Zheng Liu, Xiaoli Fan, Junliang Zhang, Lixin Chen, Yusheng Tang*, Jie Kong and Junwei Gu*. PBO fibers/ fluorine-containing liquid crystal compound modified cyanate ester wave-transparent laminated composites with excellent mechanical and flame retardance properties. Journal of Materials Science & Technology, 2023, 152: 16-29. 2021IF=10.319.（1區材料科學Top期刊，中國科技期刊卓越行動計劃-重點類期刊項目，2021中國最具國際影響力學術期刊）
https://doi.org/10.1016/j.jmst.2023.01.007
Abstract
Bisphenol A dicyanate ester resins modified by fluorine-containing liquid crystal compound (LCFE) are applied as polymer matrix (LCFE-BADCy), poly(p-phenylene-2,6-benzobisoxazole) (PBO) fibers as reinforcements, and fluorine/adamantane PBO precursor (preFABPBO) as interfacial compatibilizer to prepare the corresponding PBO fibers/FABPBO/LCFE-BADCy wave-transparent laminated composites. LCFE could improve the order degree of BADCy cured network, in favor of enhancing the wave-transparent performance, mechanical properties, and intrinsic thermal conductivity. The dielectric constant and dielectric loss of PBO fibers/FABPBO/LCFE-BADCy composites are highly temperature (25~200oC) and frequency (104~107 Hz and 8.2~12.4 GHz) stable with the value of 2.49 and 0.003 under 106 Hz at 25oC, and the corresponding wave transmission efficiency is 95.0%, higher than that of 92.5% for PBO fibers/BADCy composites. The interlamellar shear strength and flexural strength are respectively 50.7 MPa and 682.5 MPa, 38.1% and 16.2% higher than those of PBO fibers/BADCy composites. Besides, the volume resistivity, breakdown voltage, heat resistance index, glass transition temperature, flame retardant grade, and ultimate oxygen index of PBO fibers/FABPBO/LCFE-BADCy composites are respectively 5.3×1015 Ω·cm, 29.75 kV/mm, 217.2oC, 245.7oC, V-1 grade, and 33.6%, expected to be performed as a new generation of “light weight/loading/wave-transparent” electromagnetic window materials in advanced military weapons and civil communication base station.
以含氟液晶環氧化合物（LCFE）改性的雙酚A氰酸酯（LCFE-BADCy）樹脂為基體、聚對苯撐苯并二噁唑（PBO）纖維為增強體、含氟金剛烷PBO前驅體（preFABPBO）為界面相容劑，經高溫模壓制備PBO纖維/FABPBO/LCFE-BADCy層壓透波復合材料。LCFE的引入提升了BADCy樹脂固化網絡的有序性，同步提升了LCFE-BADCy樹脂的透波性能、力學性能和本體導熱性能。PBO纖維/FABPBO/LCFE-BADCy層壓透波復合材料的介電常數和介電損耗角正切值分別為2.49和0.003（106 Hz，25oC），相應的理論透波率為95.0%，高于PBO纖維/BADCy（92.5%），在較寬溫度（25~200oC）和頻率范圍內（104~107 Hz和8.2~12.4 GHz）均具有優異穩定性；且在高頻段下具有較低的插入相位移，能夠保證電磁信號的高效和高保真傳輸；其層間剪切強度（ILSS）和彎曲強度分別為50.7 MPa和682.5 MPa，較PBO纖維/BADCy的36.7 MPa和587.4 MPa分別提升了38.1%和16.2%。PBO纖維/FABPBO/LCFE-BADCy層壓透波復合材料的體積電阻率、擊穿電壓、耐熱指數、玻璃化轉變溫度、阻燃等級和極限氧指數分別為5.3×1015 Ω·cm、29.75 kV/mm、217.2oC、245.7oC、V-1級和33.6%。本文制備的層壓復合材料兼具優異的透波性能、力學性能、絕緣性能、耐熱性能、耐環境老化性能和阻燃性能，有望作為新一代“輕量/承載/透波”一體化電磁窗口材料在新型軍用武器裝備和民用通信基站獲得更廣泛的應用。
論文亮點
1. LCFE的共聚引入提升了BADCy樹脂固化網絡的有序性，同步提升了LCFE-BADCy樹脂的透波性能、力學性能和本體導熱性能。
2. PBO纖維/FABPBO/LCFE-BADCy層壓透波復合材料的理論透波率達95.0%，明顯優于PBO纖維/BADCy的92.5%，且具有優異溫度和頻率穩定性。
3. PBO纖維/FABPBO/LCFE-BADCy層壓透波復合材料的ILSS和彎曲強度較PBO纖維/BADCy的ILSS（36.7 MPa）和彎曲強度（587.4 MPa）分別提升了38.1%和16.2%。
4. PBO纖維/FABPBO/LCFE-BADCy層壓透波復合材料的體積電阻率、擊穿電壓、耐熱指數、玻璃化轉變溫度、阻燃等級和極限氧指數分別為5.3×1015 Ω·cm、29.75 kV/mm、217.2oC、245.7oC、V-1級和33.6%。