The block copolymers may be prepared by selectively hydrogenating substantially all the I polymer units of {TAIL ~ a precursor block copolymer} with a sufficient number of D units in the D polymer blocks retaining their unsaturation on selective hydrogenation to enable {HEAD ~ the vulcanization} of the block copolymer 
The block copolymers may be prepared by selectively hydrogenating substantially all the I polymer units of { TAIL ~ a precursor block copolymer } with a sufficient number of D units in the D polymer blocks retaining their unsaturation on selective hydrogenation to enable { HEAD ~ the vulcanization } of the block copolymer
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL 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 HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH