Synthesis of Two Novolac Type Epoxy Resin Curing Agents and their Application

2013 ◽  
Vol 634-638 ◽  
pp. 3008-3016
Author(s):  
Yan Li ◽  
Zhi Nan Zhou ◽  
Xiao Yan Xu ◽  
Long Xie
Keyword(s):  
Mechanical Properties ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Curing Kinetics ◽  
Mass Ratio ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Novolac Resins ◽  
Curing Agents ◽  
Resin Curing

Two Novolac Resins Were Synthesized by the Reaction between Bisphenol A and Benzaldehyde (bis-BENR) or Bisphenol A and P-hydroxybenzaldehyde (bis-PHNR). Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR) Were Applied to Characterize the Molecular Structure of Bis-BENR (or Bis-PHNR). then the Two Novolac Resins Were Used as Curing Agent for Bisphenol A Type Epoxy Resin (DGEBA). the Curing Reaction and Curing Kinetics Were Studied by Dynamic FTIR and Differential Scanning Calorimetry (DSC). Dynamic FTIR Showed that the Two Novolac Resins Reacted with Epoxy Resins and Formed a Crosslinking Network Structure. DSC Results Show that the Optimum Mass Ratio between DGEBA and Bis-BENR (or Bis-PHNR) Was 7:3, under which the Curing Reaction Processed Completely. the Mechanical Properties and Sulfide Resistance of DGEBA/bis-BENR (or Bis-PHNR) System Were Also Investigated. the Results Showed that when the Mass Ratio between DGEBA and Bis-BENR (or Bis-PHNR) Was 7:3, the Curing Coatings Had Optimum Mechanical Properties and Sulfide Resistance.

Curing Kinetics and Rheology of Diglycidyiether of Bisphenol-A Modified by Poly(ethylene glycol) Flexible Chains

2010 ◽  
Vol 123-125 ◽  
pp. 411-414 ◽  
Author(s):  
Da Hu Yao ◽  
Kyung Bok Sun ◽  
Peng Li ◽  
Joong Hee Lee
Keyword(s):  
Ethylene Glycol ◽  
Bisphenol A ◽  
Epoxy Resin ◽  
Kinetic Parameters ◽  
Curing Kinetics ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Exponential Factor ◽  
Curing Reaction ◽  
Poly Ethylene

The curing reaction of the system bisphenol-A glycidol ether epoxy resin modified by poly (ethylene glycol) (PEO) and flexible amine (D-230) as curing agent has been studied by means of differential scanning calorimetry (DSC) and thermal scanning rheometry. The curing kinetic parameters have been calculated from the non-thermal DSC curve. The kinetic analysis suggests that the two-parameter autocatalytic model is more appropriate to describe the kinetics of the curing reaction of the system. Increasing the PU content leads to an increase in the heat of curing and has a little effect on the kinetic parameters apparent activation energy (Ea), pre-exponential factor (A), and order of the reaction (m and n). The rheological properties were measured by isothermal curing evolution. Introduction of PEO flexible chains delayed the polymerization. It has been confirmed that the introduction of PEO chains in the structure of the epoxy resin increases the mobility of the molecular segment of the epoxy networks and results in the decrease in glass transition temperature.

Curing study and evaluation of epoxy resin with amine functional chloroaniline acetaldehyde condensate

2015 ◽  
Vol 44 (1) ◽  
pp. 19-25
Author(s):  
T. Maity ◽  
B.C. Samanta
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Epoxy Resin ◽  
Ph Value ◽  
Kinetic Studies ◽  
Diglycidyl Ether ◽  
Curing Agent ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Curing Reaction

