The needle-like Al2O3–ZnO nanowire hybrid filler endows polymer composites with high thermal conductivity, mechanical and thermal properties.

No abstract

Polylactic acid (PLA)/thermoplastic urethane (TPU)/boron nitride (BN) composites were successfully prepared, the effect of microstructure evolution along with the compositional change and annealing treatment on the thermal conductivity of composite was investigated. Owing to the selective distribution of BN in low-viscosity TPU phase, the compactness of thermally conductive networks in PLA/TPU/BN composites was reinforced. Thereby, the thermal conductivity of PLA/TPU/BN composites was obviously improved by 21.6% at 25 wt-% BN than that of PLA/BN composites. Moreover, research on the effect of annealing treatment on the thermal conductivity of composites found that the crystallinity of PLA had been improved by the recrystallisation and the thermal conductivities of composites were enhanced. Finally, due to the possible hydrogen bonding between PLA and TPU, PLA/TPU/ BN composites showed no serious deterioration in mechanical properties. This work endows new enlightenment to fabricate composites with great thermal conductivity without causing serious damage to mechanical properties.

To develop thermally conductive PA6 composites with the aim of decreasing filler content, structure-complexed fillers were fabricated. This research presented an effective approach by noncovalent functionalization of poly(dopamine) (PDA) followed by silver nanoparticles decoration to fabricate 3-dimensional (3-D) structured boron nitride hybrids (BN@PDA@AgNPs). BN hybrids were then introduced into PA6 to prepare thermally conductive PA6 composites. The results demonstrated that PA6/BN hybrids (PMB) composites exhibited higher thermal conducivity compared with PA6/BN composites, which revealed more effective construction of thermal conductive network in the composites with the addition of 3-D structured fillers. The effects of BN hybrids with different loadings on thermal stability, mechanical property, as well as electrical resistance of the composites were also analyzed. Overall, the prepared PMB composites exhibited outstanding performance in thermal conductivity, thermal stability, mechanical property, while retaining good electrical insulating property, which showed a potential application in electronic packaging fields.

Normally, the effective dispersion of thermal conductive fillers is a prerequisite for ensuring thermally conductive networks formed in polymer composites. In this work, a facile method was provided by using cellulose to alter the distribution state of boron nitride (BN) for the preparation of high thermally conductive polylactic acid (PLA). After powder mixing and hot‐pressing process, the Cellulose@BN was located at the boundaries of PLA granules to form consecutive thermally conductive networks with more compact structure. Morphology observation and FTIR spectra confirmed that BN edges absorbed on the cellulose surface under the intermolecular hydrogen bond interaction between PLA and BN. At the BN content of 25 wt%, contrasted with traditional BN/PLA segregated polymer composites (SPCs), thermal conductivity coefficient of Cellulose@BN/PLA SPCs improved by 53.5% from 0.71 to 1.09 Wm−1 K−1. This enhancement could be attributed to the reason that the cellulose regulated stripe aggregation allowed the BN connect with each other more compact, thus a thermal conduction networks with reduced phonon scattering were formed.