Representatives examples of useful homopolymers include the homopolymers such as polyethylene, polypropylene, poly(l-butene), poly(3-methyl-l-butene), poly( 3-methyll -pentene poly( 4-methyll -pentene poly( 4,4-dimethyll-pentene poly( 3-methyll hexene poly( 4-methyll -hexene and poly(4,4-dimethyl-l-hexene). 7 Useful copolymers include ethylene/propylene, ethylene/ l -bu-tene, ethylene/ l -pentene,