Abstract:
This research studied the effect of thermal and QUV accelerated aging on anti-bacterial
performance and physical and mechanical properties of polyethylene (PE) and polyvinyl chloride
(PVC) doped with silver colloid by varying dosage of silver colloid, type of bacteria, contact time,
and aging time. The antimicrobial performance was evaluated through inhibition zone and plate
count agar (PCA) method against Escherichia coli (E. coli) and Staphylococcus aureus (s. aureus).
The experimental results suggested that PE and PVC added with silver coIloid did not show
inhibition zone. On the other hand. the PCA method indicated that the percentage reduction of
bacteria increased with increasing silver colloid loading. The percentage reduction of bacteria of PE
doped with 1,000 ppm nano-silver colloid was 84.4% at the contact time of 210 min and that of
PVC doped with 200 ppm nano-silver colloid was 99.9% at the contact time of 150 min. The
bacteria killing effect was more effective for E. coli than S. aureus. For thermal aging effect,
increasing aging time did not affect the antibacterial performance. For QUV aging effect, the
percentage reduction of bacteria for PE doped with silver colloid of 100 and of 1,000 ppm and for
PVC doped with silver colloid of 100 ppm decreased with increasing QUV aging time. The
lightness of PVC. was less than PE. The addition of silver colloid into PVC did not affect the
lightness, but the lightness decreased with increasing silver colloid into PE. After UV exposure, the
contact angle values of PE and PVC doped with silver colloid decreased with increasing aging time.
After UV radiation aging, the modulusand hardness increased while tensile strength and elongation
at break decreased with increasing UV aging time. However, the silver colloid loading did not affect
the mechanical properties of PE and PVC in all aging times.