Effects Of Plasticiser Mixtures On Physical And Mechanical Properties Of Medical Grade Polyvinyl Chloride (Pvc)

Polyvinyl chloride (PVC) has been widely used in manufacturing of disposal, presterilized medical device such as urine bag and urinary tubing due to its flexibility, durability, transparency, sterilization performance, and low cost. Plasticiser typically di-2-etylhexyl phthalate (DEHP) is normally incorporated into PVC resins to increase the flexibility. However, the migration tendency and toxicity of DEHP has led to gradual shift of plasticiser to high molecular weight phthalate or other alternative plasticisers. The effect of different plasticiser mixtures (mixture of dioctyl adipate (DOA) with epoxidised soybean oil (ESO), mixture of diisononyl phthalate (DINP), DOA and ESO and mixture of dioctyl terephthalate (DOTP) with ESO) and different plasticiser concentration on physical as well as mechanical properties of PVC compounds were investigated. PVC resins and additives were compounded by two roll mill machine and compression moulded with hot press machine. The physical and mechanical properties of PVC compounds were examined by conducting tensile test, hardness test, specific gravity test and scanning electron microscopy (SEM). As the plasticisers’ concentration increased, the tensile strength, Durometer hardness and specific gravity of PVC compound decreased while elongation at break increased. Besides that, among three plasticiser mixtures investigated in this study, the combination of DOA and ESO showed highest plasticising efficiency in tensile strength and Durometer hardness but lowest compatibility with PVC resins. The increment on elongation at break was also high but only limited to low plasticiser concentration. On the other hand, PVC compound plasticised with DINP, DOA and ESO posed intermediate tensile strength, Durometer hardness and compatibility. The elongation at break for this combination