METHOD FOR COMPLETE RECYCLING OF INORGANIC-FIBER REINFORCED EPOXY COMPOSITES WITH BORON HALIDES

Abstract

The present invention is related to a method for recycling a composite material comprising inorganic fibers and an epoxy-resin in a one pot reaction, wherein the method comprises reacting the composite material with a boron halide in a solvent.

Claims

1. Method for recycling a composite material comprising inorganic fibers and/or organic fibers and an epoxy-resin in a one pot reaction, wherein the method comprises reacting the composite material with a boron halide in a solvent.

2. Method according to claim 1, wherein the inorganic fibers are glass fibers and/or carbon fibers.

3. Method according to claim 1, wherein the epoxy-resin comprises an alkyl aryl ether resin moiety.

4. Method according to claim 1, wherein the epoxy-resin comprises bisphenol-based monomer units and polyol-based monomer units.

5. Method according to claim 4, wherein the bisphenol-based monomer units are brominated.

6. Method according to claim 1, wherein the boron halide is a boron trihalide, an organylboron dihalide, an organyloxyboron, dihalide or mixtures of two or more thereof.

7. Method according to claim 1, wherein the solvent is a hydrocarbon, a halogenated hydrocarbon, or a mixture of two or more thereof.

8. Method according to claim 1, wherein the reacting is performed at a temperature from 0 to 150° C.

9. Method according to claim 4 wherein the bisphenol-based monomer units comprise non-brominated bisphenol-based monomer units and brominated bisphenol-based monomer units and the method comprises a further step of crystallizing to separate the non-brominated bisphenol-based monomer units and the brominated bisphenol-based monomer units from each other.

10. Method according to claim 1 further comprising a step, after the reacting of using one or more of the products achieved by the reacting of the composite material comprising inorganic fibers and an epoxy-resin with the boron halide.

Description

[0025] In the following, the invention will be described referring to specific examples and the Figures wherein

[0026] FIG. 1 from sample 5 shows six pieces of composite DE104 ((a), each ca. 18×10×1.5 mm, total weight 3.02 g), glass fiber pieces (b) obtained from DE104 after treatment with 30 mL of a 1M solution of BCl.sub.3 (3.52 g, 30.00 mmol) in DCM for 24 h at room temperature, then 64 h at 50-55° C. and the four separate fractions VZ-DE-1-1 to VZ-DE-1-4 (c) weighing 370 mg (1,3-dichloropropan-2-ol and a mixture of bisphenol derivatives), 280 mg (BPA, TBBA and small impurities of 1,3-dichloropropan-2-ol), 40 mg (oligomers and polymers) and 270 mg (oligomers and polymers), respectively.

[0027] FIG. 2 from sample 9 shows carbon fiber reinforced epoxy composite from a wind turbine ((a), 18×9×1.5 mm, 493 mg), a part of carbon fiber obtained from it after treatment with 1M solution of BCl.sub.3 in dry DCM at 60-65° C. for 70 h (b) and partly product VZ-CFK-V3 (mixture of BPA and polymer) (c).

