Study of biodegradability of the vegetable oil modified epoxy coatings

АBSTRACT Introduction. For solving environment protection problems and reducing the volume of ‘polymer waste’, the study of biodegradability of polymer materials by means of their modification without impairing main performance is of practical importance. This is achievable by application of biodegradable natural additives. The radical solution is the development of polymer materials that are capable of retaining their performance throughout their service life only. Materials and methods. To modify compositions, APh-2 aminoalkylphenol-cured ED-20 epoxy diane resin was used. Liquid fraction of rubber tree oil (RTO) and Vietnam-produced soybean oil (SO) were used as the modifiers. Biodegradability of the materials was evaluated by Sturm’s method checking respirometric activity of soil in their presence. Resistance of the epoxy materials to microbiological putrefaction in soil was investigated by mass loss value. Thermal stability of the epoxy coatings was tested by simultaneous thermal analysis on Netzch-Gerätebau GmbH apparatus at the heating rate 10 °C/min when the temperature varying within the range of 25 °C to 600 °C. Water absorption was evaluated as per GOST 4650-2014 standard. Sol-gel analysis was implemented in boiling acetone in the Soxhlet apparatus. Abrasion hardness of epoxy materials was carried out on the IZV-1 vertical optical caliper. Hardness was checked by Barcol impressor. Frictional factor was determined by means of the CSM Instruments Tribometer automated friction machine. Results. Applying vegetable oils governs a significant growth of the abrasion resistance and enhancement of antifriction characteristics of epoxy materials. The vegetable oils exercise a plasticizing effect on epoxy compositions, accelerate processes of epoxy material biodegradation in soil and reduce their resistance to micromyces. Epoxy resin is characterized with high funginertness and its modification by the RTO results in enhancement of biodegradability when exposed to mouldy fungi. Conclusions. Applying the RTO as a modifier of the epoxy materials accelerates processes of their biodegradation in soil and decreases their resistance to micromyces. The higher biodegradation of vegetable oil-modified epoxy films takes place at complex exposure to bacteria and mycelian fungi as a part of soil microbiocenosis.