-uthai ◽  
Chavakorn Samthong ◽  
Anongnat Somwangthanaroj
Keyword(s):  
Activation Energy ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Epoxy Group ◽  
Dendritic Structure ◽  
Curing Kinetics ◽  
Degree Of Branching ◽  
Curing Behavior ◽  
Branching Point ◽  
High Degree

The hyperbranched epoxy resins (HBE) composed of bisphenol A (BPA) and polyethylene glycol (PEG) as reactants and pentaerythritol as branching point were successfully synthesized via A2 + B4 polycondensation reaction at various BPA/PEG ratios. The 13C NMR spectra revealed that the synthesized HBE mainly had a dendritic structure as confirmed by the high degree of branching (DB). The addition of PEG in the resin enhanced degree of branching (DB) (from 0.82 to 0.90), epoxy equivalent weight (EEW) (from 697 g eq−1 to 468 g eq−1) as well as curing reaction. Adding 5–10 wt.% PEG in the resin decreased the onset and peak curing temperatures and glass transition temperature; however, adding 15 wt.% PEG in the resin have increased these thermal properties due to the lowest EEW. The curing kinetics were evaluated by fitting the experimental data of the curing behavior of all resins with the Šesták–Berggren equation. The activation energy increased with the increase of PEG in the resins due to HBE’s steric hindrance, whereas the activation energy of HBE15P decreased due to a large amount of equivalent active epoxy group per mass sample. The curing behavior and thermal properties of obtained hyperbranched BPA/PEG epoxy resin would be suitable for using in electronics application.

Curing behavior and thermal properties of multifunctional epoxy resin with methylhexahydrophthalic anhydride

2006 ◽  
Vol 103 (3) ◽  
pp. 2041-2048 ◽  
Author(s):  
Yanfang Liu ◽  
Zhongjie Du ◽  
Chen Zhang ◽  
Congju Li ◽  
Hangquan Li
Keyword(s):  
Thermal Properties ◽  
Epoxy Resin ◽  
Curing Behavior ◽  
Multifunctional Epoxy Resin

scholarly journals Curing Behavior, Rheological, and Thermal Properties of DGEBA Modified with Synthesized BPA/PEG Hyperbranched Epoxy after Their Photo-Initiated Cationic Polymerization

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2240
Author(s):  
Tossapol Boonlert-uthai ◽  
Kentaro Taki ◽  
Anongnat Somwangthanaroj
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Cationic Polymerization ◽  
Gelation Time ◽  
Radius Of Gyration ◽  
Curing Behavior

This paper investigates the photo-initiated cationic polymerization of diglycidyl ether of bisphenol A (DGEBA) modified with bisphenol A (BPA)/polyethylene glycol (PEG) hyperbranched epoxy resin. The relationship between curing behavior, rheological, and thermal properties of the modified DGEBA is investigated using photo-differential scanning calorimetry (DSC) and photo-rheometer techniques. It is seen that the addition of the hyperbranched epoxy resin can increase UV conversion (αUV) and reduce gelation time (tgel). After photo-initiation polymerization (dark reaction) occurred, a second exothermic peak in the DSC thermogram takes place: namely, the occurrence of curing reaction owing to the activated monomer (AM) mechanism. Consequently, the glass transition temperature decreased, and at the same time, UV intensity increased which was due to the molecular weight between crosslinking points (Mc). Furthermore, the radius of gyration (Rg) of the network segment is determined via small-angle X-ray scattering (SAXS). It is noted that the higher the Mc, the larger the radius of gyration proves to be, resulting in low glass transition temperature.

scholarly journals Reaction Mechanism and Mechanical Property Improvement of Poly(Lactic Acid) Reactive Blending with Epoxy Resin

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2429
Author(s):  
Krittameth Kiatiporntipthak ◽  
Nanthicha Thajai ◽  
Thidarat Kanthiya ◽  
Pornchai Rachtanapun ◽  
Noppol Leksawasdi ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Epoxy Resin ◽  
Softening Temperature ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Nanoparticle Dispersion ◽  
Reactive Blending ◽  
Partial Miscibility ◽  
Epoxy Blends ◽  
Epoxy Content

Polylactic acid (PLA) was melt-blended with epoxy resin to study the effects of the reaction on the mechanical and thermal properties of the PLA. The addition of 0.5% (wt/wt) epoxy to PLA increased the maximum tensile strength of PLA (57.5 MPa) to 67 MPa, whereas the 20% epoxy improved the elongation at break to 12%, due to crosslinking caused by the epoxy reaction. The morphology of the PLA/epoxy blends showed epoxy nanoparticle dispersion in the PLA matrix that presented a smooth fracture surface with a high epoxy content. The glass transition temperature of PLA decreased with an increasing epoxy content owing to the partial miscibility between PLA and the epoxy resin. The Vicat softening temperature of the PLA was 59 °C and increased to 64.6 °C for 0.5% epoxy. NMR confirmed the reaction between the -COOH groups of PLA and the epoxy groups of the epoxy resin. This reaction, and partial miscibility of the PLA/epoxy blend, improved the interfacial crosslinking, morphology, thermal properties, and mechanical properties of the blends.

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