A research on benzoxazine/cyanate ester/epoxy POSS nanocomposite with low dielectric constant and improved toughness

The matrix's dielectric constant can be reduced with little quantity of POSS because of its unique cage skeleton structure and remained air in the caves. After epoxied, epoxy polyhedral oligomeric silsesquioxane (EPPOSS) promoted its compatibility with bisphenol A cyanate ester (BADCy) and bisphenol A benzoxazine (BA-a) by a curing processing between BADCy and EPPOSS and further copolymerizing with ring opened BA-a. Consequently, two T(g)s were observed in the integrated nanocomposite, attributing to the BADCy homopolymer and the BADCy and BA-a copolymer. The more quantity of EPPOSS, the lower dielectric constants of nanocomposites achieved, as well as the initial storage modulus and T(g)s due to the flexible ether bonds generated by EPPOSS. With up to 15 wt.% EPPOSS, the dielectric constant decreased to 2.72 at 1 MHz. The toughness and thermal stability of the nanocomposites also enhanced through increased the crosslinking density and inorganic Si-O-Si framework of EPPOSS.

Automated summary

The dielectric constant of the matrix can be reduced by adding a small amount of POSS due to its unique cage skeleton structure and the air trapped in the caves. The compatibility between EPPOSS and BADCy as well as BA-a was enhanced through curing processing and copolymerizing. The addition of higher quantities of EPPOSS resulted in lower dielectric constants, improved storage modulus, and T(g)s, as well as increased toughness and thermal stability through increased crosslinking density and inorganic Si-O-Si framework.