TABLE-US-00001 FIG. 3 [00005] Current Data Parameters NAME vz2628-1 EXPNO 10 PROCNO 1 F2 - Acquisition Parameters Date_ 20160223 Time 18.57 INSTRUM spect .sup.1H-NMR (400 MHz, CDCl.sub.3) PROBHD 5 mm PABBO BB- Shift ppm 1.66 (d, J = 126.66 Hz) PULPROG zg30 Shift ppm 3.80 (d, J = 143.50 Hz) TD 65536 Shift ppm 6.82 (d, J = 8.84 Hz) SOLVENT CDCl3 Shift ppm 7.17 (d, J = 8.84 Hz) NS 16 FIG. 4 [00006] Current Data Parameters NAME vz2628-1 EXPNO 11 PROCNO 1 F2 - Acquisition Parameters Date_ 20160223 Time 19.27 INSTRUM spect PROBHD 5 mm PABBO BB- .sup.13C-NMR in CDCl.sub.3, 100 MHz PULPROG zgpg30 TD 65536 SOLVENT CDCl3 NS 512 FIG. 5 [00007] .sup.1H-NMR (400 MHz, DMSO-d.sub.6) Current Data Parameters Shift ppm 1.52 (d, J = 126.42 Hz) NAME vz-BPA Shift ppm 6.63 (d, J = 8.70 Hz) EXPNO 10 Shift ppm 6.97 (d, J = 8.70 Hz) PROCNO 1 VZ-BPA F2 - Acquisition Parameters Date_ 20160321 Time 14.46 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT DMSO NS 16 FIG. 6 [00008] VZ-BPA Current Data Parameters .sup.13C-NMR in DMSO-d.sub.6, 100 MHz NAME vz-BPA EXPNO 11 PROCNO 1 F2 - Acquisition Parameters Date_ 20160321 Time 15.17 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zgpg30 TD 65536 SOLVENT DMSO NS 512 FIG. 7 [00009] Current Data Parameters NAME vz2565 EXPNO 10 PROCNO 1 F2 - Acquisition Parameters Date_ 20150831 Time 17.02 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 .sup.1H-NMR (400 MHz, CDCl.sub.3) TD 65536 Shift ppm 1.48 (t, J = 7.00 Hz) SOLVENT CDCl3 Shift ppm 4.08 (q, J = 7.00 Hz) NS 16 Shift ppm 7.29 (dd, J = 2.26, 164.17 Hz) FIG. 8 [00010] Current Data Parameters NAME vz2565 EXPNO 11 PROCNO 1 F2 - Acquisition Parameters Date_ 20150831 Time 17.32 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zgpg30 .sup.13C-NMR in CDCl.sub.3, 100 MHz TD 65536 SOLVENT CDCl3 NS 512 FIG. 9 [00011] Current Data Parameters NAME vz-G10-4-1 EXPNO 10 PROCNO 1 F2 - Acquisition Parameters Date_ 20160920 Time 15.47 .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) of INSTRUM spect VZ-G10-4-1 (a mixture of BPA, phenol and PROBHD 5 mm PABBO BB- 1,3-dichloropropan-2-ol (relation 100:0.50:1.12, PULPROG zg30 respectively) from cleavage of G10 with TD 65536 BCl.sub.3) SOLVENT DMSO NS 64 FIG. 10 [00012] Current Data Parameters NAME vz-G10-4-1 EXPNO 11 PROCNO 1 F2 - Acquisition Parameters Date_ 20160920 Time 16.10 .sup.13C-NMR spectrum (100 MHz, DMSO-d.sub.6) of INSTRUM spect VZ-G10-4-1 (a mixture of BPA, phenol and 1,3- PROBHD 5 mm PABBO BB- dichloropropan-2-ol (relation 100:0.50:1.12, PULPROG zgpg30 respectively) from cleavage of G10 with BCl.sub.3) TD 65536 SOLVENT DMSO NS 512 FIG. 11 .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) Current Data Parameters of VZ-G10-4-2 (a mixture of oligomers NAME vz-G10-4-2 with small amounts of BPA and phenol EXPNO 10 from cleavage of G10 with BCl.sub.3) PROCNO 1 F2 - Acquisition Parameters Date_ 20160921 Time 15.43 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT DMSO NS 64 FIG. 12 .sup.1H-NMR spectrum (400 MHz, CDCl.sub.3) of Current Data Parameters VZ-DE-1-1 (1,3-dichloropropan-2-ol and NAME vz-DE-1-1 a mixture of bisphenol derivatives - first EXPNO 10 fraction after treatment of DE104 with PROCNO 1 BCl.sub.3) F2 - Acquisition Parameters Date_ 20160817 Time 15.55 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT CDCl3 NS 16 FIG. 13 [00013] .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-DE-1-2 (BPA, TBBA and small NAME vz-DE-1-2 impurities of 1,3-dichloropropan-2-ol- EXPNO 10 second fraction after treatment of DE104 PROCNO 1 with BCl.sub.3) F2 - Acquisition Parameters Date_ 20160818 Time 15.48 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT DMSO NS 64 FIG. 14 .sup.1H-NMR spectrum (400 MHz, CDCl.sub.3) of Current Data Parameters VZ-DE-1-3 (oligomers and polymers - third NAME vz-DE-1-3 fraction after treatment of DE104 with BCl.sub.3) EXPNO 10 PROCNO 1 F2 - Acquisition Parameters Date_ 20160817 Time 15.42 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT CDCl3 NS 64 FIG. 15 .