Polypropylene Compositions with Enhanced Microwave Absorption and Reduced Microwave Reflection

A composition comprising a thermoplastic resin, wherein the thermoplastic resin comprises:

• a polypropylene polymer;
• and
• from about 0.15 wt % to about 4.75 wt % of a filler comprising carbon nanotubes, wherein the carbon nanotubes have an average diameter of about 5-15 nanometers (nm), a surface area of at least about 100 square meters per gram (m2/gr), and a volume resistivity of 10−3 Ohm·centimeters (Ohm·cm) or lower,
• wherein the composition exhibits a volume electrical resistivity between 2.0E+14 Ohm·cm and 1.0E+03 Ohm·cm when measured according to ASTM D257,
• wherein a molded sample of the composition having a thickness of from about 3.1 millimeters (mm) to about 3.3 mm exhibits a percent Absorbed Power measured in Transmission mode of at least 65% when observed according to a Free Space method at frequencies of from about 75 GHz to about 110 GHz, and
• wherein the combined weight percent value of all components does not exceed 100 wt. %, and all weight percent values are based on the total weight of the composition.