Besides differing in terms of intra-sentential coverage, PropBank and the PDTB also differ in their semantics.
even those PropBank ArgM roles that are closest to discourse relations-ArgM-CAU (causal), ArgM-TMP (temporal), ArgM-PNC (purpose), ArgM-MNR (manner), and ArgM-ADV (adverbial)-differ from the semantics of PDTB senses in several ways.