Crystal structure and polymorphism
Static crystallization at room temperature 22-23 oC at different crystallization times (4, 12, and 60 days) was applied to crystallize blends before X-ray analysis. The crystal structure and polymorphic form of solidified samples were analyzed by X-ray diffraction (Multiflex Powder X-ray spectrometer, Rigaku, Tokyo, Japan). The copper X-ray tube (wavelength of 1.54 Å) was operated at 40 kV and 44 mA. The measurement scan rate was set at 0.3 per minute in the range 2θ=1-30 at 20 oC. The diffracted peak positions were determined using MDI Jade 9 (MDI, Livermore, CA, USA) software.