Investigation of the effect of the amount of additives on the properties of adipic acid esters

Polyvinylchloride (PVC) is the most frequently used polymer for obtaining a wide range of materials for various purposes. The main advantages of the polymer – excellent thermal and electrical insulation properties, high resistance to various aggressive substances, namely: acids, alkalis, various lubricants; lack of taste, smell; low water absorption (0.4–0.6%). The possibility to obtain PVC-plasticates with different characteristics is provided by the introduction of various additives, the bulk of which are plasticizers. Plasticizers based on adipic acid esters give a number of valuable properties to PVC-based compositions. However, the use of plasticizers affects the resistance of compounds to the combustion, therefore, the substances which eliminate this disadvantage are added in the polymer composition. This paper presents the results of a study of the effect of the composition of mixed plasticizers (symmetric and asymmetric adipates of aliphatic alcohols and phosphate of oxypropylated phenol) on the flammability of PVC composition. Primarily symmetric adipate of cyclic aliphatic alcohols and asymmetric adipate of aliphatic alcohols containing cycloalkyl radical have been derived. Then phosphate of oxypropylated phenol has been synthesized. Physical and chemical properties of the synthesized compounds were studied. Mixtures of plasticizers on the basis of the symmetric adipate of cyclic aliphatic alcohols and asymmetric adipate of aliphatic alcohols containing cycloalkyl radical with varying amounts of phosphate of oxypropylated phenol have been composed. The results of tests of PVC compositions containing the obtained mixtures of plasticizers for flammability are presented. Combustibility parameters of cable plasticate samples with the use of developed plasticizers correspond to state standard 5960-72 with changes 3-9. The best results were achieved with the use of asymmetrical adipate of aliphatic alcohols containing cycloalkyl radical and 4% by weight phosphate of oxypropylated phenol. It is shown that small amounts of phosphate oxypropylated phenol are able to reduce flammability, further addition of this plasticizer leads to a deterioration in performance. The developed formulations of PVC plastics are recommended for use in the production of polyvinylchloride cable sheaths.