Or search: flux, stuff, chemic, carrier, compound, fraction, softener, congener, fumigant, reactant, explosive, pesticide, daminozide, fertilizer, stabilizer
3 Syllables: SUU
chemicals, clerical, ethical, festival, medical, metrical, plentiful, spherical, vesicles
4 Syllables: USUU
heretical, hysterical, identical, indelible, intestinal, nonsensical, numerical, poetical, symmetrical
5 Syllables: UUSUU
academical, alphabetical, antithetical, arithmetical, asymmetrical, biochemical, ecumenical, evangelical, geometrical, hypothetical, theoretical
6 Syllables: UUUSUU
incomprehensible, infinitesimal

Found 31 words across 4 groupings. Skipped 1 excess word of a similar stem.