DOMINANT FACTORS ON THE MICELLIZATION OF BNEMBN-TYPE TRIBLOCK COPOLYMERS IN AQUEOUS-SOLUTION

The micellization parameters of a series of oxyethylene/oxybutylene (B nEmBn) triblock copolymers (B4E40B4, B5E39B5, B5E91B5, B6E46B6, B7E22B 7, B7E40B7, B10E271B10, and B12E260B12) were summarized to obtain coll ective conclusions on the dominant factors that affect the micellizati on of such sort of triblock copolymers in aqueous solution. The effect s of the block lengths of both the hydrophobic end B blocks and the hy drophilic middle E block on the critical micellar concentrations, the association numbers, the second virial coefficients of micelles, the e nthalpy of micellization, the hydrodynamic radius, and the intermicell ar cross-linking are discussed. It was found that the micellization wa s mainly determined by the B block length while the micellar size and the intermicellar structure were influenced greatly by the E block len gth. The scaling theory that was derived from diblock copolymer micell e models can also be used in triblock copolymer miceller systems.