Alkenyl Ether Polyols

Abstract

The invention relates to a method for producing radiation-curable alkenyl ether polyols, to radiation-curable alkenyl ether polyols produced using the method according to the invention, and to the use thereof for the synthesis of radiation-interlinkable oligomers or polymers by means of polyaddition reactions or polycondensation reactions, in particular for the synthesis of radiation-curable polyesters, polyethers, polyurethanes and polyureas, particularly preferably UV-curable polyurethanes. The invention also relates to radiation-curable polyurethane polymers that are obtained by reacting at least one alkenyl ether polyol according to the invention with a polyisocyanate.

Claims

1-14. (canceled)

15. An alkenyl ether polyol of formula (I) or (V) ##STR00036## where R.sub.1 is selected from a divalent organic residue; an at least divalent linear or branched, substituted or unsubstituted, alkyl with 1 to 20 carbon atoms; or a linear or branched, substituted or unsubstituted, heteroalkyl with 1 to 20 carbon atoms and at least one oxygen or nitrogen atom, R.sub.2 is selected from an organic residue; an organic residue with at least one OH group and/or 1 to 1000 carbon atoms; an optionally divalent or polyvalent, linear or branched, substituted or unsubstituted, alkyl with 1 to 20 carbon atoms; or a linear or branched, substituted or unsubstituted, heteroalkyl with 1 to 20 carbon atoms and at least one oxygen or nitrogen atom, R.sub.3 is selected from an organic residue; an organic residue with 1 to 1000 carbon atoms; an optionally divalent or polyvalent, linear or branched, substituted or unsubstituted, alkyl with 1 to 20 carbon atoms; a linear or branched, substituted or unsubstituted, heteroalkyl with 1 to 20 carbon atoms and at least one oxygen or nitrogen atom; a (poly)alkylene glycol of the formula O[CHR.sub.aCH.sub.2O].sub.bR.sub.b, where b is 1 to 100, R.sub.a is H or a C.sub.1-4 alkyl residue, and R.sub.b is OH or ##STR00037## in formula (I), X is O, S, C(O)O, OC(O)O, C(O)OC(O)O, NR.sub.x, NR.sub.xC(O)O, NR.sub.xC(O)NR.sub.x, or OC(O)NR.sub.x, in formula (V), X is O, S, OC(O), OC(O)O, OC(O)OC(O), NR.sub.z, NR.sub.zC(O)O, NR.sub.zC(O)NR.sub.z, or OC(O)NR.sub.z, each R and R is selected independently from among H, C.sub.1-20 alkyl, and C.sub.2-20 alkenyl; or one of R and R is H and the other is C.sub.1-4 alkyl; or both R and R are H, each A, B, and C is independently selected from among CRR, R and R are selected independently from among H, a functional group, an organic residue, and C.sub.1-20 alkyl; or R and R together or with the carbon atom to which they are bonded are an organic residue; or two of R and R that are bonded to neighboring carbon atoms form a bond together in order to form a double bond between the neighboring carbon atoms, is a single or double bond, and if it is a double bond, the C that bonded to R.sub.2 bears only one substituent R or R, m is an integer from 1 to 10, n, p and o are each 0 or an integer from 1 to 10, where n+p+o=1 or 2, s and t are each 0 or an integer from 1 to 10, where s+t=1 or 2, R.sub.x is H, an organic residue, or ##STR00038## and if X is not NR.sub.x where ##STR00039## R.sub.2 has at least one substituent that is selected from among OH and ##STR00040## and R.sub.z is H, an organic residue, or ##STR00041## and if X is not NR.sub.z where ##STR00042## than R.sub.3 has at least one substituent that is selected from among OH and ##STR00043##

16. A radiation-crosslinkable oligomers or polymers that is the reaction product of a mixture comprising at least one alkenyl ether polyol as set forth in claim 15.

17. UV- and EB-curable polyesters, polyethers, polyurethanes, and polyureas that are the reaction product of a mixture comprising at least one alkenyl ether polyol as set forth in claim 15.

18. A UV-curable polyurethane polymer that is the reaction product of a mixture comprising at least one alkenyl ether polyol as set forth in claim 15 and a polyisocyanate.

