Aug.  27,  2020  116  US 2020/0272048 Al  -continued  [0092]  In another preferred embodiment, the base polymer  may further comprise recurring units ( d) derived from  indene,  benzofuran,  benzothiophene,  acenaphthylene,  chromone, coumarin, and norbornadiene, or derivatives  thereof. Suitable monomers are exemplified below.  6  ~  #OJA~ #O)y’  I~  I  I  :( •’(Yo  0  )-i  _FJ  :(’  :(  o ,~o  -continued 