COPOLYMERIZATION OF UNSATURATED OLIGOESTERS MODIFIED WITH NITROGEN-CONTAINING COMPOUNDS WITH METHYL METHACRYLATE

Abstract

In the present work, the kinetics of radical copolymerization in solution at the initial stages of polyglycol maleinate phthalates modified with nitrogen-containing compounds with methyl methacrylate in a ratio of 1:1 was studied. Cyclohexanone was used as a solvent, and benzoyl peroxide was used as an initiator. The study was carried out at temperatures of 50 and 60 °C by dilatometry using collapsible dilatometers and a centrifuge. 13 amine-containing compounds of different types were chosen as modifiers. Also, for comparison, the possibility of using amides and hydrazines as modifiers was checked. Polycondensation was carried out in an oil bath at 175 °C and with vigorous stirring with water withdrawal until a constant acid number was reached. It is shown that the addition of 0.1 mol/l modifier during the polycondensation of a mixture of maleic and phthalic anhydrides with ethylene glycol makes it possible to obtain an unsaturated oligoester, for which the temperature coefficient of the reaction of its copolymerization with methyl methacrylate is significantly reduced. This allows for non-isothermal curing to increase the volume of the copolymer block without the risk of overheating and destruction. Of the studied amines, para-aminoacetophenone turned out to be the most effective; its use as a modifier makes it possible to reduce the temperature coefficient of the reaction from 2.1 to 1.7. The rate of copolymerization at the initial stages for the studied modified systems decreases from 2 to 20 times. The results of the work allow us to propose a technology for the production of polymeric materials by molding them in blocks of much larger sizes than with the use of traditional unsaturated oligomers. Also, calculations were carried out according to a special technique and the maximum size of a copolymer block in the form of a cylinder was determined, in which the height is equal to the radius, which can be obtained by forming it in a non-isothermal mode in a thin layer form with convection air cooling and the maximum allowable temperature in the system is 90 °C. It is shown that the volume of such a block, when using some modified oligomers, increases significantly. Some physical and mechanical characteristics of the obtained copolymers with methyl methacrylate were determined, and it was shown that modification with nitrogen-containing compounds does not improve or worsen the studied characteristics.