Description

EXAMPLES

Materials Used:

[0135] 4-hydroxybutyl vinyl ether (HBVE) (BASF) and 3-aminopropyl vinyl ether (APVE) (BASF) were stored over molecular sieve 4 .

Sodium (Merck) was washed in dry diethyl ether and cut into pieces. 1,4-butanediol diglycidyl ether (BDDGE, Sigma-Aldrich, 95%), 2,3-epoxy propanol (glydidol, glycid; Evonik), isopropyl glycidyl ether (IPGE, Raschig), epichlorohydrin (Solvay, 99.8%), isophorone diisocyanate (IPDI) (Merck, 99%), polypropylene glycol (PPG) (Dow Chemical, Voranol 2000 L, 2000 g/mol), 1-heptanol (Acros Organics, 98%), dimethyl tin dineodecanoate (Momentive, Fomrez catalyst UL-28), 4,4-dimethyldiphenyl iodonium hexafluorophosphate (Omnicat 440, IGM 98%), hexamethylenediamine (99%, Merck), tetrabutylammonium bromide (TBAB, 99%, Acros Organics), and sodium hydroxide (Riedel-de-Hen, 99%) were used as received.

Example 1: Synthesis of a Vinyl Ether Polyol (VEOH)

[0136] 139.51 g (1.2 mol) HBVE were readied in a 250 ml round-bottom flask. A dropping funnel with pressure equalization was connected and 24.78 g (0.12 mol) BDDGE readied therein. The entire apparatus was dried in a vacuum and flooded with nitrogen. 7.00 g (0.3 mol) of sodium were added. After the sodium had dissolved completely, BDDGE was added slowly. The temperature was controlled such that it did not exceed 50 C. After the addition of the BDDGE was completed, stirring was performed for a time period of 30 minutes at 50 C. 50 ml of water were added in order to hydrolyze the remaining alcoholate. The product was washed several times with saturated sodium chloride solution and water and reduced in a vacuum in order to remove residual reactant and water. Yield: 76%. .sup.1H-NMR (CDCl.sub.3), xy MHz): (pp)=1.6-1.8 (12H, mid-CH.sub.2 butyl), 2.69 (2H, OH, H/D exchangeable), 3.4-3.55 (16H, CH.sub.2OCH.sub.2), 3.70 (4H, CH.sub.2O-vinyl), 3.94 (2H, CHO), 3.98 (1H, CH.sub.2CHO trans), 4.17 (1H, CH.sub.2CHO cis), 6.46 (1H, CH.sub.2CHO gemi).

Example 2

[0137] 50.58 g (0.5 mol) APVE and 139.44 g (81.2 mol) IPGE were readied in a 250 ml round-bottom flask and heated to reflux. The progressing exothermic reaction was controlled such that a temperature of 175 C. was not exceeded. The reaction was cooled to room temperature, and after IR spectroscopy indicated the conversion of the desired quantity of epoxide, 20 ml of sodium hydroxide (1 mol/l) were added, and the emulsion was heated to 100 C. over a period of 30 min in order to hydrolyze the remaining epoxide residues. The organic phase was washed several times with water and dried under reduced pressure. Yield: 54%. .sup.1H-NMR (CDCl.sub.3, xy MHz): (pp)=1.15 (12H, CH.sub.3), 1.82 (2H, mid-CH.sub.2 propyl), 2.45-2.80 (6H, CH.sub.2N), 3.05-3.30 (2H, OH), 3.40 (4H, CH.sub.2O-isopropyl), 3.59 (2H, CH isopropyl), 3.73 (2H, CH.sub.2O-vinyl), 3.81 (2H, CHOH), 3.99 (1H, CH.sub.2CHO trans), 4.18 (1H, CH.sub.2CHO cis), 6.45 (1H, CH.sub.2CHO gemi).

