A series of regiospecific, alkyl-substituted oligothiophenes were synthesized and their structure/property relationships were studied. The formylation of the oligothiophenes introduced an aldehyde functionality into one of the terminals which can be used to couple with living anionic polystyrene species to generate diblock copolymers. Three diblock copolymers were synthesized by coupling the oligothiophene aldehyde with living polystyrenes of different chain lengths. These copolymers were stable at temperature up to 380 degrees C and have similar glass transition temperatures to the corresponding polystyrene homopolymers.