[Composites Part A] Improving the comprehensive properties of PBO fibres/cyanate ester composites using a hyperbranched fluorine and epoxy containing PBO precursor
writer：Zheng Liu, Xiaoli Fan, Junliang Zhang*, Zhiyong Yang, Yusheng Tang, Jianwei Li, Jie Kong and Junwei
keywords：Polymer matrix wave-transparent composites
source：期刊
specific source：Composites Part A
Issue time：2021年
Hyperbranched fluorine and epoxy containing PBO precursor (epoxy-preFHBPBO) was synthesized and utilized as interface compatibilizer to synchronously improve the mechanical and dielectric properties of poly(p-phenylene-2, 6-benzobisoxazole) (PBO) fibres reinforced bisphenol A dicyanate ester (BADCy) resins (PBO fibres/FHBPBO-co-BADCy) laminated composites. 1H NMR, 13C NMR, and FTIR analyses confirmed the successful preparation of epoxy-preFHBPBO. The introduction of hyperbranched structure and fluorine groups significantly improved the mechanical properties and wave-transparent performance. Compared with PBO fibres/BADCy, the flexural strength and interlaminar shear strength of PBO fibres/FHBPBO-co-BADCy composites with 7 wt.% epoxy-preFHBPBO were respectively enhanced to 634.9 and 46.9 MPa, increased by 8.1% and 27.8%. The corresponding dielectric constant and dielectric loss were 2.65 and 0.003, respectively, lower than those of PBO fibres/BADCy (3.06 and 0.006) composites. Meanwhile, the corresponding volume resistivity and breakdown strength were 4.93×1015 Ω?cm and 25.38 kV/mm, higher than PBO fibres/BADCy resins composites (2.2×1015 Ω?cm and 17.69 kV/mm).
以縮聚和端基修飾制備得到的環(huán)氧端基含氟超支化PBO前驅(qū)體（epoxy-preFHBPBO）為界面相容劑，經(jīng)高溫模壓制備PBO纖維/FHBPBO-co-BADCy層壓透波復(fù)合材料。FTIR、1H NMR和13C NMR證明成功制備出具有預(yù)期分子結(jié)構(gòu)的epoxy-preFHBPBO。超支化拓?fù)浣Y(jié)構(gòu)和含氟基團(tuán)的引入能夠顯著改善BADCy樹(shù)脂的力學(xué)性能和介電性能。當(dāng)epoxy-preFHBPBO的用量為7 wt%時(shí)，PBO纖維/FHBPBO-co-BADCy層壓透波復(fù)合材料的彎曲強(qiáng)度和層間剪切強(qiáng)度分別從PBO纖維/BADCy的587.4 MPa和36.7 MPa提升至634.9 MPa和46.9 MPa，分別提升了8.1%和27.8%；1 MHz下PBO纖維/FHBPBO-co-BADCy的介電常數(shù)和介電損耗角正切值分別為2.65和0.003，低于PBO纖維/BADCy層壓透波復(fù)合材料的ε和tanδ（3.06和0.006）。PBO纖維/FHBPBO-co-BADCy層壓透波復(fù)合材料的體積電阻率和擊穿電壓值分別為4.93×1015 Ω?cm和25.38 kV/mm，高于PBO纖維/BADCy層壓透波復(fù)合材料（2.2×1015 Ω?cm and 17.69 kV/mm）。