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-DE-1-4 (oligomers and polymers - fourth NAME vz-DE-1-4 fraction after treatment of DE104 with BCl.sub.3) EXPNO 10 PROCNO 1 F2 - Acquisition Parameters Date_ 20160818 Time 15.36 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT DMSO NS 64 FIG. 16 [00014] .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-MPM-C3 (a mixture of BPA, TBBA and NAME vz-MPM-C3 1,3-dichloropropan-2-ol (relation 1:0.5:2, EXPNO 10 respectively) from cleavage of recyclate MPM PROCNO 1 with BCl.sub.3) F2 - Acquisition Parameters Date_ 20160517 Time 15.31 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 66536 SOLVENT DMSO NS 16 FIG. 17 [00015] .sup.13C-NMR spectrum (100 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-MPM-C3 (a mixture of BPA, TBBA and NAME vz-MPM-C3 1,3-dichloropropan-2-ol (relation 1:0.5:2, EXPNO 11 respectively) from cleavage of recyclate MPM PROCNO 1 with BCl.sub.3) F2 - Acquisition Parameters Date_ 20160517 Time 16.01 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zgpg30 TD 65536 SOLVENT DMSO NS 512 FIG. 18 [00016] .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-MPM-BBr-2 (a mixture of BPA, TBBA NAME vz-MPM-BBr-2 and 1,2,3-tribromopropane (relation 1:0.44:1.88, EXPNO 10 respectively) after treatment of PROCNO 1 recyclate MPM with BBr.sub.3) F2 - Acquisition Parameters Date_ 20160502 Time 12.43 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT DMSO NS 16 FIG. 19 [00017] .sup.13C-NMR spectrum (100 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-MPM-BBr-2 (a mixture of BPA, TBBA and NAME vz-MPM-BBr-2 1,2,3-tribromopropane (relation 1:0.44:1.88, EXPNO 11 respectively) after treatment of recyclate MPM PROCNO 1 with BBr.sub.3) F2 - Acquisition Parameters Date_ 20160502 Time 12.57 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zgpg30 TD 65536 SOLVENT DMSO NS 512 FIG. 20 [00018] .sup.13C-DEPT-NMR spectrum (100 MHz, DMSO- Current Data Parameters d.sub.6) of VZ-MPM-BBr-2 (a mixture of BPA, NAME vz-MPM-BBr-2 TBBA and 1,2,3-tribromopropane (relation EXPNO 12 1:0.44:1.88, respectively) after treatment of PROCNO 1 recyclate MPM with BBr.sub.3) F2 - Acquisition Parameters Date_ 20160502 Time 13.40 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG dept135 TD 65536 SOLVENT DMSO NS 512 FIG. 21 [00019] Current Data Parameters NAME vz-cfk-1 EXPNO 10 PROCNO 1 F2 - Acquisition Parameters Date_ 20160728 Time 15.42 .sup.1H-NMR spectrum (400 MHz, CDCl.sub.3) of INSTRUM spect VZ-CFK-1 (a mixture of BPA, 1,2-dibromo- PROBHD 5 mm PABBO BB- propan-2-ol and small impurities of PULPROG zg30 undefined compounds after cleavage of CRP TD 65536 with BBr.sub.3) SOLVENT CDCl3 .sup.1H NMR (400 MHz, CDCl.sub.3) NS 64 Shift ppm 6.73 (d, J = 8.72 Hz) Shift ppm 7.09 (d, J = 8.72 Hz) FIG. 22 [00020] Current Data Parameters NAME vz-CFK-1 EXPNO 11 PROCNO 1 F2 - Acquisition Parame Date_ 20180202 Time 9.28 .sup.13C-NMR spectrum (100 MHz, DMSO-d.sub.6) of INSTRUM spect VZ-CFK-1 (a mixture of BPA, 1,2-dibromo- PROBHD 5 mm PABBO BB- propan-2-ol and small impurities of PULPROG zgpg30 undefined compounds after cleavage of CRP TD 65536 with BBr.sub.3) SOLVENT DMSO NS 512 FIG. 23 [00021] Current Data Parameters NAME vz-CFK-1 EXPNO 12 PROCNO 1 F2 - Acquisition Parameter: Date_ 20180202 Time 9.54 .sup.13C-DEPT-NMR spectrum (100 MHz, INSTRUM spect DMSO-d.sub.6) of VZ-CFK-1 (a mixture of BPA, PROBHD 5 mm PABBO BB- 1,2-dibromopropan-2-ol and small PULPROG dept135 impurities of undefined compounds after TD 65536 cleavage of CRP with BBr.sub.3) SOLVENT DMSO NS 512 FIG. 24 .sup.1H-NMR spectrum (400 MHz, DMSO-d.sub.6) of Current Data Parameters VZ-CFK-V3 (a mixture of BPA and polymer NAME VZ-CFK-V3 after treatment of CRP with BCl.sub.3) EXPNO 10 .sup.1H NMR (400 MHz, DMSO-d.sub.6) PROCNO 1 Shift ppm 6.63 (d, J = 8.70 Hz) F2 - Acquisition Parameters Shift ppm 6.97 (d, J = 8.70 Hz) Date_ 20180130 Time 19.42 INSTRUM spect PROBHD 5 mm PABBO BB- PULPROG zg30 TD 65536 SOLVENT DMSO

