Mechanichal Properties of DGEBA/TEPA Modified Epoxy Resin

2014 ◽  
Vol 775-776 ◽  
pp. 588-592
Author(s):  
Camila Rodrigues Amaral ◽  
Ruben Jesus Sanchez Rodriguez ◽  
Magno Luiz Tavares Bessa ◽  
Verônica Scarpini Cândido ◽  
Sergio Neves Monteiro

The correlation between the structural network of a diglycidyl ether of the bisphenol-A (DGEBA) epoxy resin, modified by two distinct aliphatic amines (tetraethylenepentamine TEPA and jeffamine D230), and its mechanical properties, was investigated as possible matrix for abrasive composites applications. Both flexural tests, to determine the yield stress and the elastic modulus, as well as impact tests to determine the notch toughness, were performed. The DGEBA/D230 presented the highest stiffness and toughness but lowest yield stress. This epoxy network also displayed a greater plastic deformation during fracture.

2014 ◽  
Vol 910 ◽  
pp. 70-73
Author(s):  
Tao Wang ◽  
Jun Wang ◽  
Bin Zhang

P(BA-St), a good modifier for epoxy resin, was prepared by BA and St in situ polymerization. The modified resin system was based on diglycidyl ether of bisphenol and methyl tetrahydrophthalic anhydride, tris (dimethylaminomethyl) phenol. The influence of the copolymer on mechanical properties and thermal performance of the systems was studied. When 15 wt% of the BA/St with a weight ratio composition of 7.5/7.5 was added to epoxy, high performance modified epoxy resin was obtained.


Author(s):  
Georgel MIHU ◽  
Claudia Veronica UNGUREANU ◽  
Vasile BRIA ◽  
Marina BUNEA ◽  
Rodica CHIHAI PEȚU ◽  
...  

Epoxy resins have been presenting a lot of scientific and technical interests and organic modified epoxy resins have recently receiving a great deal of attention. For obtaining the composite materials with good mechanical proprieties, a large variety of organic modification agents were used. For this study gluten and gelatin had been used as modifying agents thinking that their dispersion inside the polymer could increase the polymer biocompatibility. Equal amounts of the proteins were milled together and the obtained compound was used to form 1 to 5% weight ratios organic agents modified epoxy materials. To highlight the effect of these proteins in epoxy matrix mechanical tests as three-point bending and compression were performed.


2021 ◽  
Author(s):  
SAGAR M. DOSHI, SAGAR M. DOSHI, ◽  
NITHINKUMAR MANOHARAN ◽  
BAZLE Z. (GAMA) HAQUE, ◽  
JOSEPH DEITZEL ◽  
JOHN W. GILLESPIE, JR.

Epoxy resin-based composite panels used for armors may be subjected to a wide range of operating temperatures (-55°C to 76°C) and high strain rates on the order of 103-104 s-1. Over the life cycle, various environmental factors also affect the resin properties and hence influence the performance of the composites. Therefore, it is critical to determine the stress-strain behavior of the epoxy resin over a wide range of strain rates and temperatures for accurate multi-scale modeling of composites and to investigate the influence of environmental aging on the resin properties. Additionally, the characterization of key mechanical properties such as yield stress, modulus, and energy absorption (i.e. area under the stress-strain curve) at varying temperatures and moisture can provide critical data to calculate the material operating limits. In this study, we characterize mechanical properties of neat epoxy resin, SC-15 (currently used in structural armor) and RDL-RDC using uniaxial compression testing. RDL-RDC, developed by Huntsman Corporation, has a glass transition temperature of ~ 120°C, compared to ~ 85°C of SC-15. A split Hopkinson pressure bar is used for high strain rate testing. Quasistatic testing is conducted using a screw-driven testing machine (Instron 4484) at 10-3 s-1 and 10-1 s-1 strain rates and varying temperatures. The yield stress is fit to a modified Eyring model over the varying strain rates at room temperature. For rapid investigation of resistance to environmental aging, accelerated aging tests are conducted by immersing the specimens in 100°C water for 48 hours. Specimens are conditioned in an environmental chamber at 76 °C and 88% RH until they reach equilibrium. Tests are then conducted at five different temperatures from 0°C to 95°C, and key mechanical properties are then plotted vs. temperature. The results presented are an important step towards developing a methodology to identify environmental operating conditions for composite ground vehicle applications.


2017 ◽  
Vol 757 ◽  
pp. 62-67 ◽  
Author(s):  
Kritsanachai Leelachai ◽  
Supissara Ruksanak ◽  
Tarakol Hongkeab ◽  
Supakeat Kambutong ◽  
Raymond A. Pearson ◽  
...  

In this study, diglycidyl ether of bisphenol A (DGEBA) cured cycloaliphatic polyamine was modified with functionalized celluloses for improved thermal and mechanical properties. Three different types of surface-modified cellulose, polyacrylamide-g-cellulose (PGC), aminopropoxysilane-g-cellulose (SGC), and carboxymethyl cellulose (CMC), were investigated and used as reinforcing agents in epoxy resins. The storage modulus of these modified epoxy systems was found to significantly increase with addition of cellulose fillers (up to 1 wt. % cellulose content). An improved fracture toughness (KIC) was also observed with increasing cellulose loading content with PGC and SGC. Among the surface-modified celluloses, epoxy modified with SGC was found to have the highest fracture toughness followed by PGC and CMC at 1.0 wt.% cellulose addition due to the chemical surface compatibility. The toughening mechanisms of the cellulose/epoxy composites, measured by scanning electron microscopy (SEM), revealed that fiber-debonding, fiber-bridging, and fiber-pull out were responsible for increased toughness.


2015 ◽  
Vol 44 (1) ◽  
pp. 19-25
Author(s):  
T. Maity ◽  
B.C. Samanta

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.


2011 ◽  
Vol 415-417 ◽  
pp. 35-38 ◽  
Author(s):  
Guang Qing Gai ◽  
Xiang Ting Dong ◽  
Xue Song Chen ◽  
Cheng Yan Zheng

The nano-particle modified epoxy resin adhesive was prepared by adding different types of nanoparticles to the epoxy resin adhesives.The influence of the kinds and amount of nanoparticles on the mechanical properties of epoxy resin adhesive was investigated.The investigation results indicated that the addition of three kinds of nanoparticles including nano-silica,nano-titanium dioxide,nano zinc oxide to epoxy resin adhesive has a significant influence on the mechanical properties of nano-composites.And tensile strength and breaking elongation of nano-composites reached the maximum when the amount of nanoparticle reached 4wt%.In addition,the toughening mechanisms of nano-particles modified epoxy resin adhesives was analysed.


2018 ◽  
Vol 139 ◽  
pp. 259-267 ◽  
Author(s):  
M.R. Ricciardi ◽  
I. Papa ◽  
A. Langella ◽  
T. Langella ◽  
V. Lopresto ◽  
...  

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