Effect of Moisture Absorption on the Fracture Toughness and Morphology of Halloysite Nanoclay-Epoxy Nanocomposites

2020 ◽  
Author(s):  
ALEXANDRA GRANTHAM ◽  
THOMAS MOCKLER ◽  
SHAINAZ LANDGE ◽  
ERMIAS G. KORICHO
Keyword(s):  
Fracture Toughness ◽  
Moisture Absorption ◽  
Epoxy Nanocomposites ◽  
Effect Of Moisture

Effect Of Moisture On The Physical Properties Of Polyimide Films

1991 ◽  
Vol 227 ◽  
Author(s):  
Rajeevi Subramanian ◽  
Michael T. Pottiger ◽  
Jacqueline H. Morris ◽  
Joseph P. Curilla
Keyword(s):  
Dielectric Constant ◽  
Steady State ◽  
Electrical Properties ◽  
Relative Humidity ◽  
Quartz Crystal ◽  
Moisture Absorption ◽  
Relative Dielectric Constant ◽  
Moisture Uptake ◽  
Polyimide Films ◽  
Effect Of Moisture

ABSTRACTMoisture absorption and its effect on electrical properties were measured for several polyimides. A Quartz Crystal Microbalance (QCM) was used to investigate the moisture absorption in BPDA/PPD, PMDA/ODA, and BTDA//ODA/MPD polyimides. The steady-state moisture uptake in polyimides as a function of relative humidity (RH) was determined by exposing film samples to successively higher RH values ranging from 10 to 85% at 25°C. The isothermal moisture absorption as a function of percent RH was found to be nearly linear for all of the polyimides studied. The effect of moisture on the electrical properties of a BPDA/PPD polyimide was also investigated. The relative dielectric constant at 25 °C was found to be a linear function of the moisture absorbed.

scholarly journals Moisture Absorption of Carbon/Epoxy Nanocomposites

2020 ◽  
Vol 4 (1) ◽  
pp. 21 ◽  
Author(s):  
Gorkem E. Guloglu ◽  
M. Cengiz Altan
Keyword(s):  
Carbon Nanomaterials ◽  
Moisture Absorption ◽  
Accurate Determination ◽  
Type Model ◽  
Graphite Nanoplatelets ◽  
Epoxy Nanocomposites ◽  
Thermal Environments ◽  
Thermogravimetric Data ◽  
Hindered Diffusion ◽  
Molecular Bonding

Moisture absorption of composites with nanoscale carbon additives such as carbon nanotubes, carbon nanofibers, graphite nanoplatelets, and carbon black is investigated using thermogravimetric data and a non-Fickian hindered diffusion (Langmuir-type) model. The moisture absorption parameters are determined using this model for six different types of carbon/epoxy nanocomposites. The absorption behaviors obtained at different humidity levels and thermal environments are recovered by minimizing the error between the experimental data and model predictions, thus enabling the accurate determination of the moisture equilibrium level. The absorption behavior and the weight gain of all nanocomposites are shown to be accurately represented by this model over the entire absorption period. The presence of carbon nanomaterials is found to induce varying levels of non-Fickian behavior, governed by the nondimensional hindrance coefficient. This behavior is enhanced with the nanomaterial content and separate from the slight non-Fickian behavior of all neat epoxy samples. The molecular bonding during diffusion, as well as the interfacial moisture storage, could be among the reasons for non-Fickian behavior and should be included in the absorption models for accurate characterization of carbon/epoxy nanocomposites.

scholarly journals Moisture Absorption Effects on Mode II Delamination of Carbon/Epoxy Composites

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2162
Author(s):  
King Jye Wong ◽  
Mahzan Johar ◽  
Seyed Saeid Rahimian Koloor ◽  
Michal Petrů ◽  
Mohd Nasir Tamin
Keyword(s):  
Fracture Toughness ◽  
Moisture Content ◽  
Composite Structures ◽  
Moisture Absorption ◽  
Peak Load ◽  
Epoxy Composites ◽  
Mode Ii ◽  
Damage Initiation ◽  
Residual Properties ◽  
Mode Ii Fracture Toughness

It is necessary to consider the influence of moisture damage on the interlaminar fracture toughness for composite structures that are used for outdoor applications. However, the studies on the progressive variation of the fracture toughness as a function of moisture content M (%) is rather limited. In this regard, this study focuses on the characterization of mode II delamination of carbon/epoxy composites conditioned at 70 °C/85% relative humidity (RH). End-notched flexure test is conducted for specimens aged at various moisture absorption levels. Experimental results reveal that mode II fracture toughness degrades with the moisture content, with a maximum of 23% decrement. A residual property model is used to predict the variation of the fracture toughness with the moisture content. Through numerical simulations, it is found that the approaches used to estimate the lamina and cohesive properties are suitable to obtain reliable simulation results. In addition, the damage initiation is noticed during the early loading stage; however, the complete damage is only observed when the numerical peak load is achieved. Results from the present research could serve as guidelines to predict the residual properties and simulate the mode II delamination behavior under moisture attack.

DEA and DSC study of cubic silsesquioxane epoxy resin nanocomposites

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Newton Luiz Dias Filho ◽  
Hermes Adolfo de Aquino
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Fracture Toughness ◽  
Differential Scanning Calorimetry ◽  
Epoxy Resin ◽  
Loss Factor ◽  
Tensile Modulus ◽  
Dielectric Analysis ◽  
Epoxy Nanocomposites ◽  
Scanning Calorimetry

AbstractNon-isothermal dielectric analysis (DEA) and differential scanning calorimetry (DSC) techniques were used to study the epoxy nanocomposites prepared by reacting 1,3,5,7,9,11,13,15-octa[dimethylsiloxypropylglycidylether] pentaciclo [9.5.1.13,9.15,15 .17,13] octasilsesquioxane (ODPG) with methylenedianiline (MDA). Loss factor (ε”) and activation energy were calculated by DEA. The relationships between the loss factor, the activation energy, the structure of the network, and the mechanical properties were investigated. Activation energies determined by DEA and DSC, heat of polymerization, fracture toughness and tensile modulus show the same profile for mechanical properties with respect to ODPG content.

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