EXAMPLES

[0028] 1) Synthesis of BPA Dimethyl Ether and Cleavage of the Ether Bond with Boron Tribromide.

##STR00022## [0029] a) Synthesis of BPA dimethyl ether. To a mixture of BPA (2.28 g, 10.00 mmol) and potassium carbonate (3.48 g, 25.00 mmol) in 25 mL of DMF methyl iodide (3.55 g, 25.00 mmol) was added within to min at 0° C. The reaction mixture was then stirred at room temperature for 24 h, poured into 200 mL of cold water, treated with 5 mL conc. HCl under stirring and extracted with DCM (4×50 mL). The organic layer was washed with water (2×too mL), dried with calcium chloride and concentrated under reduced pressure. After treatment with to mL hexane the precipitate was filtered with suction, washed with 5 mL hexane and dried under reduced pressure. BPA dimethyl ether was obtained as a white solid (yield 2.38 g, 93%).

[0030] Characterization was by .sup.1H-NMR (FIG. 3) and .sup.13C-NMR (FIG. 4). [0031] b) Cleavage of the ether bond in BPA dimethyl ether with boron tribromide. To a solution of 0.095 mL (250 mg, 1.00 mmol) BBr.sub.3 in to mL of dry DCM 256 mg (Loo mmol) of BPA dimethyl ether were added under stirring at room temperature. After 2 h, the reaction mixture was poured into too mL of ice water and extracted with DCM (4×20 mL). The organic layer was washed with water (2×50 mL), dried with calcium chloride and concentrated under reduced pressure. After treatment with 3 mL hexane the precipitate was filtered with suction, washed with 1 mL of hexane and dried under reduced pressure. BPA was obtained as a white solid (yield 215 mg, 94%).

[0032] Characterization was by .sup.1H-NMR (FIG. 5) and .sup.13C-NMR (FIG. 6).

[0033] 2) Synthesis of TBBA diethyl ether and cleavage of the ether bond with boron tribromide.

##STR00023##

[0034] TBBA diethyl ether was obtained similarly to BPA dimethyl ether from TBBA (544 mg, 1.00 mmol) and ethyl bromide (2.50 eq). White solid, yield 570 mg, 95%.

[0035] Characterization was by .sup.1H-NMR (FIG. 7) and .sup.13C-NMR (FIG. 8).

[0036] Cleavage of the ether bond in TBBA diethyl ether (300 mg, 0.50 mmol) with boron tribromide was carried out similarly to the synthesis of BPA from BPA dimethyl ether. White solid, yield 253 mg, 93%.

[0037] Characterization was by .sup.1H-NMR and .sup.13C-NMR.

[0038] 3) Recycling of bromine-free glass fiber reinforced epoxy composite Gin with BCl.sub.3.

