Investigating the Influence of Different Types of Thermoplastic Elastomer on the Properties of Highly Filled Composites

Abstract

Thermoplastic elastomers (TPEs) are polymeric materials that combine the physicomechanical properties of vulcanised rubbers during service with processability by technology similar to that used for thermoplastic polymeric materials. The application of materials of this kind makes it possible to retain high elastic properties of the material obtained and to process it like a thermoplastic polymer. TPEs are among the new materials being most actively developed. Research in the field of creating materials with unique properties is constantly being carried out, and formulations are being developed for specific articles that meet the requirements both of those who process the plastics and those who end up using them [1]. TPEs are compatible with many polymeric materials, in particular polypropylene. Blends of polypropylene with TPEs are characterised by improved deformation properties by comparison with the initial polymers, including an increased impact strength at low temperatures. Therefore, in industry, the use of such blends has been widespread, in particular for the production of special-shape extruded items sold by length, for example seals for windows, cable sheathing, etc. [2]. An important property of special-shape extruded items sold by length is low flammability of the TPEbased composites. Among the inorganic combustion inhibitors for polyolefins, wide use has been made of aluminium hydroxide Al(OH)3 and magnesium hydroxide Mg(OH)2, which have active functional groups. The main advantages of these combustion inhibitors is their low cost and the significantly lower level of smoking during the combustion of materials containing them by comparison with materials containing organic fireproofing agents. A shortcoming is their low effectiveness by comparison with halogenand phosphorus-containing compounds, as a result of which, for the production of material that extinguishes in air, it is necessary to introduce somewhere in the order of 60% aluminium hydroxide or 57–60% magnesium hydroxide into the polyolefins, depending on the particle size and the specific surface of the fireproofing agent [3]. The application of these fireproofing agents requires control of the level of physicomechanical properties of the composites. The thermoplastic elastomers most widely used in industry for the production of special-shape items sold by length are styrene thermoplastic elastomers TPE-S (block copolymers of styrene with butadiene or isoprene, ethylene butylene, ethylene propylene, etc.), and also blends based on them, including modified blends [4]. However, a considerable shortcoming of composites containing thermoplastic elastomers based on styrene block copolymers is their flammability. The application Plasticheskie Massy, No. 7-8, 2016, pp. 6–8