Applications of DETA to polymers

Crystallinity can be simply and accurately measured by DETA [19] provided that the sample is dipolar and the chains in the crystalline phase do not contribute a relaxation process at the temperature of measurement. The Onsager equation [20] relating dielectric permittivity to the number of orient-able dipoles per cm (N) and the dipole moment (p) is  

Measurement of e allows N, the number of orientable dipoles per cm to be determined. In a fully crystalline sample Nc is zero. For a fully amorphous sample, N must be determined Na) and then N determined for the semicrystalline polymer Nj. The fraction of orientable dipoles is then directly proportional to the volume fraction of amorphous phase (A)  

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