[0039] To a suspension of 3.00 g G10 powder (ca. 1.20 g polymer, content 40% in composite G10) in 10 mL of dry DCM in a 100 mL glass pressure vessel 10 mL of a 1M solution of BCl.sub.3 (1.17 g, 10.00 mmol) in dry DCM were added; the reaction mixture was stirred for 24 h at room temperature, then 68 h at 55−60° C. After cooling to room temperature, the reaction mixture was poured into 200 mL of ice water and extracted with DCM (5×50 mL). The organic layer was dried with calcium chloride. Removal of the solvent in vacuum afforded 775 mg VZ-G10-4-1 as a dark viscous oil. According to the .sup.1H-NMR spectra the product VZ-G10-4-1 was a mixture of 297 mg BPA, 148 mg phenol and 330 mg 1,3-dichloropropan-2-ol (relation 1.00:0.50:1.12, respectively). The residue was washed (3×30 mL) with a mixture of acetone/methanol 1:1, then with ethyl acetate (5×50 mL). After removal of the solvents from the combined organic layers under reduced pressure, 30 mL of diethyl ether were added to the residue under stirring. The precipitate was filtered off with suction, washed with 5 mL of diethyl ether and dried under reduced pressure. The product VZ-G10-4-2 (220 mg) was obtained as a brown solid. According to the .sup.1H-NMR spectra (FIG. 11) the product VZ-G10-4-2 was a mixture of oligomers with small amounts of BPA and phenol. Conversion of the organic part of the starting material was 83% (775+220=995/1200). The amount of the glass fiber after washing with methanol, water, acetone and drying in vacuum was 1920 mg.

[0040] Characterization was by .sup.1H-NMR (FIG. 9) and .sup.13C-NMR (FIG. 10).

[0041] 4) Treatment of BPA with boron trichloride.

[0042] In sample 3 and in some other experiments we observed the formation of phenol. It was important to detect, whether phenol was formed by retro Friedel-Crafts reaction of BPA or whether it arises directly from the epoxy resin upon treatment with BCl.sub.3.

[0043] To a suspension of 1.00 g BPA (4.38 mmol) in 10 mL of dry DCM in a 100 mL glass pressure vessel 30 mL of a 1M solution of BCl.sub.3 (3.52 g, 30.00 mmol) in dry DCM were added. The reaction mixture was stirred for 24 h at room temperature, then for 40 h at 55−60° C. After cooling to room temperature a TLC test (petrol ether/ethyl acetate 2:1) showed unreacted BPA, only, no formation of phenol was observed. This confirmed that phenol was formed directly from the epoxy resin.

##STR00024##

[0044] 5) Recycling of DE104 (glass fiber reinforced epoxy composite with flame-retardant tetrabromobisphenol A) with BCl.sub.3.

[0045] To six pieces of composite DE104 (each ca. 18×10×1.5 mm, total weight 3.02 g, ca. 1.20 g polymer, content 40% in composite DE104) in 10 mL of dry DCM in a 100 mL glass pressure vessel 10 mL of a 1M solution of BCl.sub.3 (1.17 g, 10.00 mmol) in dry DCM were added. The reaction mixture was stirred for 24 h at room temperature, then for 64 h at 50−55° C. Work-up was carried out similarly to sample 3 with an additional column chromatography using a mixture of petrol ether/ethyl acetate 10:1 for the fractions 1-3, then pure acetone for fraction 4. After evaporation of the solvent in vacuum the four separate fractions VZ-DE-1-1 to VZ-DE-1-4 weighing 370 mg (VZ-DE-1-1, 1,3-dichloropropan-2-ol and a mixture of bisphenol derivatives), 280 mg (VZ-DE-1-2, BPA, TBBA and small impurities of 1,3-dichloropropan-2-ol), 40 mg VZ-DE-1-3 (oligomers and polymers), and 270 mg (VZ-DE-1-4, oligomers and polymers), respectively, were obtained. The structures of the compounds obtained were identical with the original .sup.1H- and .sup.13C-NMR spectra. The conversion rate of the organic part of the starting material (FIGS. 12 to 15) was 80% (370+280+40+270=960/1200). The amount of the glass fiber after washing with methanol, water, acetone and drying in vacuum was 1670 mg.

