Interference effects from liquid‐crystalline block copolymers: Matrix method and analytical approach

Abstract

In order to calculate the interference effects from liquid-crystalline block copolymers, Biswas and Blackwell have presented an elegant matrix method. For the cases where an analogous, analytical approach can be made, we show that the matrix method leads to the same result as the analytical method. In addition to the conventional reciprocal lattice with reciprocal lattice points at h 2 d ( c ) , where ( c ) is the average periodicity, one has to consider three further reci- procal lattices with reciprocal lattice points h ' 2 d c A , h"2n/cB, and h"'2x/(cA + c,). c, and c,are the lengths of the comonomer units. This method will be illustrated by model calculations for p-benzoate/biphenyl-4,4'-diylisophthalate copolyestersa). Further, interesting possibilities of the matrix method will not be treated here. a) Poly[(isophthalic acid-ult-biphenyl-4,4'-diol)-co-4-hydroxybenzoic acid].