Abstract:
The objective of this thesis was to study the appropriate polymer for preparation of thermoplastic masks for medical applications. The commercial thermoplastic mask was characterized by Fourier
transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The results indicated that the type of polymer was polycaprolactone. The tensile strength, hardness and impact
strength of the commercial thermoplastic mask were 17.35 MPa, 51.40 D Scale and 9X 10-3 J/(mm)2, respectively. The polymers used for preparing the masks in this study were polycaprolactone (PCL), poly(vinyl chloride) (PVC) and polycarbonate (PC). The PVC compound was prepared by mixing in a two roll mill using di-2-ethylhexyl phthalate (DEHP) as a plasticizer. The concentration of
DEHP was varied from 8 to 25 phr. Eusorb UV-P was use as a radiation stabilizer, varied from 0.51.5 phr. From the results, it was found that the optimum PVC compound was obtained by using 1825
phr of DEHP and 0.5 phr of Eusorb UV-P. The PC compound was prepared by a twin-screw extruder using trioctyl trimellitate (TOTM) as a plasticizer. The concentration of TOTM was varied
from 20 to 80 phr. Eusorb UV-P was also used as a radiation stabilizer, varied from 0.5-1.5 phr. From the results, it was found that the optimum PC compound is that obtained by using 75-80 phr of
TOTM and 0.5 phr of Eusorb UV-P. Finally, the PCL compound was prepared by a twin-screw extruder using 25 phr of high density polyethylene, 73 phr of PCL, 2 phr of triallyl cyanurate as a
crosslink enhancer, 2 phr ofIrganox 1010 antioxidant, and 0.5 phr Eusorb UV-P.