Thermal Stability, Mechanical Properties and Ceramization Mechanism of Epoxy Resin/Kaolin/Quartz Fiber Ceramifiable Composites

Abstract

The application of epoxy resins in high temperature and thermal protection fields is limited due to their low decomposition temperature and low carbon residual rate. In this paper, epoxy resin (EP)/quartz fiber (QF) ceramifiable composites were prepared using a prepreg-molding process. The thermal stability, phase change and mechanical properties after high-temperature static ablation and ceramization mechanism of EP/QF ceramifiable composites were investigated. The addition of glass frits and kaolinite ceramic filler dramatically increases the thermal stability of the composites, according to thermogravimetric (TG) studies. The composite has a maximum residual weight of 61.08%. The X-ray diffraction (XRD) results show that the mullite ceramic phase is generated, and a strong quartz diffraction peak appears at 1000 °C. The scanning electron microscope (SEM) and element distribution analyses reveal that the ceramic phase generated inside the material, when the temperature reaches 1000 °C, effectively fills the voids in composites. The composites have a bending strength of 175.37 MPa at room temperature and retain a maximum bending strength of 12.89 MPa after 1000 °C treatment.

A Novel Fused SiO2 and h-BN Modified Quartz Fiber/Benzoxazine Resin Ceramizable Composite with Excellent Flexural Strength and Ablation Resistance

“…Therefore, the addition of fused silica and an appropriate amount of h-BN can improve the bearing capacity of the composites. Notably, the flexural strength of the composites described in this work was much higher than those reported in previous works [14,27].…”

“…Therefore, they are only applied in local ultra-high-temperature parts, such as the nose tip, sharp leading edge of the body, and inlet of the engine, but fail to provide large-area thermal protection for hypersonic vehicles [3,8]. Ablation-type TPMs dissipate heat by sacrificing themselves (such as pyrolysis, melting, sublimation, and other physical and chemical reactions) and lose part of their own mass [5,14]. They are the most widely used TPM thermal protection materials, especially for missiles and spacecraft.…”

Thermal, chemical and physical analysis of VDW.1Seal, Fill Root ST, and ADseal root canal sealers

“…The decomposition of the tested sealers started at 145 °C, 135 °C and 91 °C for VDW.1Seal, ADseal sealer, and Fill Root ST, respectively. This can be primarily explained based on the XRD analysis that revealed a higher degree of crystallinity (73% and 74%) for VDW.1Seal and ADseal, respectively, as well as their inclusion of the stable zirconium oxide ceramic fillers, which resist thermal decomposition up to 2000 ºC 28 , 29 , in comparison with the Fill Root ST whose crystallinity was only 67%.…”

Investigation of Dielectric, Mechanical, and Thermal Properties of Epoxy Composites Embedded with Quartz Fibers

“…Dielectric characteristics can significantly and directly impact the performance of electronic devices by resistancecapacitance (RC) delay and crosstalk noise [11]. Stable dielectric materials are characterized by minimal variation in E r , a low δ, high breakdown strength [12], and mechanical and thermal stability [13]. Equation (2) indicates the relationship between the signal delay time and the losses which is:…”

“…Extensive research has been carried out to investigate the properties of fiber-reinforced composites [12]. Selecting the most suitable reinforcing fibers [34] and polymer matrix [35] is beneficial to obtaining polymer fiber-reinforced composites for radome applications [36].…”