▁for ▁other ▁alpha - ole f ins , ▁Hor ne ▁cop ol ym er ized ▁eth yl ene ▁with ▁other ▁o lef ins ▁as ▁a ▁means ▁of ▁cont rolling ▁the ▁poly eth yl ene ▁density . ▁With ▁the ▁success ▁of ▁the ▁cop ol ym er izations , ▁he ▁decided ▁to ▁try ▁to ▁cop ol ym er ize ▁eth yl ene ▁with ▁is op rene , ▁with ▁the ▁thought ▁of ▁getting ▁a ▁cop ol ym er ▁that ▁could ▁be ▁vul can ized ▁with ▁sul fur ▁in ▁a ▁typical ▁rub ber ▁reci pe . ▁While ▁Professor ▁Z ieg ler ▁did ▁not ▁report ▁the ▁polym er ization ▁of ▁di enes ▁with ▁his ▁catal yst , ▁Hor ne ▁saw ▁no ▁reason ▁why ▁a ▁cop ol ym er ▁or ▁a ▁hom opol ym er ▁could ▁not ▁be ▁made ▁from ▁a ▁pure ▁hydro car bon ▁di ene . ▁Actually , ▁Karl ▁Z ieg ler ▁had ▁said ▁that ▁they ▁were ▁un success ful ▁in ▁polym er izing ▁di enes . ▁With ▁Hor ne ' s ▁in quis itive ▁nature ▁and ▁determ ination , ▁he ▁tried ▁the ▁cop ol ym er ization ▁of ▁eth yl ene ▁and ▁is op rene . ▁Hor ne ▁submitted ▁the ▁eth yl ene / is op rene ▁cop ol ym er ▁for ▁inf ra red ▁exam ination . ▁When ▁Jim ▁Sh ip man , ▁who ▁was ▁responsible ▁for ▁the ▁analysis , ▁exam ined ▁the ▁inf ra red ▁spectrum , ▁he ▁immediately ▁called ▁Hor ne ▁and ▁said , ▁" Are ▁you ▁trying ▁to ▁fool ▁us ? ▁We