A Multisegmented Polystyrene with pH-Cleavable Linkages

作者：Kang Tae Hyeon; Lee Hyung il^*

来源：BULLETIN OF THE KOREAN CHEMICAL SOCIETY, 2014, 35(9): 2694-2698.

DOI：10.5012/bkcs.2014.35.9.2694

• ATRP
• Multisegmented
• Click reactions
• Degradable
• Polystyrene

A multisegmented polystyrene (PS) with pH-cleavable ester and carbamate linkages was successfully synthesized by a combination of atom transfer radical polymerization (ATRP) and Cu(I)-catalyzed 1,3-dipolar cycloaddition of azide and alkynes (click chemistry). ATRP was employed to synthesize polystyrene from hydroxyl-terminated initiator using CuBr/N,N,N%26apos;N%26quot;,N%26quot;-pentamethyldiethylenetriamine (PMDETA) as the catalyst. The reaction of the resulting PS with sodium azide yielded the azido-terminated polymer. The hydroxyl group in the other end of the polymer was reacted with 4-nitrophenyl chloroformate (NPC), followed by reaction with propargylamine to produce an alkyne end group with a carbamate linkage. The PS with an alkyne group in one end and an azide. group in the other end was then self-coupled in the presence of CuBr/2,2%26apos;-bipyridyl (bpy) in DMF to yield a desired multisegmented PS. Molecular weight and molecular weight distribution of the self-coupled polymer increased with time, as in the typical step-growth-type polymerization processes. Finally, we demonstrated that the ester and carbamate linkages of the multisegmented PS were hydrolyzed in the presence of HCl to yield individual PS chains.

• 出版日期2014-9-20