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

Abstract

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).

High-Performance Thermal Management Nanocomposites: Silver Functionalized Graphene Nanosheets and Multiwalled Carbon Nanotube

“…The thermal conductivities of composites greatly depended on the properties of polymers and fillers, such as their content, components, and surface treatment of fillers [49][50][51][52][53][54]. Comparison charts of thermal conductivities and their enhancements for GNS/PVA, MWCNT/PVA, (GNS-MWCNT)/PVA, and (GNS-MWCNT)@AgNPs/PVA composite films with different nanofillers are shown in Figure 4.…”

High-Performance Thermal Management Nanocomposites: Silver Functionalized Graphene Nanosheets and Multiwalled Carbon Nanotube

“…The thermal conductivities of composites greatly depended on the properties of polymers and fillers, such as their content, components, and surface treatment of fillers [49][50][51][52][53][54]. Comparison charts of thermal conductivities and their enhancements for GNS/PVA, MWCNT/PVA, (GNS- The thermal conductivities of composites greatly depended on the properties of polymers and fillers, such as their content, components, and surface treatment of fillers [49][50][51][52][53][54]. Comparison charts of thermal conductivities and their enhancements for GNS/PVA, MWCNT/PVA, (GNS-MWCNT)/PVA, and (GNS-MWCNT)@AgNPs/PVA composite films with different nanofillers are shown in Figure 4.…”

Polyurethane composites with enhanced thermal conductivity containing boron nitrides

“…A number of articles have been devoted to polymer composite containing BN particles, but they focused on the preparation of thermally conductive composites polymer based mainly on silicone rubber [3], epoxy resin or epoxy-thiol system [4][5][6], polyimide [7] or (meth)acrylate matrix [8,9]. Bulk-sized boron nitride nanotube and hexagonal boron nitride nanosheets have been used as a fillers only in thermoplastic polyurethane elastomer [10][11][12].…”

“…In our continuing investigations on preparation and properties of PUR foam [14] we undertook research concerning a filler -boron nitride. The effects of content and particle size of BN and Si 3 N 4 filler on the thermal conductivity and mechanical property of methacrylate were studied in the previous studies [9]. It was found that addition of the fillers improves polymerization kinetics and mechanical properties of the polymer matrix.…”

“…It was found that addition of the fillers improves polymerization kinetics and mechanical properties of the polymer matrix. Despite the very low loading level a substantial improvement in thermal conductivity was obtained: 2.5-fold increase after addition of 0.5 wt % of BN [9]. Therefore, boron nitride represent promising polymer fillers, and have the potential to significantly improve properties of composites, especially their ability to transfer heat (because heat dissipation is a crucial point for the electronic devices).…”