Influence of matrix viscoelastic properties on thermal conductivity of TCA – Numerical approach

Fałat, Tomasz; Wymysłowski, Artur; Kolbe, Jana; Jansen, K.M.B.; Ernst, L.J.

doi:10.1016/j.microrel.2007.04.010

Cited by 13 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…According to the obtained values, C 1 increased with the addition of functionalized MWCNTs into epoxy matrix. The value of C 1 obtained from the empirical method is close to the universal value for the epoxy resin . Consequently, the free volume fraction, f g , at T g of all systems was calculated following the Eq .…”

Section: Resultsmentioning

confidence: 75%

“…The viscoelastic properties of thermosetting polymer, especially T g and CTE, can be explained in terms of free volume theory. This theory starts with a Williams‐Landell‐Ferry (WLF) equation, which is one of well‐known equations used to describe the material behavior with respect to temperature .…”

Section: Resultsmentioning

confidence: 99%

“…This theory starts with a Williams-Landell-Ferry (WLF) equation, which is one of well-known equations used to describe the material behavior with respect to temperature [32,33].…”

Section: Free Volume Characteristicmentioning

confidence: 99%

See 2 more Smart Citations

Direct functionalization with 3,5-substituted benzoic acids of multiwalled carbon nanotube/epoxy composites

2013

View full text Add to dashboard Cite

Directly functionalized multiwalled carbon nanotubes (MWCNTs) with benzene-1,3,5-tricarboxylic acid (BTC) and 3,5-diaminobenzoic acid (DAB) were successfully accomplished with less structural damage as confirmed by XPS and FT-Raman results. Their dispersibility and thermal stability were achieved after the functionalization. The functional groups on MWCNT surfaces can accelerate the curing reaction of epoxy composites remarkable inducing rather low exothermic peak temperature (T p ) and exothermic heat of reaction (DH). The values of activation energy (E a ) obtained from Kissinger and Ozawa methods obviously decreased with the introduction of MWCNTs, especially DAB-MWCNTs. The dynamic mechanical properties notably enhanced with the incorporation of unmodified and functionalized MWCNTs. The crosslink density (q) increased and free volume fraction (f g ) decreased, resulting in dramatic increase of glass transition temperatures (T g ) and decrease of coefficient of thermal expansion. Additionally, epoxy composites exhibited low dielectric constant close to that of neat epoxy resin. From these remarkable properties, MWCNT/epoxy composites can be considered as a good candidate for high performance insulation materials. POLYM. ENG. SCI., 53:2194-2204, 2013 ª 2013 Society of Plastics Engineers INTRODUCTIONMulti-Walled Carbon Nanotubes (MWCNTs) are one of the most attractive reinforcing fillers in the polymer composite systems due to the exceptional characteristic of MWCNTs including nanostructure, high aspect ratio, and intensively outstanding thermomechanical and thermal properties. Furthermore, MWCNTs exhibit extremely powerful performance with very low weight compared with various engineering materials, for example, MWCNTs are many times stronger than steel, though three to five times lighter [1]. Therefore, the incorporation of MWCNTs into the polymer matrix has been proposed for high performance and light-weight composites. The degree of dispersion of MWCNTs is an important role to realize the MWCNT reinforced polymer composites [2][3][4][5]. Generally, MWCNTs are hardly dispersed in any solvents, especially in viscous polymers, because of their high aspect ratio and high surface area. MWCNTs tend to agglomerate, bundle together and entangle. Besides, the interfacial interaction between CNT and polymer matrix is a critical issue for load transfer and heat transfer in polymer composite systems. Therefore, an approach to take advantage of their properties as predicted, achieving individual tube dispersion and good interfacial interaction between MWCNT and polymer matrix, is a challenge for MWCNT/polymer composites.MWCNTs were usually treated in harsh reaction conditions in strong acids like nitric acid and sulfuric acid and/or their mixtures at elevated temperatures [6,7]. The carboxylic groups and oxygen containing groups were introduced onto MWCNT surface facilitating further modification [8][9][10]. The defects on the sidewall of MWCNTs such as opening, breaking, and turning into amorphous carbon are initially ...