[0046] 6) Recycling of recyclate MPM (glass fiber reinforced epoxy composite with flame-retardant tetrabromobisphenol A from circuit boards) with BCl.sub.3.

[0047] To a suspension of 1.50 g recyclate MPM powder in 5 mL of dry DCM in a 100 mL glass pressure vessel were added 10.7 mL of a 1M solution of BCl.sub.3 (1.25 g, 10.70 mmol) in dry DCM. The reaction mixture was stirred for 24 h at room temperature, then for 70 h at 55-60° C. Work-up was carried out similarly to sample 3. After evaporation of the solvent in vacuum 580 mg of product VZ-MPM-C3 were obtained as a dark viscous oil. According to the .sup.1H- and .sup.13C-MR spectra product VZ-MPM-C3 (FIGS. 16 and 17) was a mixture of BPA, TBBA and 1,3-dichloropropan-2-ol (relation 1:0.5:2, respectively). Small amounts of phenol and high molecular compounds were present, too. The weight of the glass fiber after washing with methanol, water, acetone and drying in vacuum was 670 mg.

[0048] 7) Recycling of recyclate MPM (glass fiber reinforced epoxy composite with flame-retardant tetrabromobisphenol from circuit boards) with BBr.sub.3.

[0049] To a suspension of 1.50 g recyclate MPM powder in 20 mL of dry DCM in a 100 mL glass pressure vessel 1.02 mL (2.68 g, 10.70 mmol) of BBr.sub.3 were added, and the reaction mixture was stirred for 1 d at room temperature, then at 50-55° C. for 1 h. After cooling to room temperature the reaction mixture was poured into 200 mL of ice water and extracted with ethyl acetate (3×50 mL). The organic layer was dried with sodium sulfate. Solvent removal in vacuum afforded 590 mg of product VZ-MPM-BBr-2 as a dark viscous oil. According to the .sup.1H- and .sup.13C-NMR spectra product VZ-MPM-BBr-2 (FIGS. 18 to 20) was a mixture of BPA, TBBA and 1,2,3-tribromopropane (relation 1: 0.44:1.88, respectively). The weight of the glass fiber after washing with methanol, water, acetone and drying in vacuum was 640 mg.

[0050] 8) Recycling of a carbon fiber reinforced epoxy composite (CRP from a wind turbine with 70% content of carbon fiber) with BBr.sub.3.

[0051] To a piece of a CRP (0.730 g, 20×10×2 mm) in a 25 mL round bottom glass Schlenk flask to mL of dry DCM and 0.25 mL (0.67 g, 2.67 mmol) BBr.sub.3 were added. The reaction mixture was stirred under nitrogen for 4 d at room temperature. After cooling to −10° C., the reaction mixture was poured into too mL of ice water and extracted with ethyl acetate (3×50 mL). The organic layer was dried with sodium sulfate. Removal of the solvent in vacuum afforded 180 mg of product VZ-CFK-1 as a dark viscous oil. According to the .sup.1H- and .sup.13C-NMR spectra (FIGS. 21 to 23) product VZ-CFK-1 was a mixture of BPA, 1,3-dibromopropan-2-ol and small impurities of undefined compounds. The weight of the carbon fiber after washing with methanol, water, acetone and drying in vacuum was 511 mg.

[0052] 9) Recycling of a carbon fiber reinforced epoxy composite (CRP from a wind turbine with 70% content of carbon fiber) with BCl.sub.3.

[0053] To four pieces of a CRP (each ca. 25×2×2 mm, total weight 0.800 g) in a too mL glass pressure vessel 10.7 mL of a 1M solution of BCl.sub.3 (1.25 g, 10.70 mmol) in dry DCM were added. The reaction mixture was stirred for 24 h at room temperature, then for 70 h at 60−65° C. After cooling to −10° C., the reaction mixture was poured into 200 mL of ice water and extracted with ethyl acetate (3×50 mL). The organic layer was dried with sodium sulfate. Solvent removal in vacuum afforded 190 mg of product VZ-CFK-V3 as a dark solid. According to the .sup.1H-NMR spectrum (FIG. 24) product VZ-CFK-V3 was a mixture of BPA and polymer. The weight of the carbon fiber after washing with methanol, water, acetone and drying in vacuum was 515 mg.

