Curing Behavior for Microencapsulated Curing Agents on Epoxy Resin Systems

2015 ◽  
Vol 737 ◽  
pp. 150-153
Author(s):  
Xi Wang
Keyword(s):  
Epoxy Resin ◽  
Room Temperature ◽  
Reaction Order ◽  
Diglycidyl Ether ◽  
Initiation Mechanism ◽  
Step Initiation ◽  
Two Samples ◽  
Curing Kinetic ◽  
Evaporation Technique ◽  
Curing Agents

Microcapsules containing a curing agent, 2-phenyl imidazole (2PZ), for a diglycidyl ether of bisphenol A (DGEBA) epoxy resin were prepared by a solid-in-oil-inwater emulsion solvent evaporation technique with poly (methyl methacrylate) (PMMA) as a polymeric wall. The former could take more than 3 months at room temperature, whereas the latter was cured after only a week. The values of the reaction order (a curing kinetic parameter) for DGEBA/2PZ and DGEBA/2PZ–PMMA microcapsules were quite close, and this showed that the curing reactions of the two samples proceeded conformably. The curing mechanism was investigated, and a two-step initiation mechanism was considered: the first was assigned to adduct formation, whereas the second was due to alkoxide-initiated polymerization.

Investigating the relationship between tack and degree of conversion in DGEBA-based epoxy resin cured with dicyandiamide and diuron

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Kuliaei ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Epoxy Resin ◽  
Reaction Order ◽  
Theoretical Data ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Degree Of Conversion ◽  
Ozawa Method ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Kinetics Of

Abstract The purpose behind this research was to determine the optimum formulation and investigate the cure kinetics of a diglycidyl ether of bisphenol-A (DGEBA)-based epoxy resin cured by dicyandiamide and diuron for use in prepregs. First, all formulations were examined by the tensile test, and then, the specimens with higher mechanical properties were further investigated by viscometry and tack tests. The cure kinetics of the best formulation (based on tack test) in nonisothermal mode was investigated using differential scanning calorimetry at different heating rates. Kissinger and Ozawa method was used for determining the kinetic parameters of the curing process. The activation energy obtained by this method was 71.43 kJ/mol. The heating rate had no significant effect on the reaction order and the total reaction order was approximately constant ( m + n ≅ 2.1 $m+n\cong 2.1$ ). By comparing the experimental data and the theoretical data obtained by Kissinger and Ozawa method, a good agreement was seen between them. By increasing the degree of conversion, the viscosity decreased; as the degree of conversion increased, so did the slope of viscosity. The results of the tack test also indicated that the highest tack could be obtained with 25% progress of curing.

scholarly journals Synthesis of Bisphenol A Based Phosphazene-Containing Epoxy Resin with Reduced Viscosity

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1914 ◽  
Author(s):  
Kireev ◽  
Bilichenko ◽  
Borisov ◽  
Mu ◽  
Kuznetsov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
31P Nmr ◽  
Diglycidyl Ether ◽  
31P Nmr Spectroscopy ◽  
Reduced Viscosity ◽  
Lower Viscosity ◽  
Curing Agents ◽  
Flame Retardant Properties

Phosphazene-containing epoxy oligomers (PEO) were synthesized by the interaction of hexachlorocyclotriphosphazene (HCP), phenol, and bisphenol A in a medium of excess of epichlorohydrin using potassium carbonate and hydroxide as HCl acceptors with the aim of obtaining a product with lower viscosity and higher phosphazene content. PEOs are mixtures of epoxycyclophosphazene (ECP) and a conventional organic epoxy resin based on bisphenol A in an amount controlled by the ratio of the initial mono- and diphenol. According to 31P NMR spectroscopy, pentasubstituted aryloxycyclotrophosphazene compounds predominate in the ECP composition. The relative content in the ECP radicals of mono- and diphenol was determined by the MALDI-TOF mass spectrometry method. The organic epoxy fraction, according to gas chromatograpy-mass spectrometry (GC-MS), contains 50–70 wt % diglycidyl ether of bisphenol A. PEO resins obtained in the present work have reduced viscosity when compared to other known phosphazene-containging epoxy resins while phosphazene content is still about 50 wt %. Resins with an epoxy number within 12–17 wt %, are cured by conventional curing agents to form compositions with flame-retardant properties, while other characteristics of these compositions are at the level of conventional epoxy materials.

