Integrated Intensity as a Function of Annealing Time

The X-ray diffraction patterns of as-drawn PET samples have a weak 001 reflection on the meridian. This implies that the initial state of oriented PET is a mixture of the nematic structure and the smectic structure, and also that two ordering processes coexist during the isothermal annealing process on PET. (Polymer chains in the nematic structure have a preferred orientation 

It should be noted here that the intensity of the 00 T reflection does not seem to decay to zero, but to a finite value, depending on annealing temperature. 

---