Example 3

[0138] 58.08 g (0.5 mol) HBVE were readied in a 250 ml round-bottom flask, A dropping funnel with pressure equalization was connected and 7.41 g (0.13 mol) glycidol readied therein. The apparatus was dried in a vacuum and flooded with nitrogen. 3.00 g (0.13 mol) of sodium were added. After the sodium had dissolved completely, glycidol was added slowly. The temperature was controlled such that it did not exceed 50 C. The mixture was stirred over a period of 20 min at 50 C. after the glycidol had been added completely. 50 ml of water were added in order to hydrolyze the remaining alcoholates. The product was washed several times with saturated sodium chloride solution and water and reduced in a vacuum in order to remove any residual reactant and water. Yield: 77%. .sup.1H-NMR (CDCl.sub.3, xy MHz): (pp)=1.6-1.8 (4H, mid-CH.sub.2 Butyl), 3.40-3.75 (2H, CH.sub.2O-vinyl+2H, CH.sub.2O-glyceryl+1H, CHOH+1H, CH.sub.2OH+OCH.sub.2CHOH+2x 1H, OH), 3.85 (1H, CH.sub.2OH), 3.99 (1H, CH.sub.2CHO trans), 4.19 (1H, CH.sub.2CHO cis), 6.47 (1H, CH.sub.2CHO gemi), no remaining epoxide peaks were observed.

Example 4a: Synthesis of 4-Glycidyl Butyl Vinyl Ether (GBVE)

[0139] 116.16 g (1 mol) HBVE and 10.51 (0.05 mmol) tetrabutylammonium bromide were readied in a 1 l round-bottom flask using a dropping funnel with pressure equalization. A mixture of 300 ml toluene and 300 ml 50% aqueous sodium hydroxide solution were added. The reaction mixture was cooled with an ice bath and stirred rapidly. 148.16 g (2 mol) epichlorohydrin were added slowly, and the resulting emulsion was stirred over a period of 16 h at room temperature. The organic phase was washed several times with saturated sodium chloride solution and water. Solvent was removed under reduced pressure, and the product was purified by means of vacuum distillation in order to obtain a colorless liquid. Yield: 66%. .sup.1H-NMR (CDCl.sub.3, 400 MHz): (ppm)=1.6-1.8 (4H, mid-CH.sub.2 butyl), 2.60 (1H, CH.sub.2 epoxide), 2.79 (1H, CH.sub.2 epoxide), 3.14 (1H, CH epoxide), 3.38 (1H, CH.sub.2 glycidyl ether), 3.53 (2H, CH.sub.2O-glycidyl), 3.65-3.75 (2H, CH.sub.2O-vinyl+1H, CH.sub.2 glycidyl ether), 3.97 (1H, CH.sub.2CH O trans), 4.17 (1H, CH.sub.2CHO cis), 6.47 (1H, CH.sub.2CHO gemi).

Example 4b: Synthesis of 4-Glycidyl Carbonate Butyl Vinyl Ether (GBVE)

[0140] 4-glycidyl carbonate butyl vinyl ether (GCBVE) was synthesized via CO.sub.2 insertion in 17.22 g (0.1 mol) 4-glycidyl butyl vinyl ether in a process as described in the literature (Poly. Chem., 2013, 4, pp. 4545-4561). Yield: 87%. .sup.1H-NMR (CDCl.sub.3, 400 MHz): (ppm)=1.6-1.8 (4H, mid-CH.sub.2 Butyl), 3.55 (2H, CH.sub.2O-glycidyl carbonate), 3.62 (1H, CH.sub.2-carbonate), 3.70 (2H, CH.sub.2O-vinyl+1H, CH.sub.2-carbonate), 3.99 (1H, CH.sub.2CHO trans), 4.19 (1H, CH.sub.2CHO cis), 4.39 (1H, CH.sub.2 carbonate), 4.50 (1H, CH.sub.2 carbonate), 4.82 (1H, CH carbonate), 6.46 (1H, CH.sub.2CHO gemi), 2.5-3.5 (CH.sub.2/CH epoxide). Integration shows <2% remaining epoxy.

Example 5: Polyol Synthesis Through Ring-Opening of GCBVE with Hexamethylenediamine

[0141] 10.81 g (50 mmol) GCBVE and 2.95 g (25 mmol) hexamethylenediamine were readied in a round-bottom flask and heated for 9 h to 80 C. Conversion was observed through disappearance of the carbonate-CO valence vibration bands in the IR spectrum. Yield: quantitative.

