Thermal dissipation is a critical aspect for the performance and lifetime of electronic devices. In this work, novel composites based on a cycloaliphatic epoxy matrix and BN fillers, obtained by cationic curing of mixtures of 3,4‐epoxy cyclohexylmethyl 3,4‐epoxy cyclohexane carboxylate (ECC) with several amounts of hexagonal boron nitride (BN) were prepared and characterized. As cationic initiator a commercial benzylanilinium salt was used, which by addition of triethanolamine, exhibited an excellent latent character and storage stability. The effect of the formulation composition was studied by calorimetry and rheological measurements. The variation of thermal conductivity, thermal stability, thermal expansion coefficient, and thermomechanical and mechanical properties of the composites with the load of BN filler (ranging from 10 to 40 wt%) was evaluated. An improvement of an 800% (1.04 W/m·K) in thermal conductivity was reached in materials with glass transition temperatures >200°C without any loss in electrical insulation. POLYM. COMPOS., 39:E1760–E1769, 2018. © 2018 Society of Plastics Engineers

A series of boron nitride (BN) composites, with different BN content, were prepared and characterized by cationic curing of DGEBA/BN formulations. As cationic initiator a commercial benzylanilinium salt was used. This cationic system shows good latent characteristics that were not lost on adding the filler. The performance of the catalytic system was optimized by varying the amount of initiator and adding little proportions of glycerol. The kinetics of the curing process was evaluated by calorimetric measurements. The addition of BN allowed increasing thermal conductivity without loss of mechanical properties like Young modulus, impact resistance, adhesion and other thermal characteristics like Tg or thermal stability. In addition, dielectric properties were improved with the increment of filler.Postprint (author's final draft

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In this work, the effect of the addition of boron nitride (BN) fillers in a thiol-cycloaliphatic epoxy formulation has been investigated. Calorimetric studies put into evidence that the kinetics of the curing has been scarcely affected and that the addition of particles does not affect the final structure of the network. Rheologic studies have shown the increase in the viscoelastic properties on adding the filler and allow the percolation threshold to be calculated, which was found to be 35.5%. The use of BN agglomerates of bigger size increases notably the viscosity of the formulation. Glass transition temperatures are not affected by the filler added, but Young’s modulus and hardness have been notably enhanced. Thermal conductivity of the composites prepared shows a linear increase with the proportion of BN particle sheets added, reaching a maximum of 0.97 W/K·m. The addition of 80 μm agglomerates, allowed to increase this value until 1.75 W/K·m.

Novel composite coatings prepared from 3,4-epoxy cyclohexylmethyl 3,4-epoxycyclohexane carboxylate (ECC) and different ceramic fillers have been prepared to improve the thermal dissipation of electronic devices. As latent cationic initiator, a benzylanilinium salt with triethanolamine has been used, which leads to a polyether matrix. Different proportions of Al2O3, AlN and SiC as fillers were added to the reactive formulation. The effect of the fillers selected and their proportions on the evolution of the curing was studied by calorimetry and rheometry. The thermal conductivity, thermal stability, thermal expansion coefficient and thermomechanical and mechanical properties of the composites were evaluated. An improvement of 820% in thermal conductivity in reference to the neat material was reached with a 75 wt % of AlN, whereas glass transition temperatures higher than 200 °C were determined in all the composites.