A method of reacting a toluenesulfonyl-terminated polyoxyethylene compound having the formula CH3—C6H4—SO2—(O—CH2—CH2)n—O—R1 with an ammonium salt having the formula NR24X to form a compound having the formula X—CH2—CH2—(O—CH2—CH2)n-1—R3. The value n is a positive integer. X is a halogen, cyanide, cyanate, thiocyanate, or azide. R1 is a terminating group. Each R2 is hydrogen or an alkyl group. —R3 is —O—R1 or —X.