Antimicrobial Polyethylene through Melt Compounding with Quaternary Ammonium Salts

Table 3

Antibacterial activity of modified PE samples containing 5 wt-% quat (after leaching) against S. aureus, E. coli, and P. aeruginosa. Bacterial survival in tap water was variable; therefore only experiments where at least 50% of the bacteria survived in the suspension on pure PE were considered for this table. ++: most bacteria are dead; +: proportion of dead bacteria clearly increased compared to PE reference; +/−: different results with different samples; −: proportion of dead bacteria not increased compared to PE reference.

	Antibacterial activity
	S. aureus	E. coli	P. aeruginosa
1	++	++	n.a.
2	−	n.a.	n.a.
3	−	−	n.a.
4	++	+/−	++
5	−	n.a.	−
6	++	++	++
7	+	+	++
9	+	−	++

amount of quat 8 available was not sufficient for a thorough investigation; however, in preliminary experiments it was found to have good antibacterial activity against S. aureus.