POLYMERS, COMPOSITIONS AND METHOD FOR MANUFACTURING AN ARTICLE BY 3D PRINTING

Abstract

The present invention relates to polyetherimide polymers which can for example be used in lithographic processes for the photofabrication of three-dimensional (3D) articles. The invention further relates to compositions including these polyetherimide polymers. Still further, the invention relates to lithographic methods to form 3D articles or objects that incorporate the aforementioned polymer compositions.

Claims

1. A polyetherimide (PEI) polymer (P1) comprising: recurring units R.sub.PEI according to formula (M): ##STR00016## at least one group of formula (L1) to (L4): ##STR00017## wherein Ar is independently from each other a trivalent aromatic moiety selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; Ar′ is a tetravalent aromatic moiety selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; each R.sub.1 is independently H or an alkyl; R is selected from the group consisting of substituted and unsubstituted divalent organic radicals, T can either be
—O— or —O-Q-O— wherein the divalent bonds of the —O— or the —O-Q-O— group are in the 3,3′, 3,4′, 4,3′, or the 4,4′ positions, wherein Q is selected from the group consisting of substituted and unsubstituted divalent organic radicals, each Z is independently selected from the group consisting of: O—(CH.sub.2).sub.k—O—CO—CH═CHR.sub.4, with k being from 1 to 20; and R.sub.4 being H or an alkyl; O—(CH.sub.2).sub.p—Ar—CR.sub.5═CHR.sub.6 or O—(CH.sub.2).sub.p—OAr—CR.sub.5═CHR.sub.6, wherein p is from 0 to 20; Ar comprises one or two aromatic or heteroaromatic rings; R.sub.5 and R.sub.6 are H, an alkyl, a phenyl or a COOR.sub.7 with R.sub.7 being H or an alkyl; O—(CH.sub.2).sub.q—CH═CHR.sub.8 with q being from 0 to 20; and R.sub.8 being H or an alkyl; O—(CH.sub.2).sub.r—O—CH═CHR.sub.9 with r being from 0 to 20; and R.sub.9 being H or an alkyl; ##STR00018##  with s being from 0 to 20; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.k—O—CO—CH═CHR.sub.4, with k and R.sub.4 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.p—Ar—CR.sub.5═CHR.sub.6, with p, Ar, R.sub.5 and R.sub.6 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.p—OAr—CR.sub.5═CHR.sub.6 with p, Ar, R.sub.5 and R.sub.6 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.q—CH═CHR.sub.8, with q and R.sub.8 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.9—O—CH═CHR.sub.9, with r and R.sub.9 as above-defined; ##STR00019##  with s as above-defined; wherein R.sub.a, R.sub.b, and R.sub.c are independently H or an alkyl.

2. The PEI polymer (P1) of claim 1, comprising at least 50 mol. % (based on the total number of moles in the polymer) of recurring units of formula (M).

3. The PEI polymer (P1) of claim 1, wherein Z is O—(CH.sub.2).sub.k—O—CO—CH═CHR.sub.4, with k being from 2 to 6 and R.sub.4 being H or CH.sub.3.

4. The PEI polymer (P1) of claim 1, wherein the PEI polymer (P1) has a number average molecular weight (Mn) (as measured by gel permeation chromatography (GPC) using N,N-dimethylformamide as a mobile phase, with polystyrene standards) of: less than 100,000 g/mol; and/or more than 1,000 g/mol.

5. A formulation (F), comprising: the PEI polymer (P1) of claim 1; and one solvent; optionally one photoinitiator; optionally one blocker.

6. The formulation (F) of claim 5, wherein: the solvent is selected from the group consisting of ortho-dichlorbenzene 1,2 dichloroethane, m-cresol, chlorobenzene, chloroform, N-methylpyrrolidone (NMP), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO), sulfolane, γ-butyrolactone and γ-valerolactone; the photoinitiator is selected from the group consisting of 2,2-dimethoxy-2-phenylacetophenone (DMPA), Diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide and phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide; and/or the blocker is selected from the group consisting of avobenzone and 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene.

