TY - JOUR
T1 - Synthesis of polystyrene-B-Poly(ethylene glycol) block copolymers by radical exchange reactions of terminal RAFT agents
AU - Arslan, Mustafa
AU - Yilmaz, Gorkem
AU - Yagci, Yusuf
PY - 2014/4/3
Y1 - 2014/4/3
N2 - In this study, a mechanistic transformation was achieved by taking advantage of coupling reaction of reversible addition-fragmentation chain transfer (RAFT) agents. Polymers prepared by different polymerization modes were coupled to form polystyrene-b-poly(ethylene glycol) (PS-b-PEG) block copolymer. For this purpose, two prepolymers, namely azo and RAFT functional polymers were prepared independently. In the first step, a new macroazoinitiator (MI)-containing PEG units was synthesized by direct esterification of 4,4-azobis(4-cyanopentanoic acid) (ACPA) with poly(ethylene glycol) (PEG) at ambient conditions. The other component, polystyrene (PS) was synthesized by atom transfer radical polymerization and modified with a reversible addition-fragmentation chain transfer (RAFT) agent (xanthate moiety) and used as a polymeric RAFT agent for the block copolymer formation. In the block copolymerization process, polymeric radicals stemming from the thermolysis of PEG-MI were coupled with the RAFT moiety of PS. The PEG-MI, PS, PS-XANTH, and PS-PEG block copolymers were characterized by spectral analysis using FT-IR, 1H NMR, GPC, and DSC.
AB - In this study, a mechanistic transformation was achieved by taking advantage of coupling reaction of reversible addition-fragmentation chain transfer (RAFT) agents. Polymers prepared by different polymerization modes were coupled to form polystyrene-b-poly(ethylene glycol) (PS-b-PEG) block copolymer. For this purpose, two prepolymers, namely azo and RAFT functional polymers were prepared independently. In the first step, a new macroazoinitiator (MI)-containing PEG units was synthesized by direct esterification of 4,4-azobis(4-cyanopentanoic acid) (ACPA) with poly(ethylene glycol) (PEG) at ambient conditions. The other component, polystyrene (PS) was synthesized by atom transfer radical polymerization and modified with a reversible addition-fragmentation chain transfer (RAFT) agent (xanthate moiety) and used as a polymeric RAFT agent for the block copolymer formation. In the block copolymerization process, polymeric radicals stemming from the thermolysis of PEG-MI were coupled with the RAFT moiety of PS. The PEG-MI, PS, PS-XANTH, and PS-PEG block copolymers were characterized by spectral analysis using FT-IR, 1H NMR, GPC, and DSC.
KW - RAFT agent
KW - block copolymer
KW - macroazoinitiator
KW - poly(ethylene glycol)
KW - polystyrene
UR - http://www.scopus.com/inward/record.url?scp=84887454730&partnerID=8YFLogxK
U2 - 10.1080/15685551.2013.840478
DO - 10.1080/15685551.2013.840478
M3 - Article
AN - SCOPUS:84887454730
SN - 1385-772X
VL - 17
SP - 238
EP - 244
JO - Designed Monomers and Polymers
JF - Designed Monomers and Polymers
IS - 3
ER -