Flame-retardant poly(vinyl alcohol)/MXene multilayered films with outstanding electromagnetic interference shielding and thermal conductive performances

Factors affecting thermal conductivities of the polymers and polymer composites: A review

Enhanced thermal conductivities of epoxy nanocomposites via incorporating in-situ fabricated hetero-structured SiC-BNNS fillers

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A comprehensive review on mechanical, electromagnetic radiation shielding, and thermal conductivity of fibers/inorganic fillers reinforced hybrid polymer composites

In recent decades, problems with electromagnetic interference (EMI) radiation problems have arisen, that can seriously reduce the performance of precision devices nearby and threaten human health. In consequence, it is important to seek high efficiency materials to suppress EMI pollution. Generally, high magnetic permeability or electrical conductivity is essential for efficient EMI shielding. Conventionally, various forms of metal construction (sheet/films, coatings, etc.) are used for EMI shielding. However, metallic shielding has drawbacks that include high density, lack of corrosion resistance and expensive processing, which restrict its use in the modern electronic world. By contrast, conductive polymer composites (CPCs), formed from insulative polymers and conductive fillers, have attracted more and more interest from both industry and academia. CPCs have properties that offer great potential for application in efficient EMI shielding. These include low density, high flexibility, good chemical stability and easy processing and forming. From a theoretical viewpoint, it is generally accepted that the shielding of EM waves is due to the three basic mechanisms of reflection, absorption and multiple internal reflections. However, it must be recognized that the SE of CPCs has a close relation to the reflection mechanism, which can cause secondary EMI pollution. Therefore, materials with charge carriers or magnetic/electric dipoles as well as cellular structure should be the focus for the development of EMI shielding materials with strong absorption properties. On that basis, the main aim of this paper is to review the current position in research of the design of inorganic based foams (metal, carbon or MXene) and polymer composite foams as EMI shielding materials. On the one hand, these composite foams have the merit of being lightweight, and on the other hand, the special porous structure can effectively harvest microwaves by prolonging the travel path. As a result, absorption dominates EMI shielding, which satisfies current requirements of EMI shielding applications. This review also points out the future challenges and gives guidelines for finding solutions for the next generation of shielding applications using composite foams.

Advances in electromagnetic shielding properties of composite foams

Anisotropic thermal conductivity and electromagnetic interference shielding of epoxy nanocomposites based on magnetic driving reduced graphene oxide@Fe3O4

A new multifunctional ionic liquid-based metal–organic hybrid (PMAIL) was synthesized by anion exchange between as-synthesized phosphonate-based ionic liquid and phosphomolybdic acid and applied to epoxy resin (EP) as an efficient flame retardant. As expected, with only 1 wt% addition of PMAIL, the char yield of EP-PMAIL1 composite at 700 °C was significantly improved by 108.3% from 12.0% for neat epoxy resin to 25.0%, demonstrating the outstanding catalytic charring effect of PMAIL. Meanwhile, EP-PMAIL6 composite (6 wt% addition) can reach V-0 rating in the UL-94 vertical burning tests easily, and its peak heat release rate and total smoke production of EP-PMAIL6 were dropped by 31.0 and 15.4%, respectively, compared with neat EP. Moreover, the results from cone calorimetry tests showed that the char yield of EP-PMAIL6 was enhanced by 162% from 9.5 to 24.9% compared with neat EP, resulting in a strong intumescent char layer structure with outstanding fire retardance and mechanical properties. The thermo-oxidative stable protective layer retarded the transfer of heat and flammable volatiles during combustion and protected the epoxy matrix from further degradation. In conclusion, our results might provide a new perspective for producing composites with excellent flame retardancy and smoke suppression properties using ionic liquid-based metal–organic hybrid.

Influence of Ionic Liquid-Based Metal–Organic Hybrid on Thermal Degradation, Flame Retardancy, and Smoke Suppression Properties of Epoxy Resin Composites

In this work, a cycloaliphatic epoxy resin hexahydrophthalic acid bis(3,4-epoxycyclohexylmethyl) ester (BE) was prepared and cured with anhydride. The curing kinetics and properties of the cycloaliphatic epoxy resin were characterized and compared with (3′,4′-epoxycyclohexane) methyl-3,4-epoxycyclohexyl-carboxylate (CE) and bis(3,4-epoxycyclohexylmethyl) adipate (BA). The result shows that BE/4-methyl hexahydrophthalic anhydride (MHHPA) exhibits a higher reaction activation energy and a slower curing rate than CE/MHHPA and BA/MHHPA. The loss modulus of BE/MHHPA increased 53 and 24% compared to CE/MHHPA and BA/MHHPA, respectively. The Young’s modulus and initial degradation temperature of BE/MHHPA improved 31 and 6.4% compared with those of BA/MHHPA. Furthermore, superior moisture resistance and dielectric properties are expressed for BE/MHHPA among these epoxy resins. Those results demonstrated the potential usefulness of BE/MHHPA in the electronic packaging materials field.

Sa Yao

Papers

Anisotropic thermal conductivity and electromagnetic interference shielding of epoxy nanocomposites based on magnetic driving reduced graphene oxide@Fe3O4

Influence of Ionic Liquid-Based Metal–Organic Hybrid on Thermal Degradation, Flame Retardancy, and Smoke Suppression Properties of Epoxy Resin Composites

Cure Kinetics and Properties of High Performance Cycloaliphatic Epoxy Resins Cured with Anhydride

Preparation, Characterization and Application of Cyclodextrin-Containing UV-Curable Waterborne Polyurethane Based on Guest Regulation