液晶聚芳酯(LCP)热稳定性好、可加工性强,介电性能优良,是应用于5G通讯的理想基板材料。从分子设计角度出发,在对羟基苯甲酸(HBA)和6-羟基-2-萘甲酸(HNA)的共聚体系中引入双酚A(BPA)和双酚芴(BHPF)两种低极性非线性单体进行熔融聚合,得到两种改性的液晶聚芳酯R-BPA和R-BHPF,以进一步改善其介电性能。系统研究了这两种双酚单体对液晶聚芳酯热性能、介电性能以及加工性的影响。结果表明:改性LCP均存在自增强的微纤结构,引入芴结构的聚芳酯具有更优异的耐热性,对介电性能的改善也更加显著。与HBA/HNA共聚体系相比,R-BHPF10的介电常数从3.38降低到了2.48(106Hz),介电损耗从0.013降低到6.1×10-3,有望在5G通讯领域得到广泛应用。
Liquid crystal polyarylate (LCP),with excellent thermal stability,outstanding processability and good dielectric properties,is a wonderful laminate material for 5G communication applications.Starting from the perspective of molecular structural design,two kinds of modified liquid crystal polyarylates,R-BPA and R-BHPF,were obtained by melt-polymerization through introducing two nonlinear monomers with low polarity,bisphenol A (BPA) and bisphenol fluorene (BHPF),into a copolymerization system of p-hydroxybenzoic acid (HBA) and 6-hydroxy-2-naphthalenecarboxylic acid (HNA),aiming to further improve their dielectric properties.The effects of these two bisphenol monomers on the thermal properties,dielectric properties and processabilities were systematically investigated.The results showed that both modified LCPs exhibited self-reinforcing microfibrillar structures,and the polyarylate with the introduction of fluorene structure had better heat-resistance and more significant improvement of dielectric properties.Compared with the HBA/HNA copolymerization system,the dielectric constant of R-BHPF10 reduced from 3.38 to 2.48 at 106Hz frequency and the dielectric loss reduced from 0.013 to 6.1×10-3,indicating great potential for widespread application in the field of 5G communication.
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基金资助
国家重点研发计划项目(2021YFB3700105);国家自然科学基金(52402102)
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