Abstract:
Malaria is still a major tropical disease, with Africa particularly burdened. It has been
proposed that outdoor protection could aid substantially in reducing the malaria incidence rate
in rural African communities. Recently, melt-spun polyolefin fibers containing mosquito repellents
have been shown to be promising materials to this end. In this study, the incorporation of
N,N-Diethyl-3-methylbenzamide (DEET)—a popular and widely available mosquito repellent—in
commercially available, amorphous poly(D,L-lactic acid) (PDLLA) is investigated with the aim of
producing biodegradable mosquito-repelling filaments with a reduced environmental impact. It is
shown to be possible to produce macroscopically stable PDLLA-DEET compounds containing up to
20 wt.-% DEET that can be melt-spun to produce filaments, albeit at relatively low take-up speeds. A
critical DEET content allows for stress-induced crystallization during the spinning of the otherwise
amorphous PDLLA, resulting in the formation of -crystals. Although the mechanical integrity of
the filaments is notably impacted by the incorporation of DEET, these filaments show potential as
materials that can be used for Malaria vector control.