Thermoanalytic study of crosslinked polymers containing isocyanuric rings

Abstract

Studies were carried out on crosslinked polymers, prepared by radical copolymerization of oligoester propylene glycol maleinate phthalate with tris(N-2-hydroxy, 3-allyloxypropyl) isocyanurate cured with different initiating agents. The thermostability and the other properties of the crosslinked polymers were studied by differential thermogravimetric analysis. On the differential thermoanalytic curve of the crosslinked polymers cured with an initiating agent consisting of cyclohexanone hydroperoxide and cobalt naphthenate activator, a clearly marked exothermic effect was observed with a maximum at 100°–110°. It was probably due to the formation of additional cross bonds in the preliminarily cured polymers as a result of a more complete polymerization of vinyl groups. It should be pointed out that in the initial oligoester propylene glycol maleinate phthalate cured under identical conditions, such effect was observed at 140°. When a mixture of cyclohexanone hydroperoxide, isopropyl benzene peroxide and cobalt naphthenate activator was used as an initiating agent, the exothermic peak disappeared with all types of polymers. This indicates that more extensive crosslinking of the polymers was achieved by the use of an initiating system consisting of two peroxides and an activator. This conforms to the i.r. spectra. The studied crosslinked polymers containing isocyanuric rings possess a higher thermostability than the product obtained by curing under identical conditions oligoester propylene glycol maleinate phthalate.