Jun Zhao,Ziliang Rui,Zhiwei Hu,Zhen Shangguan,Shuai Yin,Hao Peng
In battery thermal management (BTM), flexible phase change materials (FPCMs) emerge as highly promising substances, owing to their simple installment and low contact thermal resistance. However, FPCMs based on high thermal conductivity fillers and polymers always suffer from the enduring challenges of poor high-temperature resistance and poor filler-matrix compatibility. To solve these problems, a novel strategy is reported in this work, wherein FPCMs with excellent filler-matrix compatibility and satisfactory high-temperature resistance are synthesized by two steps: functionalizing the hexagonal boron nitride (hBN) surface and inducing the inter crosslinking between Styrene-Butadiene-Styrene(SBS) and Low-density polyethylene(LDPE). Vinyltrimethoxysilane (VTMS) molecules were introduced on the surface of raw hBN by hydroxylation and silanization surface modification to improve the compatibility of hBN with the matrix. Concluding from the results, the addition of 6.7 wt% LDPE doubled the high-temperature resistance of FPCMs, enabling them to maintain their structural integrity even at 200 °C for 1 h. The prepared FPCMs also exhibited higher thermal conductivity (increased by 20.5 %), low leakage rate (<0.6 wt% after 70 heating–cooling cycles), high enthalpy (122 J g −1 ), and strong adhesion (>0.1 MPa), etc. In terms of BTM performance, the FPCMs-based passive cooling BTM presents remarkable temperature control capabilities (maximum temperature reduction by 16.3 ℃) and uniform temperature performance (maximum temperature difference < 2.5 ℃). Collectively, this work will provide a promising approach for the fabrication of high-performance FPCMs in BTM and other thermal management applications for electronic devices.
Liu Shujuan,Liu Lijuan,Yang Kangli,Yuan Zhiqing,Li Xinyi,Li Cancheng,Meng Shoutong
In order to improve the environmental problems caused by the extensive use of plastics, this paper introduced a new strategy to add and modify the physical structure, which could not only reduce the use of plastics, but also improve the mechanical properties of bamboo plastic composites. In this work, the bamboo-woven structure was introduced into the bamboo fiber/low density polyethylene (LDPE) composites to enhance the mechanical properties. Besides, to enhance the interfacial compatibility, maleic anhydride (MA) and polyvinyl alcohol (PVA) were used to modify LDPE and bamboo-woven structure, respectively. The mechanical properties of the prepared PVA-bamboo-woven structure/bamboo fiber/MA-LDPE composites were greatly improved. The bamboo plastic composites were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, water contact angle (WCA) test and mechanical property test. The results showed that the bamboo-woven structure/bamboo fiber/MA-LDPE composite has superior properties at 45% bamboo fiber content. The tensile strength reached to 33.842 MPa, which was increased by 65.01% compared to the bamboo fiber/MA-LDPE composites, and the bending strength reached to 36.6585 MPa increased by 81.46% in relation to the bamboo fiber/MA-LDPE composites. In addition, even a large number of hydrophilic bamboo fibers and bamboo-woven structure were carried by the composites, a good hydrophobicity was still maintained and the WCA reached to 93.71°. The composites with excellent mechanical properties and hydrophobicity provided a reference for the use of bamboo fibers in environmentally friendly packaging materials.
危险品化学品经营许可证（带存储）