We have used small-angle neutron scattering (SANS) technique to study the micellization of a series of alternating comb-shaped copolymers, poly[l-alkene-co-(maleic anhydride)], in the fully neutralized state in water with the 1-alkenes ranging from 1-octene to 1-octadecene and weight-average molecular weights from 6000 to 20000. The structural parameters of the amphiphilic aggregates are determined by analyzing the intraparticle structure factor of the SANS intensity data. The analysis has shown that the copolymer derived from 1-octadecene forms cylindrical-shaped micelles while the copolymers derived from lower 1-alkenes form ellipsoidal-shaped micelles with the transition occurring at the 1-hexadecene copolymer. Analysis of the absolute neutron scattering intensity at zero scattering angle has shown a strong dependence of the mass of the aggregates on the side-chain length, namely, there are approximately 200 monomer repeating units per aggregate for the 1-octadecene copolymer versus about 20 monomer repeating units per aggregate for the 1-octene copolymer. The effect of molecular weight on aggregation is not observed possibly due to the polydispersity in the copolymers.

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