The substructure M may be selected from a substituted or unsubstituted methylene chain, a substituted or unsubstituted oxyalkylene chain, and {HEAD ~ a silicon} containing chain or {TAIL ~ combination} thereof 
The substructure M may be selected from a substituted or unsubstituted methylene chain , a substituted or unsubstituted oxyalkylene chain , and { HEAD ~ a silicon } containing chain or { TAIL ~ combination } thereof
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH