The Study of Epoxy Resins Modified By PPESK

2012 ◽  
Vol 463-464 ◽  
pp. 181-184
Author(s):  
Ya Juan Xu ◽  
Qin Cun Cao ◽  
Xi Gao Jian
Keyword(s):  
Fracture Toughness ◽  
Critical Stress Intensity Factor ◽  
Diglycidyl Ether ◽  
Fracture Mechanisms ◽  
Moderate Increase ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Accelerated Curing ◽  
The Matrix ◽  
Kinetics Of

A series of blends have been prepared by adding a novel thermoplastic poly (phthalazinone ether sulfone ketone) (PPESK) in varying proportions to diglycidyl ether of bisphenol A epoxy resin (DGEBA) cured with p-diaminodiphenylsulfone. The kinetics of curing reaction and glass transition temperature (Tg) of PPESK/DGEBA blends were performed using differential scanning calorimetry (DSC) technique. It is proved that the addition of PPESK accelerated curing reaction and resulted in great enhancement of thermal properties of the blends. There was moderate increase in the fracture toughness as estimated by the critical stress intensity factor (KIc). Compared to that of unmodified epoxy, the maximum toughness of the modified blends had increased 32% by addition of 15 phr PPESK. Fracture mechanisms such as crack deflection and branches, ductile microcracks, ductile tearing of the thermoplastic of the matrix were responsible for the increase in the fracture toughness of the blends

Fracture Toughening of Epoxy Resins by Addition of a Novel Thermoplastic PPAEs

2012 ◽  
Vol 161 ◽  
pp. 153-156 ◽  
Author(s):  
Ya Juan Xu ◽  
Si Kai Zhou ◽  
Xi Gao Jian
Keyword(s):  
Fracture Toughness ◽  
Epoxy Resins ◽  
Diglycidyl Ether ◽  
Fracture Mechanisms ◽  
Moderate Increase ◽  
Aryl Ether ◽  
Scanning Calorimetry ◽  
Fracture Toughening ◽  
The Matrix ◽  
Unmodified Epoxy

A series of blends have been prepared by adding a novel thermoplastic Poly (aryl ether) s containing phthalazinone moiety (PPAEs) in varying proportions to diglycidyl ether of bisphenol A epoxy resin (DGEBA) cured with p-diaminodiphenylsulfone (DDS). The glass transition temperature (Tg) of DGEBA /PPAEs blends were performed using differential scanning calorimetry (DSC) technique. It is proved that the addition of PPAEs resulted in enhancement of thermal properties of the blends, especially PPENK. There was moderate increase in the fracture toughness as estimated by notched impact strength. Compared to that of unmodified epoxy, the maximum toughness of the modified blends had increased 44% by addition of 15 phr PPENK. Fracture mechanisms such as plastic deformation and the ductile nature of the crack of the matrix were responsible for the increase in the fracture toughness of the blends.

Kinetics of the Curing Reaction of a Diglycidyl Ether of Bisphenol with a Methanol Etherified Amino Resin

2011 ◽  
Vol 380 ◽  
pp. 60-63 ◽  
Author(s):  
Yong Lv ◽  
Zhu Long ◽  
Shi Yong Luo ◽  
Lei Dai
Keyword(s):  
Cure Kinetics ◽  
Frequency Factor ◽  
Diglycidyl Ether ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Before And After ◽  
Amino Resin ◽  
Chemical Products ◽  
Kinetics Of

Subscript text Subscript textEpoxy resins have been widely used for inner coating in food can and other chemical products storage containers. Differential scanning calorimetry (DSC) was used at different heating rates to study the cure kinetics of the diglycidyl ether of bisphenol A (DGEBA) with a methanol etherified amino resin (MEAR). The apparent activation energy derived from Kissinger and Ozawa methods is 35.67KJ/mol and 40.27kJ/mol, respectively. The reaction order evaluated by Crane equation is 0. 95 and the frequency factor is 1.12×104s-1. Reaction mechanism was monitored by FTIR spectra of the reaction mixtures before and after curing. The curing reaction below 200°C is between alkoxylmethyl (>NCH2OCH3) and epoxide group, not between alkoxylmethyl and hydroxyls.

