Liquid Crystal Functionalized Boron Nitride Fillers/Liquid Crystal Epoxy Thermally Conductive Composites

doi:10.19894/j.issn.1000-0518.210146

Chinese Journal of Applied Chemistry ›› 2021, Vol. 38 ›› Issue (10): 1382-1388.DOI: 10.19894/j.issn.1000-0518.210146

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Liquid Crystal Functionalized Boron Nitride Fillers/Liquid Crystal Epoxy Thermally Conductive Composites

Jun-Wei GU¹^,²(), Bei CHENG¹^,², Xu-Tong YANG¹^,²

¹Research & Development Institute of Northwestern Polytechnical University in Shenzhen，Shenzhen 518057，China
²School of Chemistry and Chemical Engineering，Northwestern Polytechnical University，Xi'an 710072，China

Received:2021-03-26 Accepted:2021-06-07 Published:2021-10-01 Online:2021-10-15
Contact: Jun-Wei GU
Supported by:
Guangdong Basic and Applied Basic Research Foundation(2019B1515120093);the National Natural Science Foundation of China(51773169);the Natural Science Basic Research Plan for Distinguished Young Scholars in Shaanxi Province(2019JC?11);the College Students' Innovative Entrepreneurial Training Plan Program(S202010699003)

Abstract

Abstract:

The thermal conductivity coefficient （λ） of thermally conductive polymer composites is difficult to reach the expected value due to the intrinsic low λ value ofpolymer matrix. Meanwhile， the interfacial thermal resistance between thermally conductive fillers and polymer matrix is also another important factor leading to the poor thermal conductivity. In this work， liquid crystal epoxy molecules are in?situ grafted on globular boron nitride （LCE-g-（GBN-100）， gGBN-100） fillers， which are melt-blended with main-chain liquid crystal epoxy resin （M-LCER） to fabricate the gGBN-100/M-LCER thermally conductive composites. Results show that the introduction of LCE on the surface of GBN-100 endows the liquid crystal properties of gGBN-100 fillers， and effectively reduces the interfacial thermal resistance between gGBN-100 fillers and M-LCER matrix. When the mass fraction of gGBN-100 fillers is 30%， the λ of gGBN-100/M-LCER thermally conductive composites is 1.12 W/mK， which is 2.2 times of that of pure M-LCER matrix （λ of 0.51 W/mK） and also higher than those of 30% GBN-100/M-LCER thermally conductive composites （λ of 1.02 W/mK）. At this time， the corresponding elastic modulus and hardness of gGBN-100/M-LCER composites increase from 2.78 GPa and 0.19 GPa to 4.13 GPa and 0.24 GPa， respectively.

Key words: Liquid crystal epoxy, Liquid crystal functionalization, Globular boron nitride fillers, Thermally conductive composites, Interfacial thermal resistance

CLC Number:

O632.7

Jun-Wei GU, Bei CHENG, Xu-Tong YANG. Liquid Crystal Functionalized Boron Nitride Fillers/Liquid Crystal Epoxy Thermally Conductive Composites[J]. Chinese Journal of Applied Chemistry, 2021, 38(10): 1382-1388.

Figures/Tables 7

Fig.1 Schematic diagram of in situ grafting LCE on GBN-100 （gGBN-100） fillers

Fig.2 1H NMR spectrum （A） and TGA curves （B） of gGBN-100 fillers

Fig.3 SEM images （A—B） of gGBN-100 and the corresponding element mapping （C—F）

Fig.4 DSC curves and POM image （A）， XRD patterns （B） of GBN-100 and gGBN-100 fillers

Fig.5 λ（A）and α（B）values of the thermally conductive gGBN-100/M-LCER composites

Fig.6 Schematic diagram of the thermally conductive mechanism for GBN-100/M-LCER （A） and gGBN-100/M-LCER （B） composites

Fig.7 Representative load-displacements curves （A）， elasticity modulus and hardness （B） of the thermally conductive gGBN-100/M-LCER composites

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Liquid Crystal Functionalized Boron Nitride Fillers/Liquid Crystal Epoxy Thermally Conductive Composites

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