scholarly journals Rheological and Electrical Study of a Composite Material Based on an Epoxy Polymer Containing Cyclotriphosphazene

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 921 ◽  
Author(s):  
O. Dagdag ◽  
M. El Gouri ◽  
A. El Mansouri ◽  
A. Outzourhit ◽  
A. El Harfi ◽  
...  
Keyword(s):  
Composite Material ◽  
Epoxy Resin ◽  
Room Temperature ◽  
Electrical Characterization ◽  
Small Deformation ◽  
Diglycidyl Ether ◽  
Localized States ◽  
Frequency Variation ◽  
Linear Viscoelastic ◽  
Electrical Study

In this work, we have studied, formulated, prepared, and characterized the rheological and electrical behavior of a composite material based on an epoxy resin Diglycidyl Ether of Bisphenol A (DGEBA) reinforced with hexaglycidyl cyclotriphosphazene (HGCP). The epoxy system was cured with 4,4’-methylene dianiline (MDA). DGEBA-HGCP-MDA epoxy composite materials with reinforced HGCP which varied from 5% to 10% by weight were prepared by mixing in the molten state. The morphology was evaluated by SEM. The rheological behavior was studied using small deformation rheology. The electrical characterization was carried out with a frequency variation range from 1 Hz to 100 KHz at room temperature. These measurements revealed that the rheological and electrical behaviors strongly depend on the quantity of HGCP in the DGEBA matrix. The linear viscoelastic properties study reveals that the modulus of elasticity G’ is dependent on the amount of HGCP present in the epoxy resin DGEBA. The capacitance-frequency measurements suggest a distribution of localized states in the band gap of the blends.

Fast Curing Epoxy and Episulfide Resins for Biomedical Applications

1987 ◽  
Vol 110 ◽  
Author(s):  
Ioannis N. Hadjinikolaou ◽  
James P. Bell ◽  
Larz Spangberg
Keyword(s):  
Bisphenol A ◽  
Physical Properties ◽  
Epoxy Resins ◽  
Biomedical Applications ◽  
Room Temperature ◽  
Diglycidyl Ether ◽  
Clinical Use ◽  
Curing Agent ◽  
Curing Agents

Epoxy resins have physical properties that make them suitable for dental and orthopaedic applications such as adhesives and cements. However, it has been observed that epoxy resins harden too slowly for clinical use when mixed with conventional curing agents, e.g. amines and polyamides. A new epoxy - diepisulfide - polyamide system has been developed which gels in 5 to 20 minutes at room temperature. The system consists of two parts: a polyamide curing agent, and a blend of the diepisulfide analog of diglycidyl ether of bisphenol A [DGEBA] dissolved in a mixture of epoxies of the DGEBA type.

Study of Thermal Properties of Curing of DGEBA Epoxy Resin with Hexakis-(4-Aminophenoxy)-Cyclotriphosphazene

2011 ◽  
Vol 284-286 ◽  
pp. 365-368 ◽  
Author(s):  
Jing Zhu ◽  
Yong Wu ◽  
Lei Zhao ◽  
Hong Liang Wei ◽  
Hui Juan Chu ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Thermogravimetric Analysis ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Chemical Structure ◽  
Diglycidyl Ether ◽  
Flame Retardance ◽  
Curing Agent ◽  
Degradation Behaviors ◽  
Curing Agents

