After the polymerization, chloroform was added to the reaction flask to dissolve the final products and remove the catalyst via normal filtration. The obtained chloroform solution was then concentrated and added dropwise into excess of freezer-cold methanol (-20 °C) under continuous stirring. The obtained methanol solution with precipitated white polymer product was then filtered, washed three times with freezer-cold methanol, collected, and vacuum-dried at 40 °C for 24 h.