{HEAD ~ Compounds} of formula B1 with amide group X are diamides obtained from macromolecular diamines by well known acylation reactions using e.g., {TAIL ~ the acid chlorides} or anhydrides mentioned above 
{ HEAD ~ Compounds } of formula B1 with amide group X are diamides obtained from macromolecular diamines by well known acylation reactions using e.g. , { TAIL ~ the acid chlorides } or anhydrides mentioned above
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH