Fabrication and investigations on the polydopamine/KH-560 functionalized PBO fibers/cyanate ester wave-transparent composites

Functionalized poly (p-phenylene-2, 6-benzobisoxazole) (f-PBO) fibers were firstly obtained by introducing polydopamine (PDA) and 3-GlycidoxypropyltriMethoxysilane (KH-560), then performed to fabricate the f-PBO fibers/fluoride-containing bisphenol A dicyanate ester (m-BADCy) wave-transparent laminated composites. PDA was coated on the surface of PBO fibers and KH-560 was also grafted onto the PBO fibers. And the single fiber pull-out strength of the f-PBO fibers/m-BADCy micro-composites was increased from 3.2 MPa (PBO fibers/BADCy) to 4.0 MPa. Interlaminar shear strength (ILSS) and flexural strength of the f-PBO fibers/m-BADCy composites was also enhanced to 49.5 MPa and 652.2 MPa, increased by 39.8% and 12.1%, compared with that of PBO fibers/BADCy composites (ILSS of 35.4 MPa and flexural strength of 582.0 MPa), respectively. The corresponding ε and tanδ was decreased to 2.86 and 5.7 × 10^-3, declined by 6.5% and 23.0%, compared with that of PBO fibers/BADCy composites (ε of 3.06 and tanδ of 7.4 × 10^-3), respectively.