Example 6: Synthesis of Vinyl Ether-Functionalized Polyurethanes

[0142] The polyurethanes were synthesized in batches of 15-40 g each. The stoichiometry was calculated such that an NCO-terminated prepolymer was obtained that had a number-average molecular weight of M.sub.n=5000 g/mol. The polyols were dried in a small round-bottom flask in a vacuum at 75 C. The isocyanate compounds were then added at 40 C. A sample of the mixture was removed for IR-spectroscopic investigations. The bands corresponding to NCO valence vibration at approximately 2550 cm.sup.1 was integrated and correlated with the original concentration of the isocyanate groups. The catalyst (50 mg/100 g product, as 50% solution in dry acetone) was then added, and the mixture was carefully heated to 80 C. After one hour of reaction time, an aliquot was removed in order to confirm the desired isocyanate concentration using IR spectroscopy. 90% of the stoichiometric quantity of the end-capping agent was added in order to avoid an excess of hydroxyl groups in the product and, after 30 min, another sample was removed in order to confirm the almost complete conversion of the isocyanate by means of IR spectroscopy. The product was then diluted with dry acetone to 50% polyurethane content. Yield: 95%.

Example 7: Synthesis of a Vinyl Ether-Functionalized Polyurethane

[0143] 10.00 g of the vinyl ether polyol synthesized in example 1 were degassed under reduced pressure at 75 C. At 40 C., 5.82 g isophorone diisocyanate (Merck, 99%) and 0.0162 g Fomrez catalyst UL-28 (Momentive) were then added, and the mixture was heated slowly to 80 C. Side chain vinyl ether-functionalized polyurethane prepolymer (sc-VEPU) was obtained. After 1 h, 0.62 g 4-hydroxybutyl vinyl ether were added, and the reaction mixture was stirred for another 30 minutes in order to also convert the terminal isocyanate groups with HBVE, thereby producing additional terminal vinyl ether groups. The synthesis is shown schematically in FIG. 1. At Mn=5000 g/mol, an average vinyl ether functionality of about 16.5 was obtained.

[0144] For purposes of comparison, a vinyl ether-terminated polyurethane (t-VEPU) and an inactive alkyl-terminated polyurethane (i-PU) was synthesized from IPDI and polypropylene glycol (PPG) (Dow Chemical, Voranol 2000 L, 2000 g/mol) using 1-heptanol or HVBE as end group capping means. For t-VEPU, a vinyl ether functionality of 2 was thus obtained.

[0145] Curing was performed as follows: 1.98 g of the polyurethane functionalized with vinyl ether side chains (sc-VEPU) were mixed with 0.02 g Omnicat 440 (IGM) and 2 g acetone (solvent), with the latter being removed subsequently under reduced pressure. The formulation was applied as a thin film onto a surface and cured under UV irradiation (Omnicure S2000SC, 10 s) in order to yield a tack-free film. The sc-VEPU film applied to a glass surface and cured is shown in FIG. 2b. The figure shows that colorless and highly transparent films can be produced in this way.

Example 8: Synthesis of a Hydrated Vinyl Ether Polyol (Hsc-VEPU)

[0146] A solution of the VEOH from example 1 (0.02 mol/L) in methanol was hydrated using an HC-2.SS H-Cube device for continuous hydration (ThalesNano). The required quantity of hydrogen was produced through electrolysis of water and then dried. The solution of the reactant was then loaded with hydrogen under a pressure of 20 bar at 25 C. in a mixing chamber and fed at a constant flow rate of 1.2 ml/min through the reaction chamber, which contained a 10% Pd/C (CatCart 30) catalyst cartridge. Methanol was removed under reduced pressure. Yield: 98%. .sup.1H-NMR (CDCl.sub.3, 400 MHz): (ppm)=1.2 (6H, CH.sub.3), 1.6-1.8 (12H, mid-CH.sub.2 butyl), 3.4-3.55 (24H, CH.sub.2OCH.sub.2), 3.93 (2H, CHO), 4.19 & 6.46 (residual vinyl ether, peak integration showed 1-2% residue). The synthesis is shown schematically in FIG. 1.

[0147] 4-hydroxybutyl vinyl ether was then added, and the reaction mixture was stirred for another 30 minutes in order to convert the terminal isocyanate groups with HBVE, thereby producing terminal vinyl ether groups. For hsc-VEPU, a vinyl ether functionality of 2 was thus obtained.