7. A process for preparing the PEI polymer (P1) of claim 1, comprising: a) providing a PEI polymer (P0) of formula R.sub.nR.sub.mN—P—NR.sub.nR.sub.m, wherein P comprises recurring units R.sub.PEI according to formula (M): ##STR00020## wherein R is selected from the group consisting of substituted and unsubstituted divalent organic radicals T can either be
—O— or —O-Q-O— wherein the divalent bonds of the —O— or the —O-Q-O— group are in the 3,3′, 3,4′, 4,3′, or the 4,4′ positions, wherein Q is selected from the group consisting of substituted and unsubstituted divalent organic radicals, b) reacting the PEI polymer (P0) with a compound of formula (I) to (IV): ##STR00021## wherein: Ar is a trivalent aromatic moiety, selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; Ar′ is a tetravalent aromatic moiety selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; X is Cl, Br, F or I; each Z is selected independently from the group consisting of: O—(CH.sub.2).sub.k—O—CO—CH═CHR.sub.4, with k being from 1 to 20; and R.sub.4 being H or an alkyl; O—(CH.sub.2).sub.p—Ar—CR.sub.5═CHR.sub.6 or O—(CH.sub.2).sub.p—OAr—CR.sub.5═CHR.sub.6, wherein p is from 0 to 20; Ar comprises one or two aromatic or heteroaromatic rings; R.sub.5 and R.sub.6 are H, an alkyl, a phenyl or a COOR.sub.9 with R.sub.7 being H or an alkyl; O—(CH.sub.2).sub.q—CH═CHR.sub.8 with q being from 0 to 20; and R.sub.8 being H or an alkyl; O—(CH.sub.2).sub.r—O—CH═CHR.sub.9 with r being from 0 to 20; and R.sub.9 being H or an alkyl; ##STR00022##  with s being from 0 to 20; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.k—O—CO—CH═CHR.sub.4, with k and R.sub.4 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.p—Ar—CR.sub.5═CHR.sub.6, with p, Ar, R.sub.5 and R.sub.6 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.p—OAr—CR.sub.5═CHR.sub.6 with p, Ar, R.sub.5 and R.sub.6 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.q—CH═CHR.sub.8, with q and R.sub.8 as above-defined; O.sup.−, NR.sub.aR.sub.bR.sub.cH.sup.+—(CH.sub.2).sub.r—O—CH═CHR.sub.9, with r and R.sub.9 as above-defined; ##STR00023##  with s as above-defined; wherein R.sub.a, R.sub.b, and R.sub.c are independently H or an alkyl, in the presence of a polar aprotic solvent and an organic base.

8. The process of claim 7, wherein the solvent is selected from the group consisting of chlorobenzene, chloroform, N-methylpyrrolidone (NMP), N,Ndimethylformamide (DMF), N,N-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone, tetrahydrofuran (THF), dimethyl sulfoxide (DMSO) and sulfolane, and γ-butyrolactone and γ-valerolactone the organic base is selected from the group consisting of pyridine and alkylamine.

9. A process for preparing the PEI polymer (P1) of claim 1, comprising: a) providing a PEI polymer (P0) of formula R.sub.n—R.sub.mN—P—NR.sub.nR.sub.m, wherein P comprises recurring units R.sub.PEI according to formula (M): ##STR00024## wherein each R.sub.n and R.sub.m is independently H or an alkyl; R is selected from the group consisting of substituted and unsubstituted divalent organic radicals T can either be
—O— or —O-Q-O— wherein the divalent bonds of the —O— or the —O-Q-O— group are in the 3,3′, 3,4′, 4,3′, or the 4,4′ positions, wherein Q is selected from the group consisting of substituted and unsubstituted divalent organic radicals, b) reacting the PEI polymer (P0) with a compound of formula (V) to (VIII): ##STR00025## wherein: Ar is a trivalent aromatic moiety, selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; Ar′ is a tetravalent aromatic moiety selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; X is OH, Cl, Br, F or I; c) reacting the polymer obtained in step b) with a compound selected from the group consisting of: NR.sub.aR.sub.bR.sub.c—(CH.sub.2).sub.k—O—CO—CH═CHR.sub.4, with k and R.sub.4 as above-defined, NR.sub.aR.sub.bR.sub.c—(CH.sub.2).sub.p—Ar—CR.sub.5═CHR.sub.6, with p, Ar, R.sub.5 and R.sub.6 as above-defined, NR.sub.aR.sub.bR.sub.c—(CH.sub.2).sub.p—OAr—CR.sub.5═CHR.sub.6 with p, Ar, R.sub.5 and R.sub.6 as above-defined, NR.sub.aR.sub.bR.sub.c—(CH.sub.2).sub.q—CH═CHR.sub.8, with q and R.sub.8 as above-defined, NR.sub.aR.sub.bR.sub.c—(CH.sub.2).sub.r—O—CH═CHR.sub.9, with r and R.sub.9 as above-defined, ##STR00026##  with s as above-defined, wherein R.sub.a, R.sub.b, and R.sub.c are independently H or an alkyl.

