Blends of two or more polymers may be desirable in some cases and the polymers selected will depend at least to a certain extent on {TAIL ~ the purpose} to which {HEAD ~ the material} is to be put 
to put
Blends of two or more polymers may be desirable in some cases and the polymers selected will depend at least to a certain extent on { TAIL ~ the purpose } to which { HEAD ~ the material } is to be put
OTH OTH OTH OTH 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 REL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL