Method and apparatus for in situ, non-invasive polymer cure determination
AssigneeBoard of Trustees operating Michigan State University
InventorsGary J. Blanchard, Julie L. Jessop, Alec B. Scranton
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Abstract
A method and apparatus (10) for detection of the degree of cure of a polymer in situ and non-invasively. The method and apparatus uses a solvatochromic probe molecule which upon curing produces a shift in the fluorescence emission spectrum as compared to a liquid polymerizable composition. The method and apparatus is particularly adapted for poly(vinyl) polymers. Preferred solvatochromic probe molecules are oxazones and pyrene.
Claims20
A method for determining a degree of curing of a liquid polymerizable composition to a cured polymer which comprises:
- (a) providing a solvatochromic probe molecule which is a polycyclic aromatic compound in an amount up to about 10.sup.-3 weight percent of the polymerizable composition in a reaction mixture with the liquid polymerizable composition which is curable to the cured polymer, the probe molecule having a first fluorescence emission spectrum in the reaction mixture;
- (b) curing the fluid reaction mixture to produce the cured polymer with measurement of the emission spectrum fluorescence, wherein during the curing to produce the polymer the reaction mixture exhibits a shift in the first fluorescence emission spectrum to a second fluorescence emission spectrum because of the probe molecule;
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- (c) determining the degree of curing of the cured polymer, wherein the shift in the fluorescence is detected beyond a gel point of the polymer.
A method for determining a degree of cure of a polymer which comprises:
- (a) introducing a solvatochromic probe molecule into a reaction mixture which is a liquid polymerizable composition the probe molecule being present in an amount up to about 10.sup.-3 weight percent of the polymerizable composition, wherein the probe molecule has a fluorescence emission spectrum which changes during curing;
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- (b) monitoring the fluorescence emission spectrum of the probe molecule in the reaction mixture during the polymerization, wherein there is a shift in an initial fluorescence emission spectrum of the probe molecule in the reaction mixture over time;
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- (c) comparing a change in the fluorescence emission spectrum to a preceding fluorescence emission spectrum at different times so as to detect the degree of cure, wherein the shift in fluorescence is detected beyond the gel point of the polymer.
Dependencies are inferred from the claim text.