show abstract

Section: Resultsmentioning

confidence: 75%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Direct functionalization with 3,5-substituted benzoic acids of multiwalled carbon nanotube/epoxy composites

2013

View full text Add to dashboard Cite

show abstract

“…In the case of TCA, fillers can contact tightly with each other by the compression and shrinkage of the epoxy during the curing process (Su and Qu 2004;Falat et al 2007;Lu et al 1999). This idea can be reflected by the developed model.…”

Section: Resultsmentioning

confidence: 99%

Modeling of the effective thermal conductivity of composite materials with FEM based on resistor networks approach

Zhang

et al. 2010

Microsyst Technol

View full text Add to dashboard Cite

In the present paper, a novel and efficient model was developed for predicting the effective thermal conductivity of the composite materials at different filler percentages. By introducing the relative radius as a parameter, the effective thermal conductivity can be predicted precisely when the thermal properties of filler and matrix are prescribed. The model employed the resistor network strategy to achieve a highly efficient prediction during the overall conductivity calculation. To verify this model, a wide range of two-phase composites, including Cu/PP, AlN/PI and a self-developed thermal conductive adhesive, were analyzed. The model-based simulation values showed good agreement with the experimental results. Moreover, a discussion on the effects of the newlyintroduced parameter was given. Finally, the relationship between the filler radius variation and the thermal conductivity of the composite was studied.

show abstract

“…The effective thermal conductivity of a composite containing inorganic particles is a function of the thermal conductivity of the components, particle loading level, interface, impurities, size effects, shape (geometric parameters of the contact area between particles), thermo-mechanical properties of matrix and thermal interfacial resistance [2]. The thermal contact resistance between filler particles depends on the properties of the components and the geometric parameters of the contact area between the fillers [21,22]. Ineffective dispersion of the fillers in polymer matrix and agglomerates can lead to high thermal interfacial resistance and reduced thermal conductivity [20,23].…”

Section: Introductionmentioning

confidence: 99%

Photocurable acrylate-based composites with enhanced thermal conductivity containing boron and silicon nitrides

Sądej

Gojżewski

Gajewski

et al. 2018

Express Polym. Lett.

View full text Add to dashboard Cite

Boron nitride (BN) and silicon nitride (Si 3 N 4) are very promising particulate fillers for production of photocurable composites dedicated to thermally conductive and electrically insulating protective coatings. Composites containing crosslinked methacrylate-based matrices filled with BN or Si 3 N 4 (in amounts up to 5 wt%) were prepared in a fast in situ photocuring process with high conversion (>90%). The monomers were polyethylene glycol dimethacrylate and monomethacrylate (50/50 by weight mixture). Investigations included determination of properties of the monomer/filler compositions, photocuring kinetics and thermal, conductive and mechanical properties of the resulting composites. It was found that addition of the fillers improves polymerization kinetics and mechanical properties compared to the pure polymer matrix. Despite the very low loading level a substantial improvement in thermal conductivity was obtained: a 4-fold increase after addition of only 2 wt% of Si 3 N 4 and 2.5-fold increase after addition of 0.5 wt% of BN. SEM and AFM imaging (with nanoscopic Young's modulus determination) revealed good matrix-filler adhesion for the both types of fillers, tendency of the particles to be preferentially located in the bulk rather than at the interface and formation of thermally conducting paths (for the Si 3 N 4 filler).

show abstract

Influence of matrix viscoelastic properties on thermal conductivity of TCA – Numerical approach

Cited by 13 publications

References 12 publications

Direct functionalization with 3,5-substituted benzoic acids of multiwalled carbon nanotube/epoxy composites

Direct functionalization with 3,5-substituted benzoic acids of multiwalled carbon nanotube/epoxy composites

Modeling of the effective thermal conductivity of composite materials with FEM based on resistor networks approach

Photocurable acrylate-based composites with enhanced thermal conductivity containing boron and silicon nitrides

Contact Info

Product

Resources

About