{'fraction_non_alphanumeric': 0.03114571746384872, 'fraction_numerical': 0.025583982202447165, 'mean_word_length': 5.569343065693431, '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}}
Synthesis and Properties of Novel Nonlinear Optical Polyimide Containing Nitrophenylazoresorcinoxy Group

New Y-type polyimide (4) containing nitrophenylazoresorcinoxy groups as NLO chromophores, which are components of the polymer backbone, was prepared and characterized. Polyimide 4 is soluble in common organic solvents such as N,N-dimethylformamide and dimethylsulfoxide. It shows a thermal stability up to 290°C in thermogravimetric analysis with glass-transition temperature (Tg) obtained from differential scanning calorimetry near 128°C. The second harmonic generation (SHG) coefficient (d 33) of poled polymer film at the 1064 nm fundamental wavelength is around 5.46 × 10−9 esu. The dipole alignment exhibits a thermal stability up to T g, and there is no SHG decay below 130°C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.