Color-stable superabsorbent polymer composition

A method of manufacturing color-stable superabsorbent polymer particles comprising the steps of:

• (a) forming a monomer mixture comprising:
• (i) at least one monomer capable of forming a superabsorbent polymer,
• (ii) a crosslinking agent,
• (iii) an initiator system comprising a sulfinic acid derivative having a structure
• wherein M is hydrogen, an ammonium ion, or a monovalent or a divalent metal ion of groups Ia, IIa, IIb, IVa, and VIIb of the Periodic Table of the Elements;
• R1 is OH or NR4R5, wherein R4 and R5, independently, are H or C1-C6alkyl;
• R2 is H or an alkyl, alkenyl, cycloalkyl, or aryl group, optionally having 1-3 substituents independently selected from the group consisting of C1-C6alkyl, OH, O—C1-C6alkyl, halogen, and CF3;
• and
• R3 is COOM, SO3M, COR4, CONR4R5, or COOR4, wherein M, R4, and R5 are as defined above, or, if R2 is unsubstituted or unsubstituted aryl, R3 is H;
• and the salts thereof;
• or a mixture thereof;
• (iv) an optional photoinitiator, and
• (v) water;
• (b) polymerizing the monomer and the cross-linking agent in the monomer mixture to form a superabsorbent polymer hydrogel;
• (c) optionally subjecting the superabsorbent polymer hydrogel to a low dose of UV radiation;
• (d) comminuting the superabsorbent polymer hydrogel to provide superabsorbent hydrogel particles;
• and
• (e) drying the superabsorbent polymer hydrogel particles for a sufficient time at a sufficient temperature to provide the color-stable superabsorbent polymer particles.