Partially unsaturated polymers are dissolved in a two component solvent comprising a first component having a reactivity toward ozone less than carbon-carbon double bonds but more reactive than carbon-carbon single bonds and a second component being inert toward ozone. Introduction of ozone into the solution produces ozonides which are readily cleft into difunctional aliphatic species that can be converted to e.g. carboxy-terminated or multifunctional carboxy substituted aliphatic compounds. These may be used as monomeric species in various polymerization schemes as such, in preparation of polyamides, for example, or may be reduced to aldehydes or alcohols to be used in the preparation of such polymers as polyesters, polyurethanes, poly (Schiff bases), etc. The carboxylated products may also be employed as ionomers, which are useful as surfactants. Monocarboxyl terminated polyethylene having a number average molecular weight of from about 4,000 to 100,000 are provided. Poly(carboxymethyl) substituted polyethylenes, wherein from about 0.05 to 1.3 percent of the hydrogen atom or polyethylene are substituted with carboxymethyl groups, are obtained.