Ambient-Dried, Ultra-high Strength, Low Thermal Conductivity, High Char Residual Rate F-type Polybenzoxazine Aerogel

Guoqiang Qin; Shilun Jiang; Haotian Zhang; Shengjian Qin; Hongya Wu; Feipeng Zhang; Guanglei Zhang

doi:10.1021/acsomega.2c01300

Ambient-Dried, Ultra-high Strength, Low Thermal Conductivity, High Char Residual Rate F-type Polybenzoxazine Aerogel

ACS Omega. 2022 Jul 18;7(30):26116-26122. doi: 10.1021/acsomega.2c01300. eCollection 2022 Aug 2.

Authors

Guoqiang Qin^{1

2}, Shilun Jiang^{1

2}, Haotian Zhang^{1

2}, Shengjian Qin^{1

2}, Hongya Wu^{1

2}, Feipeng Zhang³, Guanglei Zhang^{1

2}

Affiliations

¹ School of Materials Science and Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.
² Hebei Provincial Engineering Research Center of Metamaterials and Micro-device, Shijiazhuang 050043, China.
³ Institute of Sciences, Henan University of Urban Construction, Pingdingshan 467036, P. R.China.

Abstract

The effect of the curing temperature (T _c) on the properties of PBO aerogel was investigated in this paper. The compressive strength of PBO aerogel prepared was much higher than that of PBO aerogel of the same density in other kinds of literature. With the robust F-type polybenzoxazine (PBO) aerogels with ultra-high Young's modulus (733.7 MPa at 0.48 g/cm³ and 1070 MPa at 0.57 g/cm³), excellent properties were obtained through a facile and scalable room-temperature HCl-catalyzed sol-gel method, followed by the ambient pressure drying technique. It is found that T _c plays a vital role in the polymerization process and the evolution of the microstructure of the 3D porous PBO network, where the necks between the nanoparticles become thick and strong when T _c is up to 150 °C, resulting in a pearl necklace-to-worm transformation in the micro-structure and significant growth in mechanical properties, but if T _c is higher than 180 °C, the pore volume and specific surface area will decrease sharply. Moreover, all synthetic PBO aerogels here possessed inherent flame retardancy and a high residual char rate in the volume density (0.32-0.57 g/cm³). These properties make the F-type PBO aerogels a candidate material in aerospace applications or other fields.