iii) chain extending agents and {TAIL ~ crosslinking agents} having {HEAD ~ an average molecular weight} of 62 to 500 and having an average functionality of 2 to 4 and 
iii ) chain extending agents and { TAIL ~ crosslinking agents } having { HEAD ~ an average molecular weight } of 62 to 500 and having an average functionality of 2 to 4 and
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH