Enhancing thermal conductivity and physical properties of phenol‐formaldehyde resin by adding VGCF during pyrolysis

Abstract

ABSTRACT:After vapor-grown carbon-fibers (VGCF) were added to resol-type phenolic resin, their influence on microstructure, thermal conductivity, flexural strength, and physical properties of the resin was characterized in this work. Resin with content 0 -10 wt % VGCF was heat-treated at 230 -2500°C. As a result, it was observed that adding VGCF into resin during pyrolysis not only reduced weight loss but also limited shrinkage of resin. Moreover, adding VGCF to resin promoted the degree of arranging carbon basal planes and chemical densification of the structure of final heat-treated resins. At 2500°C, the graphitized resin with 10 wt % VGCF enhanced flexural strength and thermal conductivity over 300%, while decreasing weight loss around 20% versus graphitized phenol-formaldehyde resin developed from the original resin.

Excellent Thermal and Dielectric Properties of Hexagonal Boron Nitride/Phenolic Resin Bulk Composite Material for Heatsink Applications

“…The issue of heat-conducting properties of h-BN based compositions has had considerable attention in several studies [16,[18][19][20][21]24,[28][29][30][31][32][42][43][44][45][46][47]54]. Unfortunately, reported values of effective thermal conductivity were insufficient (no higher than 2.0 W•m −1 •K −1 ), since composites with relatively low-filler contents were obtained.…”

“…Experimental values were compared with three models that are most suitable for describing thermal conductivity in polymer composites. Thermal conductivity of pure h-BN was taken to be 100 W•m −1 •K −1 (taking into account possible local contact resistances), whereas thermal conductivity of the PR was 0.25 W•m −1 •K −1 [42]. Thermal conductivity of composites is a property that is difficult to describe adequately, since there may be substantial differences in the properties of components, i.e., 400 times in this case.…”

“…Dielectric properties of h-BN/PR systems are considered in detail by Ko et al [42], where electrically insulating properties of PR-based composite and mixture of two heatconducting fillers, h-BN and ZnO, were studied. PR was custom-made; nevertheless, thermal conductivity values were quite low (3.5 W•m −1 •K −1 in-plane and only ca.…”

Borax Modify Phenol-Formaldehyde Resin as Wood Adhesives

“…In order to meet these application requirements, many modifiers are used to modify the resins. A lot of literatures reveal that these resins were modified by sulfonated phenol-formaldehyde resin [2], organic acid esters [3], lignin [4][5], nitrogen, phosphorous [6], pyrolitic oil [7], and vapor-grown carbon-fiber [8]. By synthesizing copolymer [9][10], or introducing some heat-resistance chemical bonds, e.g., B-O bond, in the main chains [11], the thermal stability, low virulence and application temperature of PF resin can be improved to some extent.…”