The review presents an analysis of modern studies of the synthesis and use of fire retardants of various nature. The cited literature data show that the restrictive requirements of international and Russian legislative acts restrain the use of halogen-containing flame retardants, which determined the direction of research development towards organic compounds of phosphorus and nitrogen. The use of halogen-containing fire retardants has become possible when they are used together with inorganic fillers capable of binding toxic low-molecular products formed during combustion and pyrolysis.
Objectives. To synthesize phosphorus-containing oligoestermethacrylates spatially separated by spacers of aliphatic or aromatic structure and evaluate their effect on photocuring kinetics.Methods. For determining the qualitative and quantitative composition of the synthesized compounds, the following methods were used: thin layer chromatography; chromatographic and mass spectrometry; infrared spectroscopy; 1H, 13C, 31P nuclear magnetic resonance spectroscopy; differential scanning calorimetry. The dielectric loss tangent was determined on a specially designed optical cell with an ultraviolet (UV) light source to an immittance meter. Elemental analysis was performed on an energy dispersive X-ray fluorescence spectrometer.Results. Spatially separated oligoestermethacrylates based on phosphorus trichloride containing aliphatic or aromatic spacers in the structure were synthesized. During the interaction of glycidyl methacrylate with phosphorus trichloride in the mass of the latter, reaction products were shown to be formed both according to the Krasusky rule from the side of the α-carbon atom, as well as against this rule with the formation of isomeric products. Obtaining these compounds in bulk is possible only in the presence of a homopolymerization inhibitor. The influence of the spacer structure on the curing rate of oligoestermethacrylates under the action of UV radiation has been established. It has been shown that the introduction of a spacer into the oligomer structure is accompanied by an increase in the induction period by a factor of 39 compared to a sample without a spacer.Conclusions. The results obtained indicate the possibility of obtaining new oligoestermethacrylates with aliphatic and aromatic spacers in the structure. The influence of the structure of the spacer on the kinetics of photocuring is determined.
The article presents the results of studies of the features of photorecovery of trifunctional and tetrafunctional phosphorus-containing methacrylates with various spacers in the structure. It was found by differential scanning calorimetry that the introduction of spacers leads to a decrease in the overall thermal effect of the UV-curing process in comparison with a spacerless sample. With the help of a photocell for an E7-25 immittance meter, which is capable of recording changes in dielectric properties over time, the influence of the spacer and its structure on the degree of completion of the UV-curing process was determined. The effect of the introduced spacer on the formation of a crosslinked polymer is shown, which is manifested by different times of the induction period.
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