The development of novel polymer dielectrics with enhanced dielectric performance is a great challenge for application of film capacitors in modern electronics and electrical systems. Herein, an innovative approach of chemical vapor deposition polymerization technology is proposed to prepare the all-organic sandwich structured parylene/polyimide/parylene (Py/PI/Py) composite films by employing poly(chloro-para-xylylene) (parylene C) as the outer layers and polyimide (PI) as the inner layer. The Py/PI/Py composites exhibit superior thermal resistance and outstanding mechanical properties. Moreover, thanks to the interfacial effect which contributes to reinforcing the dielectric response and the thickness effect which facilitates improving the breakdown strength, the dielectric performance of Py/PI/Py composites has been enhanced significantly. Accordingly, dielectric constant of 4.52–5.09, dissipation factor of 0.21–1.01%, and breakdown strength of 307–460 MV m −1 are achieved. Besides, notable energy storage performance is also obtained in Py/PI/Py composite dielectrics. Consequently, this novel application of chemical vapor deposition polymerization method in preparing all-organic multilayered polymer composite films with sandwich structure shows promising potential in film capacitor applications in harsh conditions.
Feipeng Wang,Jian Zhou,Linyang Dan,Yihua Qian,Shi Li,Issouf Fofana,Massimo Pompili,Jian Li
The oil-paper insulation system in eco-friendly fire-retardant transformers depends on hydrophilic natural ester insulating oil. Moisture within the system synergistically interacts with aging, worsening oil-paper insulation degradation and hastening overall system aging. Chemical vapor deposition was used to create parylene surface-modified insulating paper as a strategy to inhibit moisture-induced aging in natural ester oil-paper insulation. The effectiveness of the approach was identified by a comprehensive assessment of the physicochemical and electrical properties of the parylene surface-modified insulating paper. The findings from accelerated thermal aging at 130 °C for 90 days on the natural ester oil-paper insulation system reveal the outstanding lipophilic and hydrophobic properties while maintaining electrical characteristics of the parylene surface-modified insulating paper. After 90 days of aging, the parylene surface-modified insulating paper exhibited a 56.76 % higher degree of polymerization and a 19.36 % significantly lower moisture content than conventional cellulose insulating paper. In the natural ester oil-paper insulation system, the parylene surface-modified insulating paper led to a notable 63 % reduction in insulating oil acid value, a 60.50 % decrease in dielectric loss, and a substantial 20.35 % increase in AC breakdown voltage. Molecular-level investigations revealed the inhibitory mechanism of the parylene film, offering a promising solution to enhance the thermal stability and aging resistance of natural ester oil-paper insulation systems.
危险品化学品经营许可证（带存储）