Synthesis of novel maleimides having allyloxy groups and evaluation of the physical properties of the cured products

Abstract

Using aminophenols as starting materials, we synthesized maleimide resins with a unit structure having both an allyloxy group and a maleimide group on one aromatic ring through a multi-step synthesis process. These maleimide resins have a highly crystalline N-aryl type maleimide structure within the molecule. However, the allyloxy group gives them a low melting point and makes them amorphous, resulting in low melt viscosity, good solubility in solvents, and excellent processability. The glass transition temperature of the cured material exceeded 350℃, and thermogravimetric analysis showed high thermal decomposition resistance, confirming that the material possesses high levels of both physical and chemical heat resistance. During the curing reaction, in addition to the polymerization reaction of the maleimide group, a Claisen rearrangement reaction of the allyloxy group occurs, and it is expected that the reaction product will also react with the maleimide group. It has been suggested that the network structure formed by these reactions contributes to improving the mechanical strength of the cured material.