Preparation and Characterization of Fluorine-Containing Dianhydride-Modified Polybenzoxazine

Abstract

In this research, three types of fluorine-containing benzoxazine monomers i.e. BA-4fa, BAF-a and BAF-4fa are successfully prepared via solventless technology and their chemical functionality has been confirmed by fourier transform infrared spectroscopy (FTIR). Fluorine-containing polymer alloy films were fabricated by reacting bisphenol-AF/aniline based polybenzoxazine (PBAF-a) with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) in n,n-dimethylacetamide solvent. From the results, the alloy films show superior degradation temperature at 10% weight loss up to 464°C and significant enhancement in char yield at 800°C with a value up to 56% by weight due to the formation of ester linkage between hydroxyl group of the PBAF-a and the carbonyl group in the dianhydride resulting in a more flexibility in PBAF-a/6FDA. Moreover, glass transition temperature of the alloy films increase with increasing dianhydride content and exhibit a maximum value of 287°C at 2.5/1 PBAF-a/6FDA mole ratio. The incorporation of fluorine groups into polybenzoxazine is able to decrease dielectric constant of the resulting alloys. Additionally, the alloy films also provide a greater hydrophobicity behavior as evidently seen from a higher water contact angle with increasing amount of the 6FDA. Therefore, PBAF-a/6FDA alloy films are appropriate for an application as polymeric film for coating and high thermal resistant material.