Development of Thermally Conductive Polyurethane Composite by Low Filler Loading of Spherical BN/PMMA Composite Powder

Abstract

The issue of electronic heat dissipation has received much attention in recent times and has become one of the key factors in electronic components such as circuit boards. Therefore, designing of materials with good thermal conductivity is vital. In this work, a thermally conductive SBP/PU composite was prepared wherein the spherical h-BN@PMMA (SBP) composite powders were dispersed in the polyurethane (PU) matrix. The thermal conductivity of SBP was found to be significantly higher than that of the pure h-BN/PU composite at the same h-BN filler loading. The SBP/PU composite can reach a high thermal conductivity of 7.3 Wm−1 K−1 which is twice as high as that of pure h-BN/PU composite without surface treatment in the same condition. This enhancement in the property can be attributed to the uniform dispersion of SBP in the PU polymer matrix that leads to a three-dimensional continuous heat conduction thereby improving the heat diffusion of the entire composite. Hence, we provide a valuable method for preparing a 3-dimensional heat flow path in polyurethane composite, leading to a high thermal conductivity with a small amount of filler.

Generation of Self-Assembled 3D Network in TPU by Insertion of Al2O3/h-BN Hybrid for Thermal Conductivity Enhancement

“…However, when the components powders are composed of two different particle sizes, the radial segregation of particles occurs. Through the Brownian motion, smaller particles with the higher mobility occlude larger particles and therefore, according to this mechanism, surrounding or a coating of one component by others can be created [ 46 , 56 , 57 ].…”

“…In this work, we propose a facile and effective method to prepare thermally conductive composite constituting compact and continuous fillers. Firstly, the spheroidized three-dimensional functional hybrid fillers, Al 2 O 3 / h -BN (ABN), were prepared by mechanical mixing and spray drying processes [ 45 , 46 ]. Secondly, the ABN functional hybrid fillers were uniformly mixed with the TPU matrix through the melt-compounding process to form the ABN/TPU thermally conductive composite which was then made into a pellet by hot pressing.…”

Influence of Mouthwash Rinsing on the Mechanical Properties of Polymeric Ligature Ties Used for Dental Applications

“…From the results, shapes of FTIR spectra indicate that Brand A, C, and D ligature ties were made of similar materials and were different from those of Brand B. Based on the fact that the material components and additives of each brand are proprietary, it is impractical to precisely identify the material type of four ligature tie brands using the FTIR spectra alone, although they are likely to be of polyurethane family [ 1 , 28 , 29 ]. Nonetheless, it is understood from the FTIR spectra that rinsing with three commercial mouthwashes did not alter the molecular structure of polymeric orthodontic ligature ties as there was no significant change in the presence of peaks from the as-received samples.…”

Hypergravity-Induced Accumulation: A New, Efficient, and Simple Strategy to Improve the Thermal Conductivity of Boron Nitride Filled Polymer Composites

“…A variety of strategies have been developed. The most widely studied strategies include: (i) using a highly thermal conductive polymeric matrix such as nylon, liquid crystal polymers, or ultrahigh molecular weight polyethylene [ 10 , 11 , 12 ]; (ii) using highly thermal conductive fillers such as graphene, carbon nanotubes (CNTs), boron nitride (BN), and silver nanowires [ 13 , 14 , 15 ]; (iii) increasing filler concentration (volume fraction or mass fraction); (iv) dispersing thermal conductive fillers in a homogenous state [ 16 , 17 , 18 ]; (v) exfoliating two-dimensional (2D) thermal conductive fillers such as graphene and BN [ 19 , 20 , 21 ]; (vi) surface modification of thermal conductive fillers [ 22 , 23 , 24 ]; (vii) orientating thermal conductive fillers along one direction to promote the thermal conductivity in this direction [ 25 , 26 , 27 ]; (viii) making thermal conductive fillers into 3-dimensional (3D) porous structures which act as thermal conductive skeleton in the composites [ 28 , 29 , 30 ]; (ix) using two or more kinds of thermal conductive fillers or using one kind of filler with different sizes to obtain synergism; and (x) constructing thermal conductive pathways in the polymer matrix with templates [ 31 , 32 , 33 ]. These strategies can be used alone, or in combination.…”

“…(ix) using two or more kinds of thermal conductive fillers or using one kind of filler with different sizes to obtain synergism; and (x) constructing thermal conductive pathways in the polymer matrix with templates [31][32][33]. These strategies can be used alone, or in combination.…”