Research On New Plasticizers Based On Extracorporeal Blood Circuits

By means of plasticizers,the processing performance and the mechanical properties of PVC can be improved and the softness and transparency of PVC products can be adjusted as we want.Thus,plasticizers are commonly used in production of PVC-made medical apparatus and instruments.One of the most commonly used plasticizer is di-2-ethyl hexyl phthalate(DEHP).But a growing number of studies have demonstrated that this kind of plasticizer is not safe,and may even cause a certain degree of harm to human bodies.Moreover,as one of commonly used medical instrument in Class-III Medical Devices,extra corporeal blood circuit demands more in functions and performances,making it inevitable to search and find new alternatives for the current plasticizers.However,relevant researches on alternative products are not satisfactory in progress,and DEHP cannot be replaced effectively for the PVC applications especially in the production of extra corporeal blood circuits till now.For this purpose,several possible alternatives were investigated in this paper according to relevant state laws and regulations to obtain a relatively systematic and comprehensive evaluation results focusing on test methods,the plasticizer performances and safety,which may be beneficial to alternating research and industrial application of medical PVC plasticizers.The main research contents are as follows.The heat stability,tensile strength,elongation at break and hardness of DEHP,acetyl tributyl citrate(ATBC)and di-isononyl cyclohexane-1,2-dicarboxylate(DINCH)were tested based on GB15593-1995 standard.The differences of their appearance,fracture strength,heat resistance,pressure proof,and fatigue properties were obtained after the practical tests to confirm the alternating possibilities for perspective of materials.An effective test method of GC/MS for the tests of dissolving-out amounts of DEHP,DINCH and ATBC in disposable extra corporeal circulation lines was established.The differences of the dissolving-out amounts of three plasticizers at three different digestion schemes were studied,and the influences of digestion methods on dissolving-out amounts of DEHP,DINCH and ATBC were explored.The threshold values of DEHP,DINCH,and ATBC for sensitive groups include adults and infants were suggested according to the internationally recognized safety evaluation regulations after the detailed calculations about the allowed limited values of DEHP,DINCH,and ATBC.