High‐density polyethylene (HDPE) and polypropylene (PP) blends of varying composition have been evaluated in an effort to establish a mixing rule for melt flow index (MFI). In addition, a previously established relationship between MFI and for linear polymers was also evaluated for these blends. It was found that a parabolic relationship existed between the composition (by weight fraction) and MFI and that the MFI and relationship held for this set of polymeric materials. Additionally, all properties and relationships were evaluated over five extrusion cycles, which showed minimal to no deviations over the five cycles.

This paper presents a novel approach to in-line chemical gas flow monitoring, employing a high-Q RF resonator coated with a polymeric sensing material. The polymeric sensing materials employed are OV-275 and P25DMA doped with 20% NiO. These materials are known to be responsive against various VCOs, and are individually coated on the post of a combline cavity resonator to help functionalize the sensor against specific analytes. The input of the resonator was deliberately designed to achieve the minimal loading to maximize the loaded Q of the resonator, thereby improving its sensitivity near its f₀. The OV-275 sensor demonstrates sensitivity of 2.332 mdB/ppm and 0.348 mdB/ppm to acetone and benzene exposure, respectively. Similarly, the P25DMA sensor has a sensitivity of 0.199 mdB/ppm and 0.764 mdB/ppm to acetone and benzene, respectively.