Improved properties of PTFE composites filled with glass fiber modified by sol–gel method

Abstract

Tetraethyl orthosilicate (TEOS) was used as the silicon source, and polydimethylsiloxane (PDMS) was the organic precursor to modify the surface of glass ber (GF) through the sol-gel method. The modi ed GF noted T-GF was lled in PTFE to prepare PTFE/T-GF composites. SEM, FTIR, XPS, and contact angle con rmed that organic-inorganic hybrids were successfully loaded on GF's surface. Compared with PTFE/GF and the conventional coupling agent modi ed GF lled PTFE composites, the properties of PTFE/T-GF composites, including dielectric properties, mechanical properties, moisture absorption, thermal conductivity, and coe cient of thermal expansion (CTE), enhanced signi cantly for the improvement of compatibility of PTFE and GF. Moreover, the PTFE/T-GF exhibited improved dielectric constant (2.305), decreased dielectric loss (9.08E -4 ), higher bending strength (21.45 MPa) and bending modulus (522 MPa), better thermal conductivity (0.268 W/m*K) and lower CTE (70 ppm/℃), making it has promising application as the substrate materials for printed circuit board.

All organic polymer dielectrics for high‐temperature energy storage from the classification of heat‐resistant insulation grades

“…Due the crystallinity up to 65%–70% and the strong attraction of fluorine atoms, the PTFE demonstrates excellent thermal resistance up to 260 °C and a low ε r (≈2.1), 99 along with an special low tan δ (0.01%). However, the low energy density caused by low ε r limits its application in capacitor films, while solid‐phase transition temperature around 325 °C further causes obstruction in melt‐processing PFTE into the industrially film level 100,101 …”

PTFE Crystal Growth in Composites: A Phase-Field Model Simulation Study

“…Polytetrafluoroethylene (PTFE) is considered an outstanding candidate for use as a dielectric medium for high-frequency devices [1] due to its excellent dielectric properties and stability versus frequency, and it can meet the pressing demand for the rapidly developing modern information industry [2]. Although PTFE has excellent dielectric properties at a high frequency, its high thermal expansion coefficient, low thermal conductivity, and poor mechanical properties limit its application in electronic devices [3].…”

“…Although PTFE has excellent dielectric properties at a high frequency, its high thermal expansion coefficient, low thermal conductivity, and poor mechanical properties limit its application in electronic devices [3]. These deficits could be overcome by making PTFE-based composites with fillers to modify the matrix's thermal, mechanical, and dielectric properties [2,[4][5][6]. Researchers are trying to design composites by predicting the properties of the composites.…”