A polymeric composition comprised of poly(methylmethacrylate) (PMMA) and polylactic acid (PLA) having a surface charge potential of at least about 50 volts in the absence of any other charge enhancing component may be made by melt blending PMMA and PLA, extruding the melt blend through a die and cooling at a rate through Tg of the PLA of at 10° C./min to 1000° C./second. The polymeric composition may be made by melt blowing into a nonwoven fabric. The nonwoven fabric may be charged to a surface potential of at least about 50 electron volts. Such filters may have greater than 95% efficiency at a pressure drop of less than 2 mm Hg even after being exposed to high temperatures (~70° C.) for an hour or more.