Thermal conductivity enhancement of PLA/TPU/BN composites by controlling BN distribution and annealing treatment

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.

3D Thermal Network Supported by CF Felt for Improving the Thermal Performance of CF/C/Epoxy Composites

“…The method of adding fillers is a fast way to improve the thermal conductivity of polymers. Metal materials (such as copper powder [ 7 , 8 , 9 ], silver powder [ 10 , 11 ], metal sheet and wire [ 12 , 13 , 14 ]), carbon materials (such as carbon fiber (CF) [ 15 , 16 , 17 ], graphene material [ 18 , 19 ], graphite material [ 20 , 21 ], carbon nanotubes [ 22 , 23 ], carbon black [ 24 , 25 ]), inorganic fillers (such as aluminum nitride [ 26 , 27 ], boron nitride [ 28 , 29 , 30 ], silicon nitride [ 31 , 32 ], silicon carbide [ 33 ], alumina [ 34 , 35 ]) and other high thermal conductivity fillers are often used to improve the thermal conductivity of polymers. When the particulate filler content is small, it is difficult to significantly improve the thermal conductivity of the matrix.…”

Performance evaluation on particle‐reinforced rigid/flexible composites via fused deposition modeling3Dprinting

“…This was consistent with Mr. Shen's observations. 7 Moreover, similar to the effect of hBN particles, the addition of OMMT also made the fracture surface of its composites even rougher, especially PLA/TPU/OMMT samples. These rough texture characteristics indicated that there was still a phase separation phenomenon between the two matrics in the composite system.…”

“…The decomposition temperature of PLA was concentrated in the range of 330-380 C, of which 370 C was the fastest decomposition temperature. 17 Relatively speaking, the decomposition range of TPU was wide, and the main decomposition temperature range was around 400 C. 7,28 The addition of OMMT increased the decomposition rate of PLA and TPU. When PLA and TPU were blended, their molecular chains were complicatedly interlaced, which promoted the deterioration of the thermal stability of composites.…”

“…The thermal stability of PLA and TPU and their composites are investigated, as shown in Figure 4. Both PLA and TPU are oxygen-containing polymers, and they begin to thermally decompose slowly at 250 C. 7 Therefore, the change of DTG curve was concerned from 200 C. The molecular structure of PLA was more regular and single than that of TPU. The decomposition temperature of PLA was concentrated in the range of 330-380 C, of which 370 C was the fastest decomposition temperature.…”

“…5 At the same time, in addition to the matrix blending, the research on particle-reinforced 3D printed composites has also attracted much attention. For example, Zhang et al 6 researched the high-thermal conductive hexagonal boron nitride (hBN) 7 filled TPU composites by FDM 3D printing technique. Li et al 8 studied the thermal, mechanical, and electrical properties of FDM 3D printed PLA/CNT composites.…”