Dynamic mechanical behavior of a side‐chain liquid crystalline polyacrylate

The phenomenology of the α- and β-relaxation processes in an amorphous and a crystallized specimen of the side-chain LC polyacrylate [CH 2 CH(COOR)] n (R= (CH 2 ) 6 OPh(Me)N=NPhOC 5 H 11 ) was investigated by thermal and dynamic mechanical methods. The activation energy of the β relaxation of the crystallized sample is equal to that of the amorphous sample. The α-transition process of the amorphous sample was described by the WLF equation. In contrast, the α-relaxation behavior of the amorphous part of the semicrystalline sample was described by a double Arrhenius law broken at T = T g . This peculiar behavior has been tentatively related to the decrease of the motion characteristic length of the macromolecules confined in the multidomain structure of the semicrystalline state.