The effect of curing modes on the parameters of molecular meshes of epoxy and polyester copolymers

Aliphatic polyesters are an attractive class of biologically based polymers [1]. However, the thermal and mechanical properties, as well as the service life of products based on polysebacates, as with other saturated polyesters, are unsatisfactory for certain applications [2]. The introduction of modifying resins as hardeners promotes the formation of mesh polymers [3]. The scope of application of the copolymers obtained depends on the degree of crosslinking of the components and the parameters of the molecular grids, which can be adjusted during the curing process and which determine their physico-mechanical and operational characteristics [4]. An important confirmation of the formation of a spatial grid in a copolymer is its swelling value in a thermodynamically good solvent [5]. The possibility of directional variation of the crosslinking parameters of epoxy and polyester resins using a polyamide hardener has been determined. For this purpose, the influence of temperature regimes of curing, mixing technology and the ratio of the initial components have been studied. The values of the Huggins constants were initially calculated, and the use of chloroform, xylene, and dimethyformamide was investigated for this purpose. Based on the results obtained, a solvent was selected that provides optimal swelling criteria for the synthesized copolymer. Experimental data describing the swelling process of copolymer samples have been obtained. Using the Florey equation, the parameters of the structural meshes of the developed polymer compositions are calculated.