scholarly journals Cold-Cured Bisphenolic Epoxy Adhesive Filled with Low Amounts of CaCO3: Effect of the Filler on the Durability to Aqueous Environments

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1324
Author(s):  
Anna Rudawska ◽  
Mariaenrica Frigione
Keyword(s):  
Mechanical Properties ◽  
Mannich Base ◽  
Filler Content ◽  
Epoxy Adhesive ◽  
Compressive Modulus ◽  
Curing Agent ◽  
Aqueous Environments ◽  
Curing Agents ◽  
Effects Of Aging ◽  
Manova Analysis

The effects of aging exposures to three non-saline aqueous environments on the compressive mechanical properties of a calcium carbonate-filled bisphenolic epoxy adhesive, cold-cured with the addition of two curing agents suitable for the cure at ambient temperature (i.e., Mannich base and triethylenetetramine), were assessed. The amount of the added filler (CaCO3) varied from 1 to 3 g per 100 g of resin; the immersion times in each of the selected medium varied from 1 to 10 months. It was found that the mechanical properties measured in compression mode on cylindrical specimens of unfilled and CaCO3-loaded epoxy were scarcely influenced by the kind of curing agent employed; only the compressive modulus was limitedly affected by this parameter. Referring to the behavior when aged in water, the CaCO3-filled epoxies displayed noticeable growths in modulus, small reductions in strength, and limited variations in strain, with a certain influence of the exposure time, especially when comparing the properties at the lowest time with those at medium–long times. On the basis of the results of statistical MANOVA analysis, it can be concluded that among the compositional factors (i.e., the type of curing agent employed to cure the epoxy compounds and the micro-filler content), only the amount of CaCO3 filler significantly affects the compressive modulus.

scholarly journals Thermal analysis of halogenated rubber cured with a new cross-linking system

2019 ◽  
Vol 138 (6) ◽  
pp. 4395-4405 ◽  
Author(s):  
Anna Dziemidkiewicz ◽  
Magdalena Maciejewska ◽  
Martyna Pingot
Keyword(s):  
Mechanical Properties ◽  
Cross Linking ◽  
Curing Agent ◽  
Metal Acetylacetonates ◽  
Damping Properties ◽  
Rubber Blends ◽  
Rubber Compounds ◽  
Curing Agents ◽  
Brominated Butyl Rubber ◽  
Thermal Stability Of

Abstract The aim of this work was to examine the influence of new curing agents proposed for brominated butyl rubber (BIIR) on the cross-linking process of rubber compounds and the thermal behavior of the vulcanizates. Rubber blends that were filled with carbon black and contained acetylacetonates of different transition metals in the presence of triethanolamine (TEOA) as new cross-linking agents were prepared. The performed studies showed that metal acetylacetonates (Me(acac)) are effective cross-linking agents for BIIR, which was confirmed by high values of the torque increment (∆M) and significant cross-linking degree of the vulcanizates (α(T)). The most active curing agent seems to be iron acetylacetonate (Fe(acac)). Its application results in a shorter optimal vulcanization time, lower onset vulcanization temperature and similar vulcanization enthalpy compared to the BIIR cured with a sulfur curing system. The BIIR vulcanizates cured with Me(acac) reveal good mechanical properties with tensile strengths in the range of 9–14 MPa and better damping properties comparing to the sulfur-cured rubber. The proposed curing agents do not significantly affect the thermal stability of the BIIR vulcanizates.

Solvent Exchange to Exfoliate Graphene Oxides into Epoxy with Improved Mechanical and Thermal Properties

2015 ◽  
Vol 1110 ◽  
pp. 69-72
Author(s):  
Fu Ke Wang ◽  
Chao Bin He
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Mechanical And Thermal Properties ◽  
Curing Agent ◽  
Solvent Exchange ◽  
Thermal And Mechanical Properties ◽  
Graphene Oxides ◽  
Curing Agents ◽  
Exchange Technique

The dispersion and exfoliation of graphene oxides in polymer matrix remains a challenge for graphene oxides based epoxy nanocomposites fabrication. In the present paper, we reported a simple and facile solvent exchange technique to successfully transfer graphene oxides (GOs) from aqueous solution to ethanol. In addition, we found that GO dispersion in epoxy resins was affected by the curing agents. Good dispersion of GOs in epoxy resin together with enhanced thermal and mechanical properties were observed when epoxy was cured with aliphatic curing agents. For aromatic curing agent, high loading of GOs leaded to GOs aggregation, but well dispersed GOs was observed at low loading of GOs. Especially, a 12 °C increase of glass transition temperature of the epoxy resin was observed with only 0.1 wt% GOs was added to the epoxy resin.