Example 9: UV-NIR Rheometry

[0148] The simultaneous measurement of the viscoelastic characteristics and the absorption of near-infrared (NIR) spectra after UV initiation was carried out using a rheometer and an experimental setup as described by Scherzer (Scherzer, T.; SchrOder, M. W. Proc. RadTech Europe 2009 Conference 2009). An Anton Paar MCR 302 rheometer was used in conjunction with a Bruker MPA FT-NIR spectrometer and an Omnicure S 2000 SC light source, with both being triggered by the Rheometer software. The experimental setup is shown schematically in FIG. 2a. The sample was placed in the center of the quartz base plate, and an aluminum plate having a 20 mm diameter was used as a movable spindle with an initial gap of 0.3 mm. A normal force of zero was used for the automatic gap control during shrinking of the sample in order to prevent delamination. The mechanical data were obtained via oscillation of the spindle. An ascending measurement profile was used in order ensure linear viscoelastic behavior and to remain within the limits of the instrument, since the sample moduli increase by several orders of magnitude during curing. Before UV irradiation, a sinusoidal tensile stress of 10% was applied for 30 s at a frequency of 10 Hz. During UV irradiation, which was performed through the transparent base plate, the tensile stress was reduced linearly within 10 seconds from 10% to 0.1% and mechanical data were recorded at a rate of 1 s.sup.1 (no ascending measurement profile was applied to the inactive heptanol-capped polyurethane). The UV light source was set such that it irradiated the sample for 10 seconds. The intensity of 2 mW cm.sup.2 UVC (189 mW cm.sup.2 UVA-C) on the surface of the quartz plate was checked regularly using a spectral radiometer (OpSyTec Dr. Gbel). After UV irradiation, the post-curing development was recorded for 200 s under a tensile stress of 0.1%. Several samples were then irradiated for an additional 10 s and the post-curing was recorded again. No attempt was made to removed dissolved gases from the samples, and the measurements were recorded under instrumental air atmosphere (H.sub.2O: 1.1 mg/m.sup.3). For purposes of comparison, an experiment was conducted under nitrogen atmosphere (N.sub.2: <99.9996%, O.sub.2: <0.5 ppm, H.sub.2O: <1 ppm). The NIR spectra were recorded at a resolution of 16 cm.sup.1 at a constant recording rate of about 2 spectra s.sup.1. The relative vinyl ether concentration was calculated from the integrated peak area of the CC stretching vibration at approximately 6200 cm.sup.1. The mean value for this peak in the spectra before irradiation was set at 100%.

[0149] FIG. 2c shows the rheometric plots for the synthesized polyurethanes i-PU, t-VEPU, sc-VEPU, and hsc-VEPU (see examples 6-8). The irradiation period of 10 seconds is designated by the region in the diagram that is shaded in gray. As expected, i-PU did not exhibit any increase in the storage modulus. The slight decrease in the storage modulus upon irradiation of all of the samples is likely a thermal effect due to light absorption or the breaking-down of the photoinitiator, it being possible for cleaved-off initiator fragments to act as softeners. The t-VEPU exhibits a delay of about 10 s between irradiation and the initial quick increase in the storage modulus. In the case of the curing of the terminally functionalized PUs under dry nitrogen in order to rule out any influence of oxygen or air humidity, no improvement was observed. The delay can likely be attributed to a relatively slow initial reaction, and a similar behavior was observed for the side chain-functionalized samples. Due to its chemical structure, the t-VEPU has a relatively low initial storage modulus, since it has a small quantity of urethane bonds and approximately 82 wt % PPG segments. The storage modulus can therefore increase by several orders of magnitude during UV irradiation, but it does not exceed the Dahlquist criterion, which indicates the limit value over which tack-free films are obtained (Dahlquist, C. A., Tack. In Adhesion Fundamentals and Practice, 1969; pp. 143-151). The stickiness of the cured t-VEPU shows that the flexible polymer chains cannot be crosslinked strongly enough via the terminal, reactive groups. The first harmonic of the stretch vibration of the vinyl ether CC double bond can be found in the NIR spectrum as a relatively sharp absorption band at 6200 cm.sup.1. (Workman, J.; Weyer, L., Alkenes and Alkynes. In Practical Guide and Spectral Atlas for Interpretive Near-Infrared Spectroscopy, Second Edition, CRC Press: 2012; pp 33-38.; Scherzer, T.; Buchmeiser, M. R. Macromolecular Chemistry and Physics 2007, 208, (9), 946-954). The analysis of the integrated peak area shows the consumption of the vinyl ether. Due to the low concentration of end groups, however, the signal/background ratio was too low in order to reliably calculate the conversion.

