The present disclosure is directed to a thermoset composition comprising a low molecular weight polytrimethylene ether glycol. This disclosure is further directed to an antimicrobial coating composition, an antimicrobial coating layer, an antimicrobial adhesive, or an antimicrobial sealant formed from the thermoset composition comprising the low molecular weight polytrimethylene ether glycol. The thermoset compositions can be used as interior and exterior top coats, basecoats, primers, primer surfacers, primer fillers, adhesives or sealants. The disclosure is particularly directed to a thermoset composition comprising components derived from renewable resources.