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