Robert W Lowry

US Patent:

51517485, Sep 29, 1992

Filed:

Aug 7, 1990

Appl. No.:

7/563762

Inventors:

Anthony J. Bur - Rockville MD
Robert E. Lowry - Falls Church VA
Steven C. Roth - Frederick MD
Charles L. Thomas - Philadelphia PA
Francis W. Wang - Gaithersburg MD

Assignee:

The United States of America as represented by the Secretary of Commerce - Washington DC

International Classification:

G01N 2164

US Classification:

356 32

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.

US Patent:

55980058, Jan 28, 1997

Filed:

Feb 15, 1995

Appl. No.:

8/389823

Inventors:

Francis W. Wang - Gaithersburg MD
Robert E. Lowry - Falls Church VA
King-Fu Lin - Taipei, TW

Assignee:

The United States of America as represented by the Secretary of the
Commerce - Washington DC

International Classification:

G01N 2164
G01N 3344

US Classification:

2504591

Abstract:

The change in the peak fluorescence wavelength of a small amount of a fluorescent compound, i. e. , a fluorophore, which has been dissolved in a polymerizing material or a thermoplastic polymer is used to determine the extent of cure or solidification, respectively. The measured wavelength-shift can either be compared with a previously determined correlation to obtain an absolute value for the extent of cure, or can be utilized to compare or maintain an acceptable extent of cure throughout a manufacturing or a clinical process. Similarly, in the processing of a thermoplastic polymer by injection molding, the measured wavelength shift can either be compared with a previously determined correlation to obtain an absolute value for the temperature of the polymer, or can be utilized to adjust the injection molding cycle so that the mold is opened at the optimum times. The fluorophores used in the method are preferably selected from a class of fluorophores comprising alpha, omega substituted linear alkenes having an electron accepting group attached at the alpha position and an electron donating group attached at the omega position.