Property enhancement of polybenzoxazine modified with monoanhydrides and dianhydrides

Abstract

In this research, the incorporation of either monoanhydrides or dianhydrides with polybenzoxazine (PBA-a) can improve both thermal and mechanical properties with different manner. The property enhancements of PBA-a by monoanhydrides and dianhydrides were systematically investigated and compared. The glass transition temperatures (Tg) of the alloys were in order of PBA-a:NTDA>PBA-a:PMDA>>PBA-a:NA>PBA-a:PA. Furthermore, the Tg of the alloys was observed to be higher than that of neat PBA-a owing to the crosslink density enhanced by the addition of anhydride. This greater crosslink density also results from additional ester linkage formation. The alloys display high decomposition temperature (Td) reported at 10 % weight loss up to 430 °C under nitrogen atmosphere and substantial enhancement in char yield at 800 °C with a value of up to 63 % by weight. Additionally, toughness of the alloy films has been significantly improved with an addition of both types of the anhydrides. The results of this work suggest effective methods to enhance thermal properties of the PBA-a with an incorporation of the dianhydrides, while monoanhydrides were required as a PBA-a modifiers for better mechanical properties.