10. A method for manufacturing a three-dimensional (3D) article with an additive manufacturing system, comprising: providing a formulation (F) according to claim 5, printing layers of the three-dimensional (3D) article from the formulation (F), optionally, curing the 3D article at a temperature ranging from 50 to 450° C.

11. The method of claim 10, wherein the step of printing comprises irradiating the polymer composition with light.

12. A three-dimensional (3D) article or object obtained, at least in part, by the method of claim 10.

13. The 3D article or object of claim 12, comprising: recurring units R.sub.PEI according to formula (M): ##STR00027## at least one group of formula (K): ##STR00028## wherein Ar′ is a tetravalent aromatic moiety selected from the group consisting of a substituted or unsubstituted, saturated, unsaturated or aromatic monocyclic and polycyclic group having 5 to 50 carbon atoms; T can either be
—O— or —O-Q-O— wherein the divalent bonds of the —O— or the —O-Q-O— group are in the 3,3′, 3,4′, 4,3′, or the 4,4′ positions, wherein Q is selected from the group consisting of substituted and unsubstituted divalent organic radicals.

14. A method for the manufacture of 3D objects, the method comprising printing the polymer (P1) according to claim 1, the polymer (P1) in a formulation with one solvent, optionally, one photoinitiator, and optionally one blocker, alone or in combination with other components by stereolithography (SLA), direct ink writing (DIW), digital light processing (DLP), or inkjet process.

15. A method for coating an article, the method comprising coating the article with the polymer (P1) according to claim 1, the polymer (P1) in a formulation with one solvent, optionally, one photoinitiator, and optionally one blocker, alone or in combination with other components.

16. The PEI polymer (P1) of claim 1, wherein R is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00029## where Y is selected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4; and Q is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00030## where Y is selected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4.

17. The process of claim 7, wherein R is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00031## where Y is selected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4, and Q is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00032## where Y is elected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4.

18. The process of claim 9, wherein R is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00033## where Y is elected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4, and Q is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00034## where Y is selected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4.

19. The 3D article or object of claim 12, wherein Q is selected from the group consisting of: (a) aromatic hydrocarbon radicals having 6 to 50 carbon atoms and halogenated derivatives thereof; (b) linear or branched alkyl radicals having 2 to 20 carbon atoms; (c) cycloalkyl radicals having 3 to 24 carbon atoms; and (d) divalent radicals of formula (IX): ##STR00035## where Y is selected from the group consisting of alkyl having from 1 to 6 carbon atoms, perfluoroalkyl having from 1 to 6 carbon atoms, cycloalkyl having from 4 to 8 carbon atoms, alkylidenes having from 1 to 6 carbon atoms, cycloalkylidenes having from 4 to 8 carbon atoms, —O—, —S—, —C(O)—, —SO.sub.2— and —SO—, and R″ is selected from the group consisting of hydrogen, halogen, alkyl, alkenyl, alkynyl, aryl, ether, thioether, carboxylic acid, ester, amide, imide, alkali earth metal sulfonate, alkaline earth metal sulfonate, alkyl sulfonate, alkali earth metal phosphonate, alkaline earth metal phosphonate, alkyl phosphonate, amine and quaternary ammonium and i, for each R″, is independently zero or an integer ranging from 1 to 4.

Description

EXAMPLES

[0220] A PEI polymer (P1) and corresponding PEI polymer (P2) according to the present invention were prepared and characterized.

