Abstract: A method of measuring fluid properties of a polymer melt, undergoing shear and/or extensional flow which utilizes fluorescent anisotropy. The method utilizes a polymeric chromophore which includes a bifunctional anthracene that is covalently bonded to polybutadiene. The invention also involves an optical probe which is designed to be inserted into existing temperature and/or pressure probe ports in processing equipment. The probe includes a rotatable polarizer and emission collection fibers.

Abstract: Accurate dynamic pressure data in a changing thermal environment is obtained through the use of a pressure gage formed from polyvinylidene fluoride (PVDF) polymer material. The temperature compensation pressure gage has three major elements: an active PVDF transducer which obtains remote pressure readings which are uncorrected for thermal effects; a thermocouple having a short rise time allowing an output thermal signal which dynamically responds to changing thermal conditions; and a compensation amplifier circuit receiving the uncorrected pressure readings and the dynamic thermal signal and producing an output signal representing accurate pressure data which is corrected for changing thermal conditions. Also disclosed are the details of making an active PVDF transducer.

Abstract: A transducer, and method for making it, comprising a composite film for sing pressure comprising a pair of film sandwiches, each sandwich comprising a poled polymeric films with metallic film electrodes on opposite surfaces. One electrode does not extend quite to the end of the polymer and is considered the "hot" electrode. Two such transducer film sandwiches are cemented together with the hot electrodes in contact with each other, the center wire from a coaxial cable being in contact with and between them. The outer electrodes are electrically connected to the shield of the cable and the connection is encapsulated.

Abstract: An optical sensor containing polarizing optical components measures fluorescence anisotropy of fluorescent dyes. The measurement involves the detection of vertical and horizontal components of fluorescent light. Using Glan-Taylor and Wollaston calcite polarizers, both vertical and horizontal components are collected by separate optical fibers and measured simultaneously using a two-channel photon counter. One application of this sensor is the measurement of molecular orientation during polymer processing. Two sensor head designs are described, one of which fits into the 1/2 inch instrumentation port in polymer processing machines. To carry out process monitoring, a fluorescent dye is mixed with a polymer resin at approximately 10 ppm by weight concentration. Dyes which have geometrical asymmetry in their molecular structure or are covalently bonded to the polymer molecule are usually used. The anisotropy measurement yields information about the orientation of the dye molecule in an oriented medium.