Synthesis and reactions of cysteine-based telechelic polymers

✍ Scribed by Hiroto Kudo; Fumio Sanda; Takeshi Endo

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 234 KB
• Volume: 39
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/1099-0518(20010101)39:1<23::aid-pola30>3.0.co;2-4

✦ Synopsis

The radical polyaddition of N-4-vinylbenzoyl-L-cysteine methyl ester (VCM) was carried out in the presence of 2,2Ј-azobisisobutyronitrile (AIBN, 3 mol %) as an initiator in dimethyl formamide (DMF) with monomer concentrations of 0.5 and 1.0 M at 60 °C for 20 h under nitrogen atmosphere to afford the corresponding polymers [poly(VCM), PVCM] with number-average molecular weights (M n )'s of 5300 and 18,000 in 92 and 95% yields, respectively. The obtained polymers had a heterotelechelic structure with thiol and olefin end moieties. The radical polymerization of methyl methacrylate and trityl methacrylate was carried out in the presence of PVCM with AIBN (3 mol %) as an initiator in DMF at 60 °C for 20 h to afford the block copolymers with M n values in the range of 13,000 -26,800 in good yields. PVCM [M n ϭ 18,000; polydispersity (M w /M n ) ϭ 1.56] was treated with 4 equiv of NaOH aq. (1.0 M) to afford the polymer having carboxyl groups in the side chain with a M n of 17,300 and M w /M n of 1.88 in 95% yield and was also oxidized to polysulfoxide and polysulfone with 4 equiv of H 2 O 2 per sulfide unit in CH 2 Cl 2 (1.0 M) for 20 h.