US 10,303,056 B2  68  67  -continued  Synthesis Example 5  Synthesis Example 6  Synthesis of Polymer 5  Synthesis of Polymer 4  A 2-L flask was charged with 8.4 g of l-t-butyl-1- cyclopentyl methacrylate, 3.6 g of 4-hydroxyphenyl meth- acrylate, 6.2 g of Monomer 1, 1.0 g of a-methylene-y› butyrolactone, 11.0 g of PAG Monomer 2, and 40 g ofTHF.  The reactor was cooled at - 70°  C. in nitrogen atmosphere,  after which vacuum pumping and nitrogen blow were  repeated three times. The reactor was warmed up to room  temperature, whereupon 1.2 g of AIBN as polymerization  initiator was added. The reactor was heated at 60° C.,  whereupon reaction ran for 15 hours. The reaction solution  was poured into 1 L ofIPA whereupon white solids precipi› tated. The precipitate was filtered and dried in vacuum at 60°  C., yielding Polymer 5.  A 2-L flask was charged with 8.2 g of 3-ethyl-3-exo› tetracyclo[ 4.4.0.l  2’5. l 7’10]dodecanyl methacrylate, 3.6 g of  4-hydroxyphenyl methacrylate, 10.9 g of Monomer 1, 11.5  g of PAG Monomer 1, and 40 g of THF. The reactor was  cooled at - 70° C. in nitrogen atmosphere, after which  vacuum pumping and nitrogen blow were repeated three  times. The reactor was warmed up to room temperature,  whereupon 1.2 g of AIBN as polymerization initiator was  added. The reactor was heated at 60°  C., whereupon reaction  ran for 15 hours. The reaction solution was poured into 1 L  of IPA whereupon white solids precipitated. The precipitate  was filtered and dried in vacuum at 60°  C., yielding Polymer  4.  Polymer4  Polymer 5  0  0  F2  0  C  Y’s03- O  CF3  9  CX s+X)~  0  #  Mw~ 8,300  Mw/Mn~l.78  -continued  0  0  ’-f(  r  0  0  F2  0  C  y  "-s03- O  CF3  9  ~s’0  V  Mw~7,600  Mw/Mn~ 1.76  0  0  0  0  r  0  0  ¢  OH 