The invention provides a method for synthesizing an end-amino
epoxy resin
toughening type curing agent, and aims at solving the technical problems of effectively improving the
toughness and the
impact strength of a
resin casting body and composites thereof. The method particularly comprises the steps that 2 mol of
aromatic diamine containing
ether bonds is added into a three-neck flask,
nitrogen is fed, and stirring at
room temperature is conducted till the
aromatic diamine containing the
ether bonds is completely dissolved in
organic solvent; 1 mol of aromatic dianhydride is added, the temperature is controlled to be 30 DEG C, and stirring is conducted for five hours to obtain yellowish transparent liquid; the yellowish transparent liquid is dropwise added to deionized water, stirring is conducted to obtain white turbid suspension, washing and suction
filtration are conducted, and a white
filter cake, namely, the end-amino
epoxy resin
toughening type curing agent, is obtained. According to the method for synthesizing the end-amino
epoxy resin
toughening type curing agent, the synthesis technology is simple, and operation is convenient; the
aromatic diamine containing the
ether bonds and the aromatic dianhydride are adopted to synthesize end-amino
polyamide acid on the condition that the
molar ratio is two to one; due to the fact that amido of the end-amino
polyamide acid can conduct the prepolymerization reaction with epoxy groups of epoxy resin, the
polyamide acid is introduced to the molecular structure of the epoxy resin, the toughening effect is achieved, and the
impact strength of the composites is increased by 20 percent.