We have reported the influence of primary structure of the main chain on backbone stiffness of the cylindrical rod brushes. Interestingly, the rod brushes consisting of polymethacrylate main and poly(n-hexyl isocyanate) (PHIC) rodlike side chains were much stiffer than that of polystyrene main and same PHIC side chains. Figure shows the double logarithmic plots of z-averaged mean-square radius of gyration (<S2>z1/2) versus the weight averaged degree of polymerization of the main chain for poly(MA-EO1-HIC-63-Ac) and poly(VB-HIC-62-H) in THF at 25 �C. The present study is aimed to clarify why chain stiffness of polymethacrylate main chain is much higher than that of polystyrene, in spite of having the same side chains. Conformational properties of cylindrical rod brushes having a flexible spacer between main and side rod have thoroughly been studied by static light and small-angle X-ray scatterings in THF at 25 �C. These rod brushes were prepared by radical homopolymerization of PHIC macromonomer (MA-EOm-HIC-Ns-Ac, where Ns is the weight-averaged degree of HIC). EO is an oxyethylene between the main and PHIC side chains (m = 1, 2, 4.5, 8). The molecular weight dependence of <S2>z1/2 of the brush is determined and analyzed in terms of the wormlike cylinder model. The backbone stiffness of poly(MA-EO2-HIC-Ns-Ac) is larger than that of the poly(MA-EO1-HIC-Ns-Ac) with the corresponding contour length, implying the effects of the flexible spacer on the conformation of the rod brushes.Figure.  NM dependence of <S2>z1/2 for P(MA-EO1-HIC-63-Ac), P(VB-HIC-62-H), and PMMA in THF at 25 �C.

Influence of primary structure of the main chain on the solution properties of the rod brushes

248th National Meeting (2014)

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