Significant improvement of thermal conductivities for BNNS/PVA composite films via electrospinning followed by hot-pressing technology. (15th October 2019)

• Record Type: Journal Article
• Authors: Yang, Xutong; Guo, Yongqiang; Han, Yixin; Li, Ying; Ma, Tengbo; Chen, Minjiao; Kong, Jie; Zhu, Jiahua; Gu, Junwei
• Is Part Of: Composites. Number 175(2019)
• Publication Date: 2019-10-15
• Subjects: Polyvinyl alcohol -- Boron nitride nanosheets -- Electrospinning -- Thermally conductive composite films; Composite materials -- Periodicals; Materials science -- Periodicals; Composite materials; Periodicals; Electronic journals; 620.118
• DOI: 10.1016/j.compositesb.2019.107070
• Languages: English
• ISSNs: 1359-8368

Abstract

Abstract: Research and development on polymer composites with high thermal conductivities and ideal thermal stabilities have become one of the hot topics in functional composites. In this work, boron nitride nanosheets/polyvinyl alcohol (BNNS/PVA) thermally conductive composite films were respectively prepared from ball milling (BNNS/PVA-I), directional freeze-drying (BNNS/PVA-II) and electrospinning technology (BNNS/PVA-III), followed by hot-pressing method. BNNS/PVA-III thermally conductive composite films had better comprehensive properties than that of BNNS/PVA-(I-II) composite films. Thermal conductivity coefficient in vertical direction ( λ ⊥ ) of the BNNS/PVA-III composite films with 30 wt% BNNS was 1.031 W/mK, obviously higher than that of BNNS/PVA-I ( λ ⊥ of 0.573 W/mK) and BNNS/PVA-II ( λ ⊥ of 0.694 W/mK), respectively. And the λ in parallel direction ( λ ∥ ) was significantly enhanced to 18.630 W/mK, increased by 3101.0% and 1437.1% compared to that of BNNS/PVA-I ( λ ∥ of 0.582 W/mK) and BNNS/PVA-II ( λ ∥ of 1.212 W/mK), respectively. Meantime, the glass transition temperature ( T g ) and heat-resistance index ( T HRI ) of the BNNS/PVA-III thermally conductive composite films with 30 wt% BNNS was 42.7 °C and 144.5 °C, 7.0 °C and 1.9 °C higher than that of pure PVA matrix, respectively.