[0150] The hsc-VEPU, which also bears only terminal vinyl ether groups, was prepared in order to study the influence of the polyurethane backbone. The short polyol structure of the hydrated VEOH shifts the composition in the direction of a higher content of hard urethane segments, which leads to stronger intermolecular interactions and higher initial viscosity. Accordingly, the storage modulus is significantly higher at the beginning and develops at a lower rate after UV initiation. This can be attributed to reduced mobility on the part of the functional groups and slower diffusion kinetics. Macromonomers in particular are strongly influenced by increased viscosities. On the other hand, the slower reaction clearly shows the post-curing. Even though the cured hsc-VEPU exhibits a greater storage modulus than t-VEPU, it is still slightly tacky.

[0151] By contrast, the high-quality vinyl ether-functionalized sc-VEPU cures with a comparable backbone structure to a tack-free film and, as a direct consequence of the high crosslinking rates that can be achieved, exhibits an outstanding storage modulus, which is important particularly for its suitability as a building material.

[0152] FIG. 3 shows the curing of side chain-functionalized polyurethane (sc-VEPU) over the development of the storage moduli and relative vinyl ether contents by means of in-situ NIR measurement at different temperatures (25 C., 40 C., and 60 C.), with the measurement being accelerated at higher temperatures. At 25 C. and 40 C. conversion rates of approximately 45% and 75% are achieved after a first initiation. A second initiation can increase the conversion to approximately 70% and 90%. It is assumed that the active chain ends in crosslinked regions are enclosed and therefore become inaccessible for residual vinyl ether groups. The second initiation produces new polymerizable groups that are then less crosslinked and more mobile at this point in time. One noteworthy and mechanistically important observation is that, at 60 C., the sc-VEOH polymerization takes place very quickly to nearly complete conversion. A strong influence from the termination can therefore be ruled out, since the corresponding termination reactions have higher activation energies than the ongoing reaction and are thus accelerated more strongly at elevated temperatures.

[0153] Slightly negative values for the residual vinyl ether concentration in FIG. 3 result from the complete disappearance of the peak in a convex region of the spectra (see FIG. 4). FIG. 4 shows the NIR spectra of the sc-VEPU (example 7) with UV-initiated curing at 60 C. The NIR spectra were recorded using the previously described UV-NIR rheometer setup, and the sample was irradiated for 30-40 s. The increasing overall intensity at this point in time correlates with the shrinking of the sample by 3.7%. The peak at 6200 cm.sup.1 is correlated with the first harmonic of the CH axial vibration and decreases during polymerization after UV initiation.

[0154] The results of the measurements are shown in FIGS. 5-8. FIG. 5 shows the IR spectrum for i-PU synthesis (inactive alkyl-terminated polyurethane). This polyurethane was synthesized starting from isophorone diisocyanate (IPDI) and polypropylene glycol (PPG) as specified in example 6 and terminated with 1-heptanol (FIG. 1). Spectra were recorded after the addition of the isocyanate (reactant), after one hour of reaction time (prepolymer), and after 30 min after the addition of the terminating agent (terminated). Several structurally relevant peaks are correlated. The integrated peak areas that correspond to the NCO valence vibration at 2550 cm.sup.1, as well as the associated molar quantities that were calculated from the stoichiometry, are as follows:

TABLE-US-00001 n(NCO) A(NCO) [mmol] % [Counts] % Reactant 45.0 100 9567 100 Prepolymer 14.3 32 3005 31 Terminated 1.4 3 276 3

[0155] FIG. 6 shows the IR spectrum of the t-VEPU synthesis (vinyl ether-terminated polyurethane). The polyurethane was synthesized starting from IPDI and PPG as specified in example 6 and terminated with 4-hydroxybutyl vinyl ether (FIG. 1). Spectra were recorded after the addition of the isocyanate (reactant), after one hour of reaction time (prepolymer), and after 30 min after the addition of the terminating agent (terminated). Several structurally relevant peaks are correlated. The integrated peak areas that correspond to the NCO valence vibration at 2550 cm.sup.1, as well as the associated molar quantities that were calculated from the stoichiometry, are as follows:

