756 Carraher’s Polymer Chemistry O CH O H 3 R O R Isotactic O O C H H H 3 O H C 3 O H O H 3 C R O R Atactic O O C H H CH 3 H 3 O 9/14/2010 3:44:54 PM K10478.indb 756 K10478.indb 756 9/14/2010 3:44:54 PM