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 Thermal Kinetics of SiCp Reinforced Al-Zn-Mg-Cu Alloy Composite

2021 ◽  
Author(s):  
Saikat Das ◽  
R. Govinda Rao ◽  
Prasanta Kumar Rout
Keyword(s):  
Base Alloy ◽  
Accelerated Aging ◽  
Stir Casting ◽  
Hardness Profile ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
The Matrix ◽  
Aging Kinetics ◽  
Aging Phenomena ◽  
Kinetics Of

Abstract In the present work, the artificial aging kinetics of SiCp particles reinforced AA7075-SiCp composite fabricated by stir casting method was investigated. The aging behavior of AA7075-SiCp composite was investigated by Rockwell hardness tests and differential scanning calorimetry (DSC). Results show there are no changes in the sequences of formation and dissolution of precipitate. Reinforced particles are uniformly distributed throughout the matrix. The hardness profile shows increase in hardness with the comparison of AA7075 base alloy. In addition to SiCp in the matrix, precipitation kinetics has changed compared with base alloy since higher dislocations present in composite, hence requires lower activation energy to form ή precipitate and takes less time to reach the maximum hardness. In contrast, the addition of SiCp at low volume percent also showing accelerated aging phenomena in the composite during the aging process. High-resolution transmission electron microscope (HRTEM) micrograph of peak age (T6) condition divulges that enormous fine and plate-like ή (MgZn2) precipitates are uniformly distributed in the composite.

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 Dynamic Cure Kinetics and Physical-Mechanical Properties of PEG/Nanosilica/Epoxy Composites

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Haleh Nowruzi Varzeghani ◽  
Iraj Amiri Amraei ◽  
Seyed Rasoul Mousavi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cure Kinetics ◽  
Diglycidyl Ether ◽  
Solid Particles ◽  
Scanning Calorimetry ◽  
Cure Reaction ◽  
Cure Kinetic ◽  
Cure Temperature ◽  
Kinetics Of

This study investigated the effect of polyethylene glycol (PEG) and nanosilica (NS) on the physical-mechanical properties and cure kinetics of diglycidyl ether of bisphenol-A-based epoxy (DGEBA-based EP) resin. For this purpose, tensile and viscometry tests, dynamic mechanical thermal analysis (DMTA), and differential scanning calorimetry (DSC) were carried out under dynamic conditions. The results showed that adding NS and PEG enhances the maximum cure temperature as well as the heat of cure reaction (ΔH) in EP-NS, while it decreases in EP-PEG and EP-PEG-NS. The cure kinetic parameters of EP-PEG-NS were calculated by Kissinger, Ozawa, and KSA methods and compared with each other. The Ea calculated from the Kissinger method (96.82 kJ/mol) was found to be lower than that of the Ozawa method (98.69 kJ/mol). Also, according to the KAS method, the apparent Ea was approximately constant within the 10-90% conversion range. Tensile strength and modulus increased by adding NS, while tensile strength diminished slightly by adding PEG to EP-NS. The glass transition temperature (Tg) was calculated using DMTA which was increased and decreased by the addition of NS and PEG, respectively. The results of the viscometry test showed that the viscosity increased with the presence of both PEG and NS and it prevented the deposition of solid particles.