TABLE-US-00002 n(NCO) A(NCO) [mmol] % [Counts] % Reactant 45.0 100 9839 100 Prepolymer 14.3 32 3022 31 Terminated 1.4 3 358 4

[0156] FIG. 7 shows the IR spectrum of the sc-VEPU synthesis (side chain vinyl ether-functionalized polyurethane). The polyurethane was synthesized starting from IPDI and VEOH as specified in example 7 and terminated with 4-hydroxybutyl vinyl ether (FIG. 1). Spectra were recorded after the addition of the isocyanate (reactant), after one hour of reaction time (prepolymer), and after 30 min after the addition of the terminating agent (terminated). Several structurally relevant peaks are correlated. The CC axial vibration band of the vinyl ether at 1615 cm.sup.1 clearly shows a relatively high vinyl ether concentration and confirms that no consumption of the vinyl ether occurs under synthesis conditions. The integrated peak areas that correspond to the NCO valence vibration at 2550 cm.sup.1, as well as the associated molar quantities that were calculated from the stoichiometry, are as follows:

TABLE-US-00003 n(NCO) A(NCO) [mmol] % [Counts] % Reactant 52.4 100 26020 100 Prepolymer 6.3 12 4600 18 Terminated 0.6 1 294 1

[0157] It can be seen that the reaction can be controlled well under the given conditions.

[0158] FIG. 8 shows the IR spectrum of the hsc-VEPU synthesis (hydrated side chain vinyl ether-functionalized polyurethane). The polyurethane was synthesized starting from IPDI and VEOH as specified in example 7 and terminated with 4-hydroxybutyl vinyl ether. It was then hydrated (FIG. 1). Spectra were recorded after the addition of the isocyanate (reactant), after one hour of reaction time (prepolymer), and after 30 min after the addition of the terminating agent (terminated). Several structurally relevant peaks are correlated. The CC axial vibration band of the vinyl ether at 1615 cm.sup.1 shows that the hsc-VEPU has only slight traces of residual vinyl ether groups. The integrated peak areas that correspond to the NCO valence vibration at 2550 cm.sup.1, as well as the associated molar quantities that were calculated from the stoichiometry, are as follows:

TABLE-US-00004 n(NCO) A(NCO) [mmol] % [Counts] % Reactant 52.4 100 25601 100 Prepolymer 6.3 12 3277 13 Terminated 0.6 1 201 1

BRIEF DESCRIPTION OF THE DRAWINGS

[0159] FIG. 1 schematically illustrates one scheme for synthesizing vinyl ether-functionalized polyurethanes (VEPUs).

[0160] FIG. 2A schematically illustrates a setup to simultaneously measure the viscoelastic characteristics and the absorption of near-infrared (NIR) spectra after UV initiation of a composition.

[0161] FIG. 2B shows a sc-VEPU film applied to a glass surface and cured to produce a colorless and highly transparent film.

[0162] FIG. 2C shows rheometric plots for the synthesized polyurethanes i-PU, t-VEPU, sc-VEPU, and hsc-VEPU.

[0163] FIG. 3 shows the curing of side chain-functionalized polyurethane (sc-VEPU) over the development of the storage moduli and relative vinyl ether contents by means of in-situ NIR measurement at different temperatures (25 C., 40 C., and 60 C.).

[0164] FIG. 4 shows the NIR spectra of the sc-VEPU (example 7) with UV-initiated curing at 60 C.

[0165] FIG. 5 shows the IR spectrum for i-PU synthesis (inactive alkyl-terminated polyurethane).

[0166] FIG. 6 shows the IR spectrum of the t-VEPU synthesis (vinyl ether-terminated polyurethane).

[0167] FIG. 7 shows the IR spectrum of the sc-VEPU synthesis (side chain vinyl ether-functionalized polyurethane).

[0168] FIG. 8 shows the IR spectrum of the hsc-VEPU synthesis (hydrated side chain vinyl ether-functionalized polyurethane).