scholarly journals Mechanical Properties of Selected Epoxy Adhesive and Adhesive Joints of Steel Sheets

2021 ◽  
Vol 2 (1) ◽  
pp. 108-126
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Experimental Tests ◽  
Epoxy Adhesive ◽  
Adhesive Joints ◽  
Stoichiometric Ratio ◽  
Curing Agent ◽  
Steel Sheets ◽  
Epoxy Adhesives ◽  
Strength Tests

The article presents the issues of the mechanical properties of epoxy adhesives and the adhesive joints strength of steel sheets which were made using the epoxy adhesives. The aim of the paper is to study the mechanical properties of epoxy adhesive of different epoxy resin/curing agent ratios (within and above the recommended stoichiometric ratio) and their effect on mechanical properties of adhesive joints of steel sheets. In experimental tests three types of epoxy adhesives, containing a low molecular weight epoxy resin based on bisphenol A and polyamide curing agent, were used. A single-lap adhesive joint type of stainless-steel sheets was also applied. Two types of strength test were used: the compressive strength tests (DIN EN 196-1) for epoxy adhesive samples and the shear strength tests (DIN EN 1465) for adhesive joints. Both the analysis of the strength results of the samples of epoxy adhesive and adhesive joints as well as the failure analysis was carried out. On the basis of the results of strength tests it can be stated that the greatest deformation occurred for the samples of epoxy adhesive containing the modified epoxy resin (epoxy number—0.40) and the polyamide curing agent, and the smallest for the samples of epoxy adhesive containing the basic epoxy resin (epoxy number—0.49–0.52) and the polyamide curing agent. The epoxy adhesives with a smaller amount of curing agent were characterized by higher strength. This applies to all analyzed epoxy resins. The same dependences were obtained for the strength of adhesive joints of steel sheets made of the analyzed epoxy adhesive.

Thermal Stability of an Epoxy Adhesive

2014 ◽  
Vol 1053 ◽  
pp. 257-262
Author(s):  
Mei Li ◽  
Xiang Yu Zhao ◽  
Wei Shao ◽  
Chuan Bao Ma ◽  
Rui Xue Zheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Thermal Properties ◽  
Epoxy Adhesive ◽  
Inert Gas ◽  
Curing Agent ◽  
Pure Epoxy ◽  
Different Levels ◽  
Thermal Stability Of ◽  
Better Than

An epoxy adhesive and its curing agent are tested using differential scaning calorimetry under different atmospheres and after different exposure times to natural air to analyze its thermal properties. The results show that after the pure epoxy, the curing agent and the adhesive mixture of them are exposed in natural air for different period of time, all show different levels of decline in thermal stability and more complicated reactions when tested in the DSC and TGA in O2 and air, while the thermal properties remain stable when they are tested in an inert gas like N2. And according to the mechanical property tests and SEM results, the mechanical properties of the adhesive mixture in N2 are better than that in air. The results indicate that inert gas can protect the property of this kind of adhesive and thus increase its bond strength.

scholarly journals The Effect of the Salt Water Aging on the Mechanical Properties of Epoxy Adhesives Compounds

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 843 ◽  
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Calcium Carbonate ◽  
Salt Water ◽  
Tap Water ◽  
Testing Machine ◽  
Epoxy Adhesive ◽  
Curing Agent ◽  
Epoxy Adhesives ◽  
Adhesive Compound ◽  
Strength Tests

The objective of this study is to compare the effect of selected operating factors on the mechanical properties of epoxy adhesive compounds aged in salt water. Five different water environments were tested: tap water, normal seawater (reference salinity value), seawater with double reference salinity value, seawater with half of the reference salinity and seawater with a quarter of the reference salinity value. Samples of two different adhesive compounds were prepared using the epoxy resin and triethylenetetramine curing agent. One of the compounds was filled with calcium carbonate. The samples were aged in five different water environments for three months, one month and one week, respectively. Mechanical properties of the cured adhesive compound samples were determined via strength tests performed on the Zwick/Roell Z150 testing machine in compliance with the EN ISO 604 standard. The objective of the experiments was to determine the effect of different seawater environments on selected mechanical properties (including strength) of the fabricated adhesive compounds.

scholarly journals The Impact of the Seasoning Conditions on Mechanical Properties of Modified and Unmodified Epoxy Adhesive Compounds

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 804 ◽  
Author(s):  
Anna Rudawska
Keyword(s):  
Mechanical Properties ◽  
Ambient Temperature ◽  
Testing Machine ◽  
Negative Temperature ◽  
Epoxy Adhesive ◽  
Adhesive Compound ◽  
Strength Tests ◽  
Curing Agents ◽  
Amine Curing ◽  
The Impact

