{'fraction_non_alphanumeric': 0.026771653543307086, 'fraction_numerical': 0.002362204724409449, 'mean_word_length': 5.2, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Novel aspects in the structure of poly(ethylene terephthalate) as revealed by means of small angle x-ray scattering

The absolute intensity of the small-angle X-ray scattering (SAXS) of poly(ethy1ene terephthalate) (PET) samples crystallized at different temperatures for different times was measured by means of a Kratky camera. The correlation function and the interface distribution function were calculated, and the values obtained from different methods for the long period L, the crystal thickness, l,, the thickness of the amorphous regions la, and the linear degree of crystallinity XCL were compared with each other. After a critical examination of the different methods, including model calculations of the interface distribution function and the correlation function, it is shown that, in the case of a broad distribution of thicknesses, the interface distribution function gives the more reliable results for l , , la , and L. By comparing the linear degree of crystallinity x c ~ determined from SAXS with the degree of crystallinity x c as determined from wide-angle X-ray scattering or from density, it is concluded that the material is not homogeneously filled with lamellar stacks. The coherently scattering lamellar stack consists of only 3-6 lamellae.