STAR-SHAPED ALKYL CARBAMATES AS POUR POINT DEPRESSANTS

A series of trialkyl carbamates of the general formula HC(PhNHCOOCnH2n +1)(3) with n = 16, 18, 20 and 22 were synthesized from alkanols and t ris(p-isocyanatophenyl)methane. The star-shaped compounds effectively depress the pour point of wax-containing paraffin oil. A quantity of 0 .1 wt. % of the C18 derivative, by far the most effective depressant, reduced the pour point of paraffin oil containing 11.5 wt. % wax (mp 5 6-61 degrees C) from 33 degrees C to -4 degrees C. The extent of the d epression varies with the concentration and composition of the wax. Th e depressants are ineffective when pure alkane waxes are added to the paraffin oil.