Kinetics of shear microphase orientation and reorientation in lamellar diblock and triblock copolymer melts as detected via FT-rheology and 2D-SAXS

摘要

The microphase orientation/reorientation alignment kinetics behaviour of lamellar PS-b-PB diblock and PS-b-PB-b-PS triblock copolymers under LAOS conditions is studied. By online monitoring the degree of the mechanical nonlinearity during the orientation process, as determined via the higher harmonics in FT rheology [i.e: I-3/1(t), phi(3)(t)], and investigation of the orientation distribution by 2D-SAXS, the kinetics of the microphase alignment for different experimental shear conditions was followed. For di- and triblock copolymers, the shear orientation into parallel alignment is possible and the kinetics of orientation is strongly dependent on the strain amplitude.