Purpose – The purpose of this paper was to check effectiveness of amine functional chloroaniline acetaldehyde condensate (AFCAC) as a new curing agent for diglycidyl ether of bisphenol A (DGEBA) resin. For this purpose, first AFCAC was synthesised, characterised and then curing reaction was carried out. Design/methodology/approach – Equimolecular mixture of AFCAC and DGEBA was subjected to curing reaction, and the reaction was followed by differential scanning calorimetry (DSC) analysis. The kinetic studies of this curing reaction were also carried out from those DSC exotherms. The mechanical properties, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) of cured epoxy were also reported. Findings – DSC results reflected the effective first order curing reaction of AFCAC with epoxy resin. Mechanical properties reflected appreciable rigidity of AFCAC cured epoxy matrix and TGA showed that the cured epoxy networks were thermally stable up to around 297°C. Research limitations/implications – The curing agent AFCAC was synthesised by using chloroaniline and acetaldehyde in acid medium. There are some limitations for this procedure. The synthetic procedure is pH dependent. So reaction cannot be done at any pH value. The reaction must also be carried out at room temperature without any heating. To obtain low molecular weight curing agent, chloroaniline and acetaldehyde cannot be taken in equimolecular ratio because the equimolecular mixture of them produces high molecular weight condensate. This was shown in our previous publication. Some implications are also there. By changing amine and aldehyde other curing agents could be synthesised and the curing efficiency of those for epoxy resin could also be studied. Originality/value – Experimental results revealed the greater suitability of AFCAC as curing agent for DGEBA resin and novelty of AFCAC cured matrix in the field of protective coating, casting, adhesives, etc.

scholarly journals Curing Kinetics and Mechanism Research of E44/T31 Insulation Paint

2019 ◽  
Vol 25 (4) ◽  
pp. 478-484
Author(s):  
Haoqing XU ◽  
Yuan FANG ◽  
Aizhao ZHOU ◽  
Pengming JIANG ◽  
Shi SHU ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Epoxy Group ◽  
Curing Kinetics ◽  
Curing Temperature ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Rate Versus ◽  
Reaction Orders ◽  
Dsc Method ◽  
Kinetics Of

Epoxy resin insulation paint was prepared with epoxy resin (E44) as binder and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by the differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was investigated by using the phenomenological method, and the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determined. The curing reaction mechanism of paint was ascertained by the dynamic temperature DSC method and IR spectroscopy (FTIR) method. The results show that the Kamal model can be used to describe the curing kinetics of epoxy resin paint, and the total reaction orders increase from 1.30 to 2.14. The two rate constants increase with the increase of the curing temperature. The activation energy is 90.5832 kJ/mol and 68.3733 kJ/mol respectively, and the pre-exponential factors are 6.521 × 1015 s-1 and 6.3807 × 109 s-1. The curing reaction of paint consists of two steps: the first step is the addition reaction of epoxy group and primary amine or secondary amine; the second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl. Epoxy resin insulation paint was prepared with epoxy resin (E44) as binders and with proper inorganic fillers and curing agent (T31) as additives. The isothermal curing reaction process of paint was studied by differential scanning calorimetry method (DSC), and the curves of curing reaction rate versus time of paint were obtained. The curing reaction kinetics was studied by using the phenomenological method, the corresponding parameters of the n-order model, autocatalytic model and Kamal model were determined by fitting the experimental data, respectively. According to the values of R2 and the sum of square due to error (SSE), a suitable curing reaction kinetic model was determind. The curing reaction mechanism of paint was ascertained by dynamic temperature DSC method and IR spectrogram (FTIR) method. The results show that the kamal model can be used to describe the curing kinetics of epoxy resin paint, the total reaction orders increase from 1.30 to 2.14. The results also show that the two rate constants increase with increasing curing temperature, The activation energies are 90.5832 kJ/mol and 68.3733 kJ/mol, and the pre-exponential factor are 6.521×1015 s-1 and 6.3807×109 s-1. The curing reaction of paint in two steps, the first step is the addition reaction of epoxy group and primary amine or secondary amine. The second step is the etherification reaction of epoxy group and phenolic hydroxyl or alcoholic hydroxyl.

scholarly journals Novel Bio-Based Epoxy Thermosets Based on Triglycidyl Phloroglucinol Prepared by Thiol-Epoxy Reaction

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 337 ◽  
Author(s):  
Dailyn Guzmán ◽  
David Santiago ◽  
Àngels Serra ◽  
Francesc Ferrando
Keyword(s):  
Mechanical Properties ◽  
Thermal Analysis ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Bisphenol A ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
High Transparency ◽  
Epoxy Curing ◽  
Curing Agents