Kinetics of the curing reaction of a diglycidyl ether of bisphenol A with a modified polyamine

2005 ◽  
Vol 438 (1-2) ◽  
pp. 126-129 ◽  
Author(s):  
Alessia Catalani ◽  
Maria Grazia Bonicelli
Keyword(s):  
Bisphenol A ◽  
Diglycidyl Ether ◽  
Curing Reaction ◽  
Kinetics Of

scholarly journals Curing Reaction Kinetics of the EHTPB-Based PBX Binder System and Its Mechanical Properties

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1266
Author(s):  
Xing Zhang ◽  
Yucun Liu ◽  
Tao Chai ◽  
Zhongliang Ma ◽  
Kanghui Jia
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Reaction Kinetics ◽  
Testing Machine ◽  
Curing Process ◽  
Binder System ◽  
Isophorone Diisocyanate ◽  
Scanning Calorimetry ◽  
Curing Reaction ◽  
Kinetics Of

In this research, differential scanning calorimetry (DSC) was employed to compare the curing reaction kinetics of the epoxidized hydroxyl terminated polybutadiene-isophorone diisocyanate (EHTPB-IPDI) and hydroxyl terminated polybutadiene-isophorone diisocyanate (HTPB-IPDI) binder systems. Glass transition temperature (Tg) and mechanical properties of the EHTPB-IPDI and HTPB-IPDI binder systems were determined using the DSC method and a universal testing machine, respectively. For the EHTPB-IPDI binder system, the change of viscosity during the curing process in the presence of dibutyltin silicate (DBTDL) and tin 2-ethylhexanoate (TECH) catalysts was studied, and the activation energy was estimated. The results show that the activation energies (Ea) of the curing reaction of the EHTPB-IPDI and HTPB-IPDI binder systems are 53.8 and 59.1 kJ·mol−1, respectively. While their average initial curing temperatures of the two systems are 178.2 and 189.5 °C, respectively. The EHTPB-IPDI binder system exhibits a higher reactivity. Compared with the HTPB-IPDI binder system, the Tg of the EHTPB-IPDI binder system is increased by 5 °C. Its tensile strength and tear strength are increased by 12% and 17%, respectively, while its elongation at break is reduced by 10%. Epoxy groups and isocyanates react to form oxazolidinones, thereby improving the mechanical properties and thermal stability of polyurethane materials. These differences indicate that the EHTPB-IPDI binder system has better thermal stability and mechanical properties. During the EHTPB-IPDI binder system’s curing process, the DBTDL catalyst may ensure a higher viscosity growth rate, indicating a better catalytic effect, consistent with the prediction results obtained using the non-isothermal kinetic analysis method.

scholarly journals Aromatic Hyperbranched Polyester/RTM6 Epoxy Resin for EXTREME Dynamic Loading Aeronautical Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 188 ◽  
Author(s):  
Aldobenedetto Zotti ◽  
Ahmed Elmahdy ◽  
Simona Zuppolini ◽  
Anna Borriello ◽  
Patricia Verleysen ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Dynamic Compression ◽  
Condensation Reaction ◽  
Glassy State ◽  
Rate Sensitivity ◽  
Strain Energy Release ◽  
Critical Stress Intensity Factor ◽  
Hyperbranched Polyester ◽  
Compression Tests ◽  
Scanning Calorimetry

The effects of the addition of an aromatic hyperbranched polyester (AHBP) on thermal, mechanical, and fracture toughness properties of a thermosetting resin system were investigated. AHBP filler, synthesized by using a bulk poly-condensation reaction, reveals a glassy state at room temperature. Indeed, according to differential scanning calorimetry measurements, the glass transition temperature (Tg) of AHBP is 95 °C. Three different adduct weight percentages were employed to manufacture the AHBP/epoxy samples, respectively, 0.1, 1, and 5 wt%. Dynamical Mechanical Analysis tests revealed that the addition of AHBP induces a negligible variation in terms of conservative modulus, whereas a slight Tg reduction of about 4 °C was observed at 5 wt% of filler content. Fracture toughness results showed an improvement of both critical stress intensity factor (+18%) and critical strain energy release rate (+83%) by adding 5 wt% of AHBP compared to the neat epoxy matrix. Static and dynamic compression tests covering strain rates ranging from 0.0008 to 1000 s−1 revealed a pronounced strain rate sensitivity for all AHBP/epoxy systems. The AHBP composites all showed an increase of the true peak yield compressive strength with the best improvement associated with the sample with 0.1 wt% of AHBP.

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