{'fraction_non_alphanumeric': 0.03581460674157303, 'fraction_numerical': 0.013342696629213483, 'mean_word_length': 5.038135593220339, '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 Characterization of a Flame Retardant Dimethyl Methyl Phosphonate (DMMP) and its Application in FRP

Dimethyl Methyl Phosphonate (DMMP) was synthesized via the MichaelisArbuzov rearrangement in the normal pressure and N2 atmosphere using a novel and can be used repeatedly catalyst. The preparation conditions of DMMP, such as the reaction time, reaction temperature and catalyst dosage were investigated. The FTIR (Fourier transform infrared spectroscopy), NMR (Nuclear magnetic resonance) , and TG-DSC(Thermogravimetric-Dynamic stability control system) results show that the obtained product is DMMP. When the reaction temperature is higher than 180°C, catalyst dosage is 12 wt%, and the reaction time is about 13 h, the highest yield (78 wt%) of DMMP can be obtained. Then DMMP was added to a FRP (Fiber Reinforced Plastics) matrix. The flame retardancy and mechanical properties of the DMMP/ FRP were tested for Limiting Oxygen Index (LOI), breaking elongation, impact toughness, tensile, and flexural strengths. A significant improvement of flame retardancy of the system was observed (increase of LOI up to 30.4) with an addition of 10 wt% DMMP to FRP. But when the DMMP content in the DMMP/ FRP composites is more than 10 wt%, the comprehensive mechanical properties of FRP will appear to decline and the LOI value has not changed, so we conclude that DMMP content in the DMMP/ FRP composites is 10wt%.