vinylidene content of the total mono unsaturation present is typically at least about 15 more typically 20 and most typically at least 25 the weight ratio of vinylidene to trisubstituted olefin is about 1 4 to about 8 1 typically about 1 3 to about 5 1 and often at least 1 4 and more typically at least 1 3 the amount of vinylidene and other substituted olefins are conveniently obtained by carbon 13nmr as referred to in determination of molecular structure of hydrocarbon olefins by high resolution nuclear magnetic resonance stehling et al anal chem 38 11 pp 1467 1478 1966 see also 13 c chemical shifts of some model olefins by couperus et al org magn reson 8 pp 426 431 1976 the foregoing articles are incorporated by reference in conjunction with the vinylidene content it is preferred hat the unsaturation content of the polymer is as defined as above and determined by astm d 1159 66 reapproved 1970 herein incorporated by reference the lower alkene polymer is obtained from a lower alkene monomer typically containing from about 2 to about 6 carbon atoms typically the lower alkene monomer contains f amp om about 2 to 4 carbon atoms such as butene and most preferably propylene propene the feed stream of the lower alkene monomer is preferably free of diene or higher moieties the diene or higher unsaturated moieties can lead to the formation of diphenyl alkanes upon alkylation by being substantially free of moieties it is desired that there be no more than.