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