| Popis: |
Plasticizers are the most popular and indispensable plastic additives, facilitating their processability and providing suitable flexibility. Plasticizing efficiency is a term that is used to compare between different types of plasticizers. Plasticizing efficiency can be assessed using specimen fabricated through either a three-stage method consisting of mixing, extruding and pelletizing, or a solution casting method. In this paper, we aim to compare the results of plasticization efficiency assessed for specimen fabricated through both methods, to reveal their applicability and possible limitations. As an experimental model, we used poly(vinyl chloride) plasticized with three common plasticizers, namely bis(2-ethylhexyl) terephthalate, bis(2-ethylhexyl) phthalate and tris(2-ethylhexyl) trimellitate. Plasticization efficiency assessment was based on mechanical, thermal and migrability properties, including elongation at break, tensile strength, exudation and leaching in n-hexane, thermal stability, and glass transition temperature. The results revealed inconsistencies in the assessment of plasticization efficiency depending on plasticization method. For instance, the migration resistance studies showed that plasticizer release was much faster from solution casted specimens than from the moulded ones. On the other hand, higher tensile strength and elongation at break values were obtained for samples prepared by a solution casting method. The dependency of the results on the method of specimens’ plasticization highlights it as a factor that overestimates/underestimates plasticizer efficiency, and could affect the process of selection of plasticizers for industrial practice. |
