Huanhuan Liu, Xiao Jiang, Rongjian Bian,
Min Tong, Dandan Tang, Xiangdong Zhou, Youliang Zhao*, “Facile synthesis of A2mB2n-type
starlike copolymers with two types of V-shaped arms by combination of RAFT,
ATRP and ROP processes”, Polymer, 2015, 64, 249–259
(DOI: 10.1016/j.polymer.2015.01.059).
http://www.sciencedirect.com/science/article/pii/S0032386115001184
Controlled
synthesis of A2mB2n-type (m ≈ n ≈ 8)
starlike copolymers comprising an oligomeric poly(styrene-co-maleimide) core and two types of V-shaped
arms individually generated by ATRP and ROP was described. Multistep syntheses
involving RAFT copolymerization, end group removal, ATRP of vinyl monomers such
as styrene (St), methoxyethyl methacrylate (MEMA) and tert-butyl
acrylate (tBA),
and ROP of ε-caprolactone (CL) were used to construct the
target miktoarm stars with controlled molecular weight and relatively low
polydispersity (PDI = 1.07–1.22). The resultant star copolymers had
high bromide functionality and uniform chain length of ATRP-generated arms,
evident from chain extension polymerization and cleavage of arms. Meanwhile, a
pH-responsive (PAA)2m(PCL)2n star was also obtained by selective
hydrolysis. The synthetic strategy via combination of RAFT copolymerization and
“core first” approach is versatile in constructing various A2mB2n stars, and this study further
paves way for facile synthesis and properties of new types of miktoarm stars.