TECHNOLOGY FOCUS - POLYMERS - Preferred Method: The ion exchange resin made of perfluoropolymer is obtained by hydrolyzing a polymer and converting the polymer to an acid form. The polymer comprises a segment made of an amorphous polymer having fluorosulfonyl groups, and another segment made of amorphous polymer without IEG. The ion exchange resin is also obtained by (i) homopolymerization of perfluoro(vinyl ether) monomer having -SO2X group or copolymerization of perfluoro(vinyl ether) monomer with another perfluoromonomer, by iodine transfer polymerization, in the presence of an iodine containing fluoro-compound. Subsequently, (ii) homopolymerization or copolymerization of perfluoromonomer without IEG is carried out by iodine transfer polymerization, in presence of the obtained polymer. Alternately, polymerization (i) is performed after polymerization (ii).X = fluorine, chlorine or OM (preferably, chlorine or fluorine); andM = hydrogen, alkali metal or NH4.The iodine containing fluoro-compound is perfluoroalkyl monoiodide.Preferred Segment: The ion exchange resin is made of polymer, in which the segments (C) and (D) contains segments (A) and (B), respectively. The segment (C) is made of a copolymer comprising repeating units of perfluorovinyl ether having a sulfonic acid group and repeating units of TFE. The resin is made of polymer, in which the segments (C) and (E) contains segments (A) and (B), respectively. The segment (E) is made of copolymer without IEG and comprising repeating units of perfluorovinyl ether and repeating units of TFE. The polymer comprises segments (C') and (E). The segment (B) has alicyclic structures in its main chain. The segment D is made of poly(perfluoro(3-butenyl vinyl ether)), poly(perfluoro(alkyl vinyl ether)), poly(perfluoro(3,5-dioxa-1,6-heptadiene)), poly(perfluoro(2,2-dimethyl-1,3-dioxole)), poly(perfluoro(1,3-dioxole)), poly(perfluoro(4-methoxy-1,3-dioxole)), TFE/perfluoro(2,2-dimethyl-1,3-dioxole) copolymer or poly(perfluoro(2-methyl-4-methyl-1,3-dioxolane)). The mass ratio of each of segment (A) and segment (B), segment (C') and segment (D), and segment (C') and segment (E), is 95/5-5/95. The perfluoroalkylvinyl ether is perfluoro(alkyl vinyl ether) represented by formula CF2=CF-(OCF2CFZ)t-O-Rf.Z = fluorine or trifluoromethyl group;Rf = 1-12C perfluoroalkyl group; andt = 0-3.Preferred Monomer: The monomer group (b) comprises fluoromonomer. One of the monomer groups (C) and (D) contains monomer groups (a) and (b), respectively. The monomer (c) is perfluorovinyl ether having SO2X' group, where X' is fluorine or chlorine, and TFE. The monomer (d) is perfluoromonomer without IEG and having an alicyclic structure, or perfluoromonomer without IEG and having alicyclic structure and at least one other perfluoromonomer without IEG. One of the monomer groups (c) and (d') contains monomer groups (a) and (b), respectively. The monomer (d') is perfluoromonomer without IEG and having two double bonds capable of cyclopolymerization, or perfluoromonomer without IEG and having double bonds capable of copolymerization and at least one other perfluoromonomer without IEG. One of the monomer groups (c) and (e) contains monomer groups (a) and (b), respectively. The monomer (e) is perfluoro(alkyl vinyl ether) without IEG and TFE.Preferred Properties: The block polymer is perfluoropolymer having glass transition temperature of 270 degrees C or less. The segments without crystalline melting point (Tm), or with (Tm) of 270 degrees C or less, is present in the polymer. The polymer obtained after polymerization of monomers (I,II) is substantially amorphous. EXAMPLE - 1-iodoperfluorobuatane (in gram) (4.5) and perfluoro(propylene vinyl ether) (PPVE) (706.5) were added to an autoclave and heated. Tetrafluoroethylene (TFE) (88) and 5 ml of solution containing IPP of formula (I) (5.36) and HCFC225cb of formula (II) (78.2) were added and polymerized under 0.66 MPa. IPP (1.6) and TFE (80) were further and the obtained solution was poured into HCFC141b of formula (III) for flocculation followed by filtration, and dried to obtain TFE/PPVE copolymer segments. Copolymer of TFE having ion exchange capacity of 1.46 meq/g dry resin and molecular weight (Mw) of 27400, and PPVE having Mw of 12200 (80) and PSVE of formula (IV) (778.5), were added to autoclave, heated and stirred. TFE (60), 6 ml solution of IPP (2.8) and HCFC225cb (78.6) were injected, maintained under 0.49 MPa and polymerized. IPP (1.17) and TFE (55) were further added to the reaction mixture. The obtained solution was poured into HCFC141b followed by filtration and dried to obtain (TFE/PPVE copolymer)-(TFE/PSVE copolymer) block copolymer (268.5) with ion exchange capacity of 1.01 meq/g dry resin and Mw of 39600. The polymer was converted to acid form and solution. The solution was cast to form film which had water-content of 145%. The fuel cell formed using the TFE/PSVE copolymer and the solution had terminal voltage (measured after 1000 hours) of 0.62V. The operation of the fuel cell was continued for 1000 hours.