Synthesis of Novel Chain-End-Functionalized Polyethylenes via Thiol-ene Click Chemistry

Chain-end-functionalized polyethylenes (Cef-PEs: PE  S  SH (Cef 1 ), PE  S  furfuryl (Cef 2 ), PE  S  NH 2 (Cef 4 ), PE  S  NH 2 •HCl (Cef 5 ), PE  S  COONa (Cef 6 ), PE  S  CHA(Cef 7 ), PE  S  SO 3 Na (Cef 8 ), PE  S  OH (Cef 9 ) and PE  S  COOH (Cef 10 )) are synthesized by thiol-ene addition of vinyl-terminated polyethylene (v-PE) with 1,2-ethanedithiol, furfurylmercaptan, cysteamine, cysteamine hydrochloride, sodium thioglycolate, L-cysteine hydrochloride, sodium 2-mercaptoethanesulfonate, mercaptoethanol, and thioglycolic acid, respectively. PE  S  t  NCO (Cef 3 ) is obtained by subsequent reaction of Cef 9 with anhydrous 4,4′-MDI. Cef-PE 1–8 are reported for the first time. The conversions of all the reactions are up to 95%–100%. All the Cef-PEs are characterized by NMR, GPC, DSC, FT-IR, and TGA. In the experiments, it is found that alkaline mercaptans and solvents are adverse to the thiol-ene click reactions.