# US 11,078,302 B2 · Polymerization methods

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- Number: US 11,078,302 B2
- Document ID: US11078302B2
- Status: Granted
- Kind: B2
- Application number: 16/407,756
- Filed: 2019-05-09
- Published: 2019-11-14
- Granted: 2021-08-03
- Earliest claimed: 2018-05-10
- Assignees: North Carolina State University
- Applicants: North Carolina State University
- Inventors: Felix N. Castellano; Nancy Awwad; Anh Thy Bui
- Web page: https://patentgrep.com/patent/US11078302B2

## CPC

- C08F 2/48: by ultraviolet or visible light
- B01J 31/1815: {with more than one complexing nitrogen atom, e.g. bipyridyl, 2-aminopyridine}
- B01J 35/39: Photocatalytic properties
- B29C 64/291: for operating globally, e.g. together with selectively applied activators or inhibitors
- B33Y 70/00: Materials specially adapted for additive manufacturing
- C08F 20/18: with acrylic or methacrylic acids
- C08F 20/34: Esters containing nitrogen {, e.g. N,N-dimethylaminoethyl (meth)acrylate}
- C08F 20/40: Esters of unsaturated alcohols {, e.g. allyl (meth)acrylate}
- C08F 120/14: Methyl esters {, e.g. methyl (meth)acrylate}
- C08F 220/20: of polyhydric alcohols or phenols {, e.g. 2-hydroxyethyl (meth)acrylate or glycerol mono-(meth)acrylate}
- B01J 2531/025: Ligands with a porphyrin ring system or analogues thereof, e.g. phthalocyanines, corroles
- B01J 2531/26: Zinc
- B33Y 10/00: Processes of additive manufacturing
- B33Y 80/00: Products made by additive manufacturing
- C08F 222/103: {of trialcohols, e.g. trimethylolpropane tri(meth)acrylate}
- C08F 2438/03: Use of a di- or tri-thiocarbonylthio compound, e.g. di- or tri-thioester, di- or tri-thiocarbamate, or a xanthate as chain transfer agent, e.g . Reversible Addition Fragmentation chain Transfer [RAFT] or Macromolecular Design via Interchange of Xanthates [MADIX]
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING

## Abstract

Disclosed herein are methods of forming (co)polymers from polymerizable compositions, the methods comprising irradiating the polymerizable compositions with light, wherein the polymerizable compositions comprise a polymerization initiator having an absorption band and exhibiting triplet-triplet annihilation up-conversion and a monomer. Also disclosed herein are methods of additive manufacturing using the methods of forming (co)polymers described herein.

## Claims

### Claim 1

A method of forming a (co)polymer from a polymerizable composition, the method comprising:
irradiating the polymerizable composition with light,
wherein the polymerizable composition comprises:
a polymerization initiator having an absorption band and exhibiting triplet-triplet annihilation up-conversion; and
a monomer; and
wherein irradiating the polymerizable composition causes the polymerization initiator to undergo triplet-triplet annihilation up-conversion to induce polymerization of the monomer.

### Claim 2 (depends on 1)

The method of claim 1, further comprising depleting oxygen from the polymerizable composition prior to irradiation.

### Claim 3 (depends on 1)

The method of claim 1, wherein the polymerization initiator comprises a closed-shell metalloporphyrin complex.

### Claim 4 (depends on 1)

The method of claim 1, wherein the polymerization initiator comprises Zn(II) tetraphenylporphyrin (ZnTPP); meso-tetraphenylporphyrin (TPP); 5,10,15,20-tetraphenyl-21H,23H-porphine nickel(II) (NiTPP); 5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphine cobalt(II) (CoTMPP); 5,10,15,20-tetrakis(4-methoxyphenyl)-21H,23H-porphine iron(III) chloride (FeTMPP); palladium(II) octaethylporphyrin (PdOEP); or a combination thereof.

### Claim 5 (depends on 1)

The method of claim 1, wherein the monomer comprises an ethylenically unsaturated monomer.

