Effect of poly(4-tert-butylstyrene) block length on the microphase structure of poly(ethylene oxide)-b-poly(4-vinylbenzyl chloride)-b-poly(4-tert-butylstyrene) triblock terpolymers

A series of linear poly(ethylene oxide)-b-poly(4-vinylbenzyl chloride)-b-poly(4-tert-butylstyrene) (PEO(113)b-PVBC (130)-b-PtBS x or E-113 V-130 T-x) triblock terpolymers with various lengths x (=20, 33, 66, 104, 215) of PtBS block were synthesized via a two-step reversible addition-fragmentation chain transfer (RAFT) polymerization. The E-113 V130Tx triblock terpolymers were non-crystalline because the PVBC and PtBS blocks strongly hindered the crystallization of PEO block. The effects of PtBS block length x on the phase structures of E113V130 T x triblock terpolymers were investigated by combined techniques of small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). It was found that with increasing x from 20 to 215, the phase structure of E113V130 T x triblock terpolymers became more ordered and changed from disordered structure, hexagonally-packed cylinder (HEX), hexagonally perforated layer (HPL), to lamellar (LAM) phase structures. Temperature-variable SAXS measurements showed that the HEX, HPL and LAM phase structures obtained for E-113 V130T66, E113V130 T-104 and E-113 V130T215 by thermal annealing, respectively, were thermodynamically stable in the temperature range of 30-170 degrees C. (c) 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.