Jul.  17,  2014  61  US 2014/0199617 Al  [0421]  The polar group that repeating unit (b) may have is  an acid group is also one especially preferred embodiment. As  Rx  ~ $_{~( }$ O  OMe  -continued  :to  j:  &o  Lll  0  Rx  Rx  ~o  ~  m:CN  Qr  0  0  ~  ~  0  0  0  0  OMe  O  0 