ntly, having monomers comprising, a monomer of the formula: ##STR8## where R1 is hydrogen or an alkyl having from 1 to 4 carbon atoms and R2 is an alkyl or a cycloalkyl group having from 1 to 10 carbon atoms, or wherein R2 is R5 -silyl-R6 or R5 -siloxane-R7 where R5 is non-existent, or hydrogen, or an alkyl containing from 1 to 10 carbon atoms and where R6 or R7 is non-existent, hydrogen, or an al