Hexakis-(4-aminophenoxy)-cyclotriphosphazene (PN-NH2) was synthesized through nucleophilic substitution of the chloride atoms of hexachlorocyclotriphosphazene (HCCP) and reduction of the nitro group, and its chemical structure was characterized. As a curing agents for commercial epoxy resin Diglycidyl ether of bisphenol-A (DGEBA) PN-NH2 was compared with conventional curing agents 4,4-diaminodiphenylsulfone(DDS) and 4,4-diaminodiphenylmethane (DDM). The thermal properties and thermal degradation behaviors of these thermosetted resins were investigated by using thermogravimetric analysis (TGA). TGA studies demonstrated that the thermal properties of the PN-NH2-containing cured epoxy resin were higher than those of others. The phosphorus-nitrogen containing curing agent can result in a great improvement of the flame retardance for their thermosetted epoxy resins.

scholarly journals Development and Characterization of Novel Interpenetrating Network (IPN) Foams from Epoxy Ester and Aliphatic Epoxy Resin

2009 ◽  
Vol 6 (2) ◽  
pp. 341-347 ◽  
Author(s):  
Kanuprasad Patel ◽  
Dhirubhai Desai ◽  
Santosh Bhuva
Keyword(s):  
Epoxy Resin ◽  
Room Temperature ◽  
Glycidyl Ether ◽  
Diglycidyl Ether ◽  
Interpenetrating Network ◽  
Acrylate Monomer ◽  
Molar Ratios ◽  
Compression Properties ◽  
Rise Direction

Diglycidyl ether of bisphenol-A (DGEBA) was reacted with acrylate monomer at variable molar ratios. The reaction between glycerine and epichlorohydrine form glycidyl ether of polyol aliphatic epoxy resin. The resultant resins were characterized duly. Both the resins were mixed at different ratios with constant high shear stirring. The obtained mixture and suitable additives were heated at 150oC for one and half hour. The so called Interpenetrating Network (IPN) transformed into foams. The performance of foams was evaluated by testing for compression in both parallel and perpendicular to rise direction. The tests were carried out at room temperature and at the elevated temperature. The compression properties showed a decreasing trend for increasing amounts of glycerine resin. The density and thermal properties of epoxy foams were also evaluated. The relation between the composition, density and properties of the foam was analyzed.

Effect of trytophan as dopant on potassium acid phthalate single crystals

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Single Crystals ◽  
Room Temperature ◽  
Visible Region ◽  
X Ray Diffraction ◽  
X Ray ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Evaporation Technique ◽  
Potassium Acid Phthalate ◽  
Acid Phthalate

Optically transparent single crystals of potassium acid phthalate (KAP, 0.5 g) 0.05 g and 0.1 g (1 and 2 mol %) trytophan were grown in aqueous solution by slow evaporation technique at room temperature. Single crystal X- ray diffraction analysis confirmed the changes in the lattice parameters of the doped crystals. The presence of functional groups in the crystal lattice has been determined qualitatively by FTIR analysis. Optical absorption studies revealed that the doped crystals possess very low absorption in the entire visible region. The dielectric constant has been studied as a function of frequency for the doped crystals. The thermal stability was evaluated by TG-DSC analysis.

scholarly journals Ethoxylated Butoxyethanol-BADGE Adducts—New Potential Migrants from Epoxy Resin Can Coating Material

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3682
Author(s):  
Monika Beszterda ◽  
Małgorzata Kasperkowiak ◽  
Magdalena Frańska ◽  
Sandra Jęziołowska ◽  
Rafał Frański
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Liquid Chromatography ◽  
Epoxy Resin ◽  
Diglycidyl Ether ◽  
Ionization Mass ◽  
Coating Materials ◽  
Oxyethylene Unit ◽  
Bisphenol A Diglycidyl Ether ◽  
Product Ions

The acetonitrile extracts of can-coating materials have been analyzed by using high-pressure liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS). On the basis of detected ions [M + H]+, [M + NH4]+, [M + Na]+ and product ions, the ethoxylated butoxyethanol-bisphenol A diglycidyl ether adducts were identified in two of the analyzed extracts. Although the oxyethylene unit-containing compounds are widely used for the production of different kinds of materials, the ethoxylated species have not been earlier detected in epoxy resin can-coatings.

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