Table 3.

Chemical recycling methods.

Chemical Agents	Reaction Conditions	Tensile Strength Retention	Ref.
Nearcritical and supercritical water	250–400 °C, 4–27 MPa, 1–30 min	90–98%	[81]
Water + benzyl alcohol	400 °C, 1 h	–	[79]
NaCl 1 dissolution	Electrochemical (4–25 mA)	80%	[46]
Hydrochloric acid in tetrahydrofuran	Room temp., 24 h	Similar to virgin fibers	[82]
AlCl3 2 + Acetic acid	180 °C, 6 h	97.77%	[83]
Ethylene glycol	180 °C, 4 h	95%	[84]
Supercritical 1-propanol with 1% KOH 3	330 °C, 1 h	94.6%	[85]
Sub- and supercritical water and water/ethanol (50:50)	350–400 °C, 25 MPa	Similar to desized virgin fibers	[86]
ZnCl2/KOH/HPW 4/MgCl2 5/AlCl3/FeCl3 6 + ethanol/water	80–250 °C, 2–10 h	–	[87]
Water/acetone (20:80)	320 °C, 60 min	>90%	[88]
Supercritical n-butanol	360 °C, 1 h	98.63%	[89]
Supercritical acetone	320 °C, 20 min	Negligible decrease	[90]
Subcritical water Supercritical water	400 °C, 15 min 280 °C, 30 min	>90%	[91]
Peracetic acid (acetic acid + H2O2 7)	65 °C, 4 h	Similar to virgin fibers	[48]
Nearcritical water and supercritical acetone	260–300 °C, 6–30 MPa	Similar to virgin fibers	[92]
Superheated and supercritical acetone	350 °C, 2–14 MPa, 60 min	–	[93]
Benzyltrimethylammonium bromide (BTAB) and sodium dodecyl sulfate (SDS)	Process: 100 °C, 1 hDry: 100 °C, 24 h	96.9%	[94]

¹ Sodium chloride; ² Aluminium chloride; ³ Potassium hydroxide; ⁴ Phosphotungstic acid; ⁵ Magnesium chloride; ⁶ Ferric chloride; ⁷ Hydrogen peroxide.