Chemically decomposable thermosetting resin composition for recycling fiber-reinforced composite and dissolving method thereof

A chemically decomposable thermosetting resin composition, comprising:

• an epoxy resin;
• a multifunctional glycidyl-ester-based compound;
• an additive having a hydroxyl group on at least one of terminals of a main chain thereof, the additive being at least one selected from the group consisting of compounds represented by Chemical Formulas 2 to 4 below;
• and
• an acid-anhydride-based curing agent,
• wherein the thermosetting resin composition comprises, based on 100 wt % of a total amount thereof excluding the curing agent, 1 to 98 wt % of the epoxy resin, 1 to 98 wt % of the multifunctional glycidyl-ester-based compound, and 1 to 30 wt % of the additive having a hydroxyl group on at least one of terminals of the main chain thereof:
• (in Chemical Formula 2,
• n is 0 or 1;
• R1 is hydrogen or a linear or branched C1-5 alkyl;
• and
• R2s are each independently
• and the same as or different from each other, wherein u is 0 to 330, v is 0 to 430, both u and v are not zero, and repeating units
• in parentheses are randomly arranged);
• (in Chemical Formula 3,
• R3 is hydrogen, a linear or branched C1-5 alkyl, cycloalkane having 5 to 10 atoms, benzene or naphthalene;
• r is 1 to 6;
• p is 0 to 430, q is 0 to 330, and both p and q are not zero;
• repeating units
• in parentheses are randomly arranged;
• and
• Chemical Formula 3 is configured such that R3 is substituted with
• (in Chemical Formula 4,
• R4 is a linear or branched C1-5 alkyl, cycloalkane having 5 to 10 atoms, benzene or naphthalene;
• s is 0 to 430;
• t is 1 to 6;
• and
• Chemical Formula 4 is configured such that R4 is substituted with