### Claim 6 (depends on 1)

The method of claim 1, wherein the monomer comprises trimethylolpropane triacrylate (TMPTA), ethoxylated trimethylolpropane triacrylate (EO-TMPTA), tris(2-hydroxyethyl) isocyanurate triacrylate (THEITA), (meth)acrylate, methyl (meth)acrylate, or a combination thereof.

### Claim 7 (depends on 1)

The method of claim 1, wherein the light has an energy that is less than the absorption band of the polymerization initiator.

### Claim 8 (depends on 1)

The method of claim 1, wherein the light irradiating the polymerizable composition has an energy that does not substantially overlap with the absorption band of the polymerization initiator.

### Claim 9 (depends on 1)

The method of claim 1, wherein the light irradiating the polymerizable composition has an energy that at least partially overlaps with the absorption band of the polymerization initiator.

### Claim 10 (depends on 1)

The method of claim 1, wherein the light comprises visible light.

### Claim 11 (depends on 1)

The method of claim 1, wherein the light has a power of 300 mW or less.

### Claim 12 (depends on 1)

The method of claim 1, wherein the polymerization initiator comprises a metalloporphyrin complex having a Q-band and the light irradiating the polymerizable composition excites the Q-band of the metalloporphyrin complex.

### Claim 13 (depends on 1)

The method of claim 1, wherein irradiating the polymerizable composition causes the polymerization initiator to produce a radical and wherein the radical induces polymerization of the monomer.

### Claim 14 (depends on 1)

The method of claim 1, wherein irradiating the polymerizable composition causes the polymerization initiator to undergo homomolecular triplet-triplet annihilation up-conversion.

### Claim 15 (depends on 1)

The method of claim 1, wherein irradiating the polymerizable composition causes the polymerization initiator to undergo heteromolecular triplet-triplet annihilation up-conversion and wherein the polymerization initiator comprises a sensitizer and an emitter.

### Claim 16 (depends on 1)

The method of claim 1, wherein the polymerizable composition further comprises a Reversible Addition-Fragmentation chain Transfer (RAFT) agent.

### Claim 17 (depends on 16)

The method of claim 16, wherein the monomer comprises at least one acrylate end group, wherein the polymerization initiator comprises palladium(II) octaethylporphyrin (PdOEP), wherein the RAFT agent comprises a thiocarbonylthio compound, or a combination thereof.

### Claim 18 (depends on 16)

The method of claim 16, wherein the RAFT agent comprises 2-(dodecylthiocarbonothioylthio)propionic acid (DTPA).

### Claim 19

A method of forming a (co)polymer from a polymerizable composition, the method comprising:
irradiating the polymerizable composition with light,
wherein the polymerizable composition comprises:
a polymerization initiator having an absorption band and exhibiting triplet-triplet annihilation up-conversion;
a reversible addition-fragmentation chain transfer (RAFT) agent; and
a monomer; and
wherein irradiating the polymerizable composition causes the polymerization initiator to form a radical that induces reversible addition-fragmentation chain transfer (RAFT) polymerization of the monomer.

### Claim 20 (depends on 1)

A method of forming an object via additive manufacturing, the method comprising:
irradiating a first quantity of a polymerizable composition on a substrate to induce polymerization of a monomer into a first layer on the substrate using the method of claim 1; and
forming at least one additional layer on the first layer by irradiating at least a second quantity of the polymerizable composition to induce polymerization of the monomer into the at least one additional layer on the first layer using the method of claim 1, thereby forming the object.

### Claim 21 (depends on 1)

A method of producing a three-dimensional structure using additive manufacturing, the method comprising forming the three-dimensional structure on a layer-by-layer basis using the method of claim 1.

### Claim 22 (depends on 1)

An article of manufacture comprising a (co)polymer formed using the method of claim 1, wherein the article of manufacture comprises a photonic crystal, a microfluidic device, a photovoltaic, a photochromic display, a compact disc, a dental (co)polymer, an adhesive, an automotive part, plastic flooring, a thin film coating, a disposable syringe, an intravenous bag, sterile packaging for a medical instrument, a joint replacement, a tissue scaffold, a contact lens, a fiber optic, a transdermal patch, a microneedle array, or a combination thereof.