Synthesis and Solution Self-assembly of pH-responsive ABC Triblock Copolymers

	Synthesis and Solution Self-assembly of pH-responsive ABC Triblock Copolymers
	Sheng, Li; Chen, Hong; Fu, Wen-xin; Li, Zhi-bo
刊名	ACTA POLYMERICA SINICA
	2015-08-20
期号	8 页码:982-988
关键词	ABC triblock copolymer Polypepide Polystyrene Poly (N-isopropylacrylamide) ATRP Hybrid copolymer Micelle
英文摘要	Two polylysine-containing ABC-type triblock hybrid copolymers,poly(ethylene glycol)-b-poly-(TFA-L-lysine)-b-poly(styrene) (PEG-b-PTLL-b-PS) and poly(ethylene glycol)-b-poly(TFA-L-lysine)-b-poly(N-isopropylacrylamide) (PEG-b-PTLL-b-PNIPAM),were successfully synthesized via sequential ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). The diblock precursor,PEG-b-PTLL-NH2 was prepared via the ROP of e-trifluoroacetyl-L-lysine N-carboxyanhydride (Lys(TFA)-NCA) with amino-terminated PEG as the initiator. Then the diblock was converted to a macromolecular initiator (PEG-b-PTLL-Br) through the amidation with 2-bromoisobutyryl bromide in the presence of triethylamine (TEA) and 4-dimethylaminopyridine (DMAP). Two series of triblock hybrid copolymers, PEG-b-PTLL-b-PS and PEG-b-PTLL-b-PNIPAM,were obtained via ATRP under appropriate conditions. The GPC and NMR characterizations verified the successful preparation of triblock copolymers. The above results showed that the DP of each block can be adjusted by molecular design and variation of reaction time. Considering the rich amido groups in both backbone and side chain of PTLL block,we applied a relatively high amount of Cu(I) salts and ligand for effective activation and performed the ATRP in high-polarity organic solvent to overcome the effects of amide groups. Moreover,the self-assembly of amphiphilic PEG-b-PLL-b-PS was explored in mixture solvents at different pH values. It was found that the morphologies of resultant micelles depended on pH values in the water/DMF mixed solvent. When pHK(a) (ca. 10.5),the PEG(45)-b-PLL106-b-PS20 triblock formed spherical micelles. When pH>pK(a),the PEG(45)-b-PLL106-b-PS20 triblock formed disk-like micelles.
收录类别	SCI
语种	英语
公开日期	2015-11-03
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/28376]
专题	化学研究所_高分子物理与化学实验室
作者单位	Chinese Acad Sci, Inst Chem, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Sheng, Li,Chen, Hong,Fu, Wen-xin,et al. Synthesis and Solution Self-assembly of pH-responsive ABC Triblock Copolymers[J]. ACTA POLYMERICA SINICA,2015(8):982-988.
APA	Sheng, Li,Chen, Hong,Fu, Wen-xin,&Li, Zhi-bo.(2015).Synthesis and Solution Self-assembly of pH-responsive ABC Triblock Copolymers.ACTA POLYMERICA SINICA(8),982-988.
MLA	Sheng, Li,et al."Synthesis and Solution Self-assembly of pH-responsive ABC Triblock Copolymers".ACTA POLYMERICA SINICA .8(2015):982-988.