Table 2. Epoxy group content according to the amount of hydrogen peroxide (34.5 wt%) and formic acid (85 wt%) used during the synthesis of LENR-1–5

Liquid rubber	Hydrogen peroxide feed contents (mol)	Formic acid feed contents (mol)	Epoxy group contents (%)
LENR-1	0.45	0.15	2.9
LENR-2	0.68	0.23	3.8
LENR-3	0.90	0.30	7.4
LENR-4	1.13	0.38	9.9
LENR-5	1.35	0.45	14.5