acid [DPA, Saen
Chemical Technology (Shanghai) Co., Ltd.], 1,4-dibromo butane (DBB,
Shanghai Aladdin Biochemical Technology Co., Ltd.), N,N-dimethylformamide (DMF, Sinopharm Chemical Reagent
Co., Ltd.), potassium carbonate (K2CO3, Sinopharm
Chemical Reagent Co., Ltd.), acetone (Nanjing Chemical Reagent Co.,
Ltd.), ethyl acetate (Shanghai Titan Scientific Co., Ltd.), anhydrous
magnesium sulfate (MgSO4, Shanghai Macklin Biochemical
Co., Ltd.), epichlorohydrin (ECH, Shanghai Lingfeng Chemical Reagent
Co., Ltd.), benzyltriethylammonium chloride (TEBAC, Shanghai Aladdin
Biochemical Technology Co., Ltd.) sodium hydroxide (NaOH, Shanghai
Aladdin Biochemical Technology Co., Ltd.), calcium oxide (CaO, Sinopharm
Chemical Reagent Co., Ltd.), methyl tetrahydrophthalic anhydride (MTHPA,
Chengdu Ai Keda Chemical Reagent Co., Ltd.), 2,4,6-tris(dimethylaminomethyl)phenol
(TAP, Saen Chemical Technology (Shanghai) Co., Ltd.), and ethylene
glycol diglycidyl ether [EGDGE, epoxy value: 0.7 mol (100 g)−1, Shanghai Rin Technology Development Co., Ltd.] were used as received
without any further purification.