The effect of resin/hardener stoichiometry on the electrical properties of silicon nitride/epoxy nanocomposites

Alhabill, F. N.; Andritsch, Thomas; Vaughan, A. S.

doi:10.1109/icd.2016.7547553

Cited by 5 publications

(4 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The surface chemistry of the silicon nitride is characterized by the existence of amine and hydroxyl groups (oxynitride surface chemistry) [44,45]. Previous work has shown that the amine hydrogens can chemically react with the epoxy groups in the resin [46,47]. On one hand, this has the advantage of making silicon nitride inherently compatible with the matrix polymer, which should result in good particle dispersion and, thus, minimize the effect of particle agglomeration.…”

Section: Methodsmentioning

confidence: 99%

“…Table 1 summarizes the prepared samples along with relevant details; the procedures used to prepare these samples are detailed elsewhere [46,47] and, consequently, are not repeated here, for the sake of brevity. All samples were stored under vacuum for at least two weeks prior to examination [54], in order to ensure that they were dry before any data were acquired.…”

Section: Nanocomposite Preparationmentioning

confidence: 99%

See 1 more Smart Citation

Introducing particle interphase model for describing the electrical behaviour of nanodielectrics

et al. 2018

View full text Add to dashboard Cite

This study proposes a new model for describing the electrical behavior of nanocomposites. Unlike other models in the literature, this model has concentrated on the role of an interphase layer within the boundaries of nanoparticles. The experimental part investigates this role by filling an epoxy matrix with two types of surface-modified silicon nitride nanofiller: (a) the particles were dried at 200 o C, and (b) the particles were calcinated at 1050 o C. Electrical characterization showed that the epoxy which was filled with the calcinated particles has considerably better dielectric performance. Given that thermal and dielectric spectroscopy results demonstrate that the matrix molecular dynamics and polar content are comparable for all the investigated samples, the variations in the dielectric performance point to the particle interphase as an essential reason. As shown by infrared spectroscopy, the complex surface chemistry of the dried particles suggests a particle interphase with a high concentration of localized electronic states, which may enhance charge transport through hopping/tunnelling conduction. On the other hand, calcinating the particles results in a particle interphase with wider band gap, which may work as an energy barrier for charge movement. Consequently, this study highlights the paramount importance of particle interphase for designing dielectric properties of nanodielectrics.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Nanocomposite Preparationmentioning

confidence: 99%

Introducing particle interphase model for describing the electrical behaviour of nanodielectrics

et al. 2018

View full text Add to dashboard Cite

show abstract

“…These properties are highly sensitive to the presence of dielectric e.g. metallic nano-particles with high microwave absorption properties [106][107][108][109], and can also be affected by sample preparation [49,56,[110][111][112][113][114][115], moisture [116][117][118], and temperature [119,120]. There has also been a slight confusion of using different terms as 'dielectric constant' in different literatures.…”

Section: Dielectric Properties Of Compositesmentioning

confidence: 99%

Accelerated microwave curing of fibre-reinforced thermoset polymer composites for structural applications: A review of scientific challenges

Mgbemena

Lin

et al. 2018

Composites Part A: Applied Science and Manufacturing

123

View full text Add to dashboard Cite

Accelerated curing of high performance fibre-reinforced polymer (FRP) composites via microwave heating or radiation, which can significantly reduce cure time and increase energy efficiency, has several major challenges (e.g. uneven depth of radiation penetration, reinforcing fibre shielding, uneven curing, introduction of hot spots etc). This article reviews the current scientific challenges with microwave curing of FRP composites considering the underlying physics of microwave radiation absorption in thermoset-matrix composites. The fundamental principles behind efficient accelerated curing of composites using microwave radiation heating are reviewed and presented, especially focusing on the relation between penetration depth, microwave frequency, dielectric properties and cure degree. Based on this review, major factors influencing microwave curing of thermoset-matrix composites are identified, and recommendations for efficient cure cycle design are provided.

show abstract

“…Indeed, an investigation by Nguyen et al [12] of epoxy resins demonstrated the marked reduction in dielectric breakdown strength that occurs when systems are formulated using an unbalanced stoichiometry. Separate work has demonstrated that the presence of unreacted amines can markedly increase electrical conductivity [13]. Although such results cannot demonstrate unambiguously that residual functional groups degrade the electrical properties of cured epoxy resins, they do highlight stoichiometry as a relevant and contributory factor.…”

Section: Introductionmentioning

confidence: 95%

Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

et al. 2021

View full text Add to dashboard Cite

Reactive molecular additives have often been employed to tailor the mechanical properties of epoxy resins. In addition, several studies have reported improved electrical properties in such systems, where the network architecture and included function groups have been modified through the use of so-called functional network modifier (FNM) molecules. The study reported here set out to investigate the effect of a glycidyl polyhedral oligomeric silsesquioxane (GPOSS) FNM on the cross-linking reactions, glass transition, breakdown strength and dielectric properties of an amine-cured epoxy resin system. Since many previous studies have considered POSS to act as an inorganic filler, a key aim was to consider the impact of GPOSS addition on the stoichiometry of curing. Fourier transform infrared spectroscopy revealed significant changes in the cross-linking reactions that occur if appropriate stoichiometric compensation is not made for the additional epoxide groups present on the GPOSS. These changes, in concert with the direct effect of the GPOSS itself, influence the glass transition temperature, dielectric breakdown behaviour and dielectric response of the system. Specifically, the work shows that the inclusion of GPOSS can result in beneficial changes in electrical properties, but that these gains are easily lost if consequential changes in the matrix polymer are not appropriately counteracted. Nevertheless, if the system is appropriately optimized, materials with pronounced improvements in technologically important characteristics can be designed.

show abstract

The effect of resin/hardener stoichiometry on the electrical properties of silicon nitride/epoxy nanocomposites

Cited by 5 publications

References 16 publications

Introducing particle interphase model for describing the electrical behaviour of nanodielectrics

Introducing particle interphase model for describing the electrical behaviour of nanodielectrics

Accelerated microwave curing of fibre-reinforced thermoset polymer composites for structural applications: A review of scientific challenges

Investigation of the functional network modifier loading on the stoichiometric ratio of epoxy resins and their dielectric properties

Contact Info

Product

Resources

About