Polymer electrolyte membrane
Disclosed are a multi-block copolymer, its producing method and an electrolyte membrane using the same. The multi-block copolymer includes a hydrophobic block having a plurality of repeating units represented as chemical formula 1; and a hydrophilic block having a plurality of repeating units represented as chemical formula 2. The multi-block copolymer is acidified, and can be used to an electrolyte membrane and a fuel cell. The use of the multi-block copolymer as an electrolyte membrane ensures excellent dimensional stability.
1. A branched multi-block copolymer, comprising:
a hydrophobic block having a plurality of repeating units represented as chemical formula 1; and
a hydrophilic block having a plurality of repeating units represented as chemical formula 2,
wherein A, X and Y are each
independently,
R is —NO 2 or —CF 3 ,
Z is
Q is —SO 3 H, —SO 3 − M + , —COOH, —COO − M + , —PO 3 H 2 , —PO 3 H − M + or —PO 3 2− 2M + , and M is Na or K,
B is
G is X, and G′ is Z,
0<u/t<1, and 0<w/v<1,
0.7<(e+1.5*g)/(f+h)≦0.95 or 0.7<(f+h)/(e+1.5*g)≦0.95, and a+e+1.5(c+g)=f+h+b+d, in which a, b, c, d, e, f, g and h are molar ratios, and
the hydrophilic block has a total number of repeating units of 100 to 350.
2. A branched multi-block copolymer electrolyte membrane manufactured from the branched multi-block copolymer defined in claim 1 .
3. A fuel cell comprising the branched multi-block copolymer electrolyte membrane defined in claim 1 .