New dialkoxyamine-trithiocarbonate for the synthesis of multiblock copolymers through in tandem RAFT/NMP

作者：St Thomas Claude; Maldonado Textle Hortensia; Cabello Romero Judith N; Macossay Javier; Zhang Xujun; Esturau Escofet Nuria; Guerrero Santos Ramiro^*

来源：Polymer Chemistry, 2014, 5(8): 3089-3097.

DOI：10.1039/c3py01270k

A new strategy for synthesizing multiblock copolymers comprising polystyrene, polyacrylates, poly( N-isopropylacrylamide), etc. is described. The methodology involves the use of a dialkoxyamine-trithiocarbonate (I) to prepare highly end-functionalized polymers through reversible addition-fragmentation chain transfer (RAFT) polymerization at T = 60-70 degrees C. Under RAFT conditions, the integrity of the alkoxyamine end-group is preserved and the central trithiocarbonate group remains active for the preparation of triblock copolymers. Either the alpha,omega-dialkoxyamine homopolymer or triblock copolymers were subsequently chain-extended with styrene using nitroxide-mediated radical polymerization (NMP) at T = 120 degrees C. At this temperature, a tandem polymerization reaction occurs since the trithiocarbonate unit is activated simultaneously. This approach afforded highly pure multiblock copolymers with a narrow molar mass distribution ((D) over bar = 1.3-1.7), which was assessed by size-exclusion chromatography. The diffusion ordered spectroscopy (DOSY) analysis of multiblock copolymers suggests that samples fit well to a single-population model with no evidence of uncoupled blocks detectable. The effectiveness of I for the preparation of a number of multiblock copolymers was demonstrated.

• 出版日期2014