[0221] Molecular Weight (Mn, Mw, Mz and Mz+1)

[0222] The molecular weights were measured by gel permeation chromatography (GPC), using N,N-dimethylformamide as a mobile phase. Two 5μ mixed D columns with guard column from Agilent Technologies were used for separation. An ultraviolet detector of 254 nm was used to obtain the chromatogram. A flow rate of 1.5 ml/min and injection volume of 20 μL of a 0.2 w/v % solution in mobile phase was selected. Calibration was performed with 12 narrow molecular weight polystyrene standards (Peak molecular weight range: 371,000 to 580 g/mol). The number average molecular weight Mn, weight average molecular weight Mw, higher average molecular weight Mz and Mz+1, were reported.

Example 1. Synthesis of PEI Polymer (P1-A)

[0223] This example demonstrates the synthesis of a polymer (P1-A), comprising recurring units R.sub.PEI according to Scheme 1.

##STR00014##

[0224] Formation of the Reactants Amine-PEI and PDMA-HEA (I-A)

[0225] The Amine-PEI (polymer P0-A) was synthetized as follows:

[0226] In a 100-mL 3-neck flask (equipped with a mechanical stirrer, a Dean-Stark trap wrapped in heat tape at 110° C., a condenser (above the dean-Stark trap), and a nitrogen gas inlet/outlet, and external thermocouple with oil bath), 1,3-bis[N-(4-chlorophthalimido)]benzene (11.0841 g), 4,4′-biphenol (5.2290 g), m-aminophenol (0.4685 g), and K.sub.2CO.sub.3 (3.6825 g) were suspended in mixture of NMP (22.29 g), toluene (13.66 g) and sulfolane (60.21 g) for a 19.5 wt % solids solution. The mixture was heated for 1 h at 140° C. and then heated for 10 h at 210° C. with stirring (160 rpm) and medium nitrogen flow. The solution was cooled to 60° C. the solution was coagulated in a blender containing 500 mL of de-ionized water which gave rise to a grey precipitate. The solid material collected was then repeatedly washed with hot H.sup.2O (3×500 mL), filtered, and then washed with methanol (3×500 mL). The final solid material collected via filtration was then dried in a vacuum oven (45° C., 25 inHg) for 72 h to yield 11.54 g of a light grey solid.

[0227] The PDMA-HEA diacid chloride (I-A) (PMDA-HEA-Cl, Mw: 455.24 g/mol) was synthesized according to methods reported in the literature. Reference can be made in particular to Hedge et al. “3D Printing All-Aromatic Polyimides using Mask-Projection Stereolithography: Processing the Nonprocessable” (Adv. Mater. 2017, 29).

[0228] Formation of the PEI Polymer (P1-A)

[0229] A three-neck flask equipped with a gas-inlet, magnetic stir bar and thermocouple was charged with 2.3195 g of Amine-PEI, 0.1 mL of pyridine and 10.5 mL dry NMP. To the flask, 0.2036 g PMDA-HEA (I-A) was then added as single portion and then left stirring at room temperature for 4 h. After mixing the solution was coagulated into 500 mL MeOH and washed MeOH (500 mL×3) with heavy agitation with each wash. The precipitant was collected under vacuum filtration and dried under reduced pressure (25 inHg) at 25° C. for 48 h. Yield 2.4456 g

Example 2. Synthesis of PEI Polymer (P2-A)

[0230] This example demonstrates the synthesis of a PEI polymer (P2-A), according to Scheme 2.

##STR00015##

[0231] A tube furnace was charged 506.7 mg of polymer P1-A and was purged for 20 min under a flow of N.sub.2. A flow of N.sub.2 kept until the sample was taken out of the furnace. After the purge, the tube was then heated at 250° C. for 17 min. After heating, the tube was allowed to cool to room temperature (˜1.5 h) and the sample was removed from the furnace.

Example 3. Characterization of the PEI Polymers (P1-A) and (P2-A)

[0232] The different polymers were characterized by GPC to determine molecular weights (Mn & Mw) and polydispersity index (PDI). The results are summarized in Table 1.

TABLE-US-00001 TABLE 1 Mw Mn Mw/Mn Mz Mz + 1 Mz/Mw Amine PEI 4,980 2,718 1.83 7,972 11,383 1.60 PEI (P1-A) 8,283 4,638 1.79 13,445 19,135 1.62 PEI (P2-A) 11,966 5,515 2.17 24,358 40,198 2.04