Terpolymers of ethylene, vinyl acetate, and styrene as pour point depressants for distillate fuels

摘要

The flow properties of petroleum distillate fuel oils at low temperature are improved by adding a pour point depressant amount of certain terpolymers of ethylene, vinyl acetate and styrene, particularly characterized as having more uniform macromolecular composition and distribution of monomer constituent units polymerized in the terpolymer macromolecules, made by terpolymerization under steady state conditions and pressure at least 1000 atmospheres and temperature at least 200. degree. C.