The aim of this study was to analyse the impact of the adhesive samples seasoning conditions (temperature and time) on selected mechanical properties of four epoxy adhesive compounds (two unmodified and two modified ones). The samples were made of Epidian 53 epoxy resin mixed with the two different amine curing agents in appropriate stoichiometric proportions. A filler in the form of calcium carbonate (CaCO3) powder was used as a modifier. The adhesive compound samples were cured for seven days. Six seasoning variants were used. Four of them were related with the seasoning time at ambient temperature of 24 ± 2 °C for: one month, two months, five months and eight months, respectively. Two other variants were related with seasoning at negative temperature (−10 ± 2 °C) for one month. The last variant (F) also included seasoning at ambient temperature (24 ± 2 °C) for five months right after seasoning in negative temperature. Cured and cylinder-shaped adhesive compound samples were subjected to compressive strength tests (according to the ISO 604 standard). The strength tests were performed using a Zwick/Roell Z150 testing machine. Based on the tests, it was observed that both temperature and time of seasoning influenced the adhesive’s mechanical properties. In the perspective of eight months, these changes were relatively minor for the samples seasoned at ambient temperature. The adhesive samples prepared for the tests were especially sensitive to negative temperature.

Study on the Properties of Epoxy Thermosets Cured by ImHBPs under Lower Temperature

2010 ◽  
Vol 150-151 ◽  
pp. 651-654
Author(s):  
Bao Hua Zhang ◽  
Bin Chen ◽  
Hong Xu ◽  
Yan Qing Weng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Low Temperature ◽  
Impact Strength ◽  
Diglycidyl Ether ◽  
Curing Agent ◽  
Hyperbranched Polyesters ◽  
Epoxy Curing ◽  
Curing Agents ◽  
Lower Temperature

The 2-methylimidazole (Im) -terminated hyperbranched polyesters (ImHBPs) with different generations were prepared and used in diglycidyl ether of bisphenol A (DGEBA) as curing agents and tougheners in this work. It was found that the ImHBPs had better latent property than Im which indicated that the ImHBPs were proper to be used as low temperature curing agent in epoxy curing system. It was also found that the tensile strength, the flexural strength and impact strength of epoxy thermosets cured by ImHBPs under 90 were much higher than those of CYD-128/2-methylimidazole thermoset, which indicated that the ImHBPs obviously improved the mechanical properties of epoxy thermosets, and the thermoset cured by ImHBP with two generation had the best performance among the thermosets.

Comparison of different curing method for mechanical properties of self-curing agent using diapers polymer

2021 ◽  
Author(s):  
Daud Mohamad ◽  
Salmia Beddu ◽  
Ibrahim ◽  
Karim Sherif ◽  
Mahyun Zainoddin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Curing Agent ◽  
Curing Method

Determination of mechanical properties of two-phase and hybrid nanocomposites: experimental determination and multiscale modeling

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Mahmoud Haghighi ◽  
Hossein Golestanian ◽  
Farshid Aghadavoudi
Keyword(s):  
Mechanical Properties ◽  
Ultimate Strength ◽  
Multiscale Modeling ◽  
Filler Content ◽  
Hybrid Nanocomposites ◽  
Dynamics Simulation ◽  
Strength Increase ◽  
Two Phase ◽  
Macro Scale ◽  
Elongation To Failure

Abstract In this paper, the effects of filler content and the use of hybrid nanofillers on agglomeration and nanocomposite mechanical properties such as elastic moduli, ultimate strength and elongation to failure are investigated experimentally. In addition, thermoset epoxy-based two-phase and hybrid nanocomposites are simulated using multiscale modeling techniques. First, molecular dynamics simulation is carried out at nanoscale considering the interphase. Next, finite element method and micromechanical modeling are used for micro and macro scale modeling of nanocomposites. Nanocomposite samples containing carbon nanotubes, graphene nanoplatelets, and hybrid nanofillers with different filler contents are prepared and are tested. Also, field emission scanning electron microscopy is used to take micrographs from samples’ fracture surfaces. The results indicate that in two-phase nanocomposites, elastic modulus and ultimate strength increase while nanocomposite elongation to failure decreases with reinforcement weight fraction. In addition, nanofiller agglomeration occurred at high nanofiller contents especially higher than 0.75 wt% in the two-phase nanocomposites. Nanofiller agglomeration was observed to be much lower in the hybrid nanocomposite samples. Therefore, using hybrid nanofillers delays/prevents agglomeration and improves mechanical properties of nanocomposite at the same total filler content.

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