Preparation of Low-k Poly(dicyclopentadiene) nanocomposites with excellent comprehensive properties by adding larger POSS

Abstract

Low dielectric constant (low-k) polymer nanocomposites with good comprehensive properties are essential for microelectronics and wireless communication industry. Although extensive studies show that incorporation of polyhedral oligomeric silsesquioxane (POSS) is an effective strategy to realize this purpose, nearly all of them are based on T8 POSS and the influence of larger POSSs (i.e., T10 and T12 POSS) on polymer’s properties remains unclear. Herein three vinyl POSSs (T8V8, T10V10, and T12V12) with increased sizes were introduced into poly(dicyclopentadiene) (PDCPD) for preparation of high-performance low-k nanocomposites. Because these three POSSs are soluble in dicyclopentadiene monomer, a series of nanocomposites with molecular scale POSS dispersion were achieved after thermo-crosslinking. The results show that the k value of PDCPD can be decreased not only by increasing the content of these three POSSs but also by altering the POSS size. Consequently, the k value of PDCPD at 1 kHz was found to be reduced from 2.54 to 2.10 by adding high content of larger POSS (i.e., 7 wt% of T12V12) without damaging its inherent low dielectric loss. This result highlights the rule of POSS size and POSS content on the dielectric properties and could be used to predicate ultralow-k polymer nanocomposites by extrapolating to larger POSS and higher POSS content. Meanwhile, the comprehensive properties of PDCPD such as glass transition temperature, dimensional stability, mechanical properties, and hydrophobicity, are able to be enhanced by altering the POSS size and increasing the POSS content, making these resulting nanocomposites become useful materials for future microelectronic industry.