{'fraction_non_alphanumeric': 0.027700831024930747, 'fraction_numerical': 0.01662049861495845, 'mean_word_length': 4.519083969465649, '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}}
Study of branching in poly(ethylene terephthalate)

The degree of branching of PET synthesis in the presence of trifunctional compounds, trimellitic acid and glycerol, is studied. It is shown that the introduction to the main chain of 1.5% «branching» units gives up to 6 side chains per one polymer molecule. The chemical formula of the branching units does not influence the degree of branching. At the same time, the structure of the branching unit determines the molecular mass of the main chain at which the side chains begin to grow. For polymers containing up to 5-6 side chains, the T g and the melting point are virtually independent of the molecular mass when the latter varies in the interval M n = (20-70)×10 3