Photochemical method to eliminate oxygen inhibition of free radical polymerizations
AssigneeUniversity of Iowa Research Foundation
InventorsAlec Scranton, Lijing Gou
Life of this patent
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Abstract
Compositions and methods for addressing oxygen inhibition in free radical polymerization systems and determination of oxygen content in a monomer or oligomer. The compositions used include a singlet oxygen generator and a singlet oxygen trapper. Addition of the generator and trapper resulting in removal of oxygen can occur before polymerization or essentially simultaneously with polymerization. Determination of oxygen content comprises monitoring the concentration changes from the reaction of the singlet oxygen trapper with the oxygen in the system.
Claims31
A method for addressing oxygen inhibition in a free radical polymerization system comprising
- (a) adding
- (i) a singlet oxygen generator,
- (ii) a singlet oxygen trapper,
- (iii) a free radical polymerizable monomer or oligomer, and
- (iv) an initiator, wherein the singlet oxygen trapper does not react with the free radical polymerizable monomer or oligomer;
- (b) illuminating the system at a wavelength which activates the singlet oxygen generator;
- and
- (c) initiating photopolymerization of the monomer or oligomer.
A composition for addressing oxygen inhibition in a free radical photopolymerization system/improved free radical photopolymerization comprising
- (a) a singlet oxygen generator and
- (b) a singlet oxygen trapper, wherein the singlet oxygen trapper does not react with a free radical polymerizable monomer or oligomer.
A method of free radical polymerization comprising
- (a) adding
- (i) a singlet oxygen generator,
- (ii) a singlet oxygen trapper;
- (iii) a monomer or oligomer, and
- (iv) an initiator, wherein the singlet oxygen trapper does not react with the monomer or oligomer;
- (b) pre-illuminating (i)–(iv) wherein the wavelength excites the singlet oxygen generator;
- (c) initiating photopolymerization of the monomer or oligomer.
A method of free radical polymerization comprising
- (a) adding
- (i) a singlet oxygen generator,
- (ii) a singlet oxygen trapper,
- (iii) a monomer or oligomer,
- (iv) a photoinitiator, wherein the singlet oxygen trapper does not react with the monomer or oligomer;
- (b) illuminating by a first wavelength and a second wavelength wherein the first wavelength excites the singlet oxygen generator and wherein the second wavelength is absorbed by the photoinitiator whereby polymerization of the monomer or oligomers is initiated.
A method comprising
- (a) adding
- (i) a singlet oxygen generator,
- (ii) a singlet oxygen trapper,
- (iii) a monomer or oligomer, wherein the singlet oxygen trapper does not react with the monomer or oligomer;
- (b) consuming oxygen by activating the singlet oxygen generator in the presence of molecular oxygen to form singlet oxygen whereby the singlet oxygen trapper consumes the singlet oxygen;
- and
- (c) initiating photopolymerization of the monomer or oligomer.
A method of increasing the rate of free radical polymerization in an oxygen-containing environment comprising
- (a) adding a singlet oxygen generator and a singlet oxygen trapper to a free radical polymerization system wherein the free radical polymerization system comprises monomer or oligomer and initiator, and wherein the singlet oxygen trapper does not react with the monomer or oligomer,
- (b) illuminating the system at a wavelength which activates the singlet oxygen generator,
- (c) initiating the photopolymerization of the monomer or oligomer.
A method of avoiding an inhibition period in free radical polymerization in an oxygen-containing environment comprising
- (a) adding a singlet oxygen generator and a singlet oxygen trapper to a free radical polymerization system wherein the free radical polymerization system comprises monomer or oligomer and initiator, and wherein the singlet oxygen trapper does not react with the monomer or oligomer,
- (b) illuminating the system at a wavelength which activates the singlet oxygen generator,
- (c) initiating the photopolymerization of the monomer or oligomer.
A method of increasing primary polymer chain length in free radical polymerization in an oxygen-containing environment comprising
- (a) adding a singlet oxygen generator and a singlet oxygen trapper to a free radical polymerization system wherein the free radical polymerization system comprises monomer or oligomers and initiator, and wherein the singlet oxygen trapper does not react with the monomer or oligomer,
- (b) illuminating the system at a wavelength which activates the singlet oxygen generator, and
- (c) initiating the photopolymerization of the monomer or oligomer.
A method of determining oxygen concentration in a monomer or oligomer comprising
- (a) adding
- (i) a singlet oxygen generator,
- (ii) a singlet oxygen trapper,
- (iii) a monomer or oligomer, wherein the singlet oxygen trapper does not react with the monomer or oligomer;
- (b) consuming oxygen by activating the singlet oxygen generator in the presence of molecular oxygen to form singlet oxygen whereby the singlet oxygen trapper consumes the singlet oxygen;
- (c) monitoring a change in concentration of singlet oxygen trapper until the concentration of singlet oxygen trapper is stable;
- and
- (d) correlating the stable concentration of singlet oxygen trapper with the concentration of oxygen.
Dependencies are inferred from the claim text.