The pure trifunctional glycidyl monomer from phloroglucinol (3EPO-Ph) was synthesized and used as feedstock in the preparation of novel bio-based thermosets by thiol-epoxy curing. The monomer was crosslinked with different commercially available thiols: tetrafunctional thiol (PETMP), trifunctional thiol (TTMP) and an aromatic dithiol (TBBT) as curing agents in the presence of a base. As catalyst, two different commercial catalysts: LC-80 and 4-(N,N-dimethylamino) pyridine (DMAP) and a synthetic catalyst, imidazolium tetraphenylborate (base generator, BG) were employed. The curing of the reactive mixtures was studied by using DSC and the obtained materials by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The results revealed that only the formulations catalyzed by BG showed a latent character. Already prepared thermosetting materials showed excellent thermal, thermomechanical and mechanical properties, with a high transparency. In addition to that, when compared with the diglycidyl ether of bisphenol A (DGEBA)/PETMP material, the thermosets prepared from the triglycidyl derivative of phloroglucinol have better final characteristics and therefore this derivative can be considered as a partial or total renewable substitute of DGEBA in technological applications.

scholarly journals Effect of enzymatically hydrolyzed lignin on the curing characteristics of epoxy resin/polyamine blends

BioResources ◽  
2017 ◽  
Vol 12 (4) ◽  
pp. 7793-7806 ◽  
Author(s):  
Sen Wang ◽  
Yayun Lai ◽  
Yalan Yu ◽  
Mingwei Di ◽  
Junyou Shi
Keyword(s):  
Epoxy Resin ◽  
Bending Strength ◽  
Curing Kinetics ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Reaction Conversion ◽  
Hydrolyzed Lignin ◽  
Autocatalytic Curing ◽  
Reaction Processes ◽  
The Impact

Corn stalk enzymatically hydrolyzed lignin (EHL) was used to modify bisphenol A-type epoxy resin. The curing reaction processes of the epoxy resin/polyamine blends and the lignin/epoxy resin/polyamine blends were studied via isothermal differential scanning calorimetry (DSC), and the effect of enzymatically hydrolyzed lignin on the curing reaction of epoxy resin was also analyzed. The results showed that the curing kinetics for two blends were not in full compliance with the autocatalytic curing kinetic model, especially the lignin/epoxy resin/polyamine blends. The apparent activation energy of the epoxy resin/polyamine blends increased with the increased presence of the lignin. The presence of enzymatically hydrolyzed lignin was beneficial to the curing process of epoxy resin/polyamine blends at high temperatures. The addition of the lignin increased the final curing reaction conversion rate, improved the glass transition temperature (Tg) and increased the bending strength for the epoxy resin/polyamine blends. However, the impact strength decreased in this process.

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.

Epoxy resin curing reaction studied by proton multiple-quantum NMR

2015 ◽  
Vol 53 (18) ◽  
pp. 1324-1332 ◽  
Author(s):  
Mario Martin-Gallego ◽  
Antonio González-Jiménez ◽  
Raquel Verdejo ◽  
Miguel Angel Lopez-Manchado ◽  
Juan Lopez Valentin
Keyword(s):  
Epoxy Resin ◽  
Multiple Quantum ◽  
Curing Reaction ◽  
Resin Curing ◽  
Multiple Quantum Nmr

scholarly journals Preparation and Characterization of Green Epoxy Resin Composites and Its Use in Corrosion Resistance

2018 ◽  
Author(s):  
Abbas Hassan Faris
Keyword(s):  
Bisphenol A ◽  
Epoxy Resin ◽  
Electrolyte Solutions ◽  
Kraft Lignin ◽  
Diglycidyl Ether ◽  
Kraft Pulping ◽  
Palm Tree ◽  
Scanning Calorimetry ◽  
Ft Ir ◽  
Nano Titanium Dioxide

In this work, appropriate alternative for diglycidyl ether bisphenol A (DGEBA) was found to avoid the destructive effects of bisphenol A. Lignin, an aromatic compound from palm tree leaves, was used as a renewable material to synthesize a bio-based epoxy resin. Lignin extracted using Kraft pulping process. Kraft Lignin was epoxidized with epichlorohydrin in alkaline medium. Nano-titanium dioxide was used as filler with ratio of 10% to prepare the green epoxy composite. The structure of the Kraft lignin and lignin-based epoxy resin was proven via Infrared spectra (FT-IR) were recorded using solid KBr disk by testing Shimadzu (FT-IR-8300) spectrophotometer. The thermal properties of the curing process of lignin-based epoxy resin and composite were investigate using Differential scanning calorimetry (DSC) analysis. Potentiodynamic measurements data revealed that the anti-corrosion performance of the lignin based epoxy resin. The study demonstrates successful of epoxidation of Kraft lignin. In addition, lignin based eopxy resin showed effective inhibitor for carbon steel in 3.5 wt. % NaCl electrolyte solutions

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