REFERENCES

[0054] [1] M. Motavalli; C. Czaderski; A. Schumacher; D. Gsell. Textiles, Polymers and Composites for Buildings. 4—Fibre Reinforced Polymer Composite Materials for Building and Construction. Woodhead Publishing Series in Textiles, 2010, 69-128. [0055] [2] C. E. Bakis; Lawrence C. Bank; V. L. Brown, M.; E. Cosenza; J. F. Davalos; J. J. Lesko; A. Machida; S. H. Rizkalla; and T. C. Triantafillou. Fiber-Reinforced Polymer Composites for Construction, J. Composites for Construction, 2002, 6(2), doi.org/10.1061/(ASCE)1090-0268(2002)6:2(73). [0056] [3] Liang, B.; Qin, B.; Pastine, S.; Li, X. Reinforced Composite and Method for Recycling the Same, US 20140221510 A1, 2014. [0057] [4] Adam, G. A. Recycling Carbon Fibers from Epoxy Using Solvent Cracking. U.S. Pat. No. 8,920,932, 2014. [0058] [5] Asmatulu, E.; Twomey, J.; Overcash, M. Recycling of Fiber-Reinforced Composites and Direct Structural Composite Recycling Concept. J. Composite Materials, 2014, 48 (5), 593-608. [0059] [6] Taynton P.; Ni H.; Zhu C.; Loob S.; Jin Y.; Zhang W.; Qi H. J. Repairable Woven Carbon Fiber Composites with Full Recyclability Enabled by Malleable Polyimine Networks. Advanced materials (Deerfield Beach, Fla.), 2016, 28(15), 2904-9. [0060] [7] Kaneko, M.; Usami, K.; Ishimoto, T. Prepregs and Fiber-Reinforced Composites Therefrom. Jpn. Kokai Tokkyo Koho, 2010, JP 2010241845. [0061] [8] Y. Wang, X. Cui, H. Ge, Y. Yang, Y. Wang, C. Zhang, J. Li, T. Deng, Z. Qin, X. Hou. Chemical Recycling of Carbon Fiber Reinforced Epoxy Resin Composites via Selective Cleavage of the Carbon-Nitrogen Bond. ACS Sustainable Chem. Eng. 2015, 3, 3332-3337. [0062] [9] M. Das, R. Chacko, S. Varughese. An Efficient Method of Recycling of CFRP Waste Using Peracetic Acid. ACS Sustainable Chem. Eng. 2018, 6(2), 1564-1571, DOI: 10.1021/acssuschemeng.7b01456. [0063] [10] K. Yu, Q. Shi, M. L. Dunn, T. Wang, H. J. Qi. Carbon Fiber Reinforced Thermoset Composite with Near 100% Recyclability. Adv. Funct. Mater. 2016, 26, 6098-6106. [0064] [11] W. Guo, S. Bai, Y. Ye and L. Zhu. Recycling carbon fiber-reinforced polymers by pyrolysis and reused to prepare short-cut fiber C/C composite. Journal of Reinforced Plastics & Composites. 2019 0(0) 1-9. [0065] [12] K. Kim, J. Jeong, K. An, B. Kim. A Low Energy Recycling Technique of Carbon Fibers-Reinforced Epoxy Matrix Composites. Ind. Eng. Chem. Res. 2019, 58, 618-624. [0066] [13] M. Limburg, J. Stockschläder, P. Quicker. Thermal treatment of carbon fiber reinforced polymers (Part 1: Recycling). Waste Management & Research 2019, Vol. 37(1) Supplement 73-82. [0067] [14] Y. Liu, M. Farnsworth, A. Tiwari. A review of optimisation techniques used in the composite recycling area: State-of-the-art and steps towards a research agenda. Journal of Cleaner Production 140 (2017) 1775-1781. [0068] [15] M. Overcash, J. Twomey, E. Asmatulu, E. Vozzola, E. Griffing. Thermoset composite recycling—Driving forces, development, and evolution of new opportunities. Journal of Composite Materials. 2018, Vol. 52(8) 1033-1043. [0069] [16] J. Wellekotter, S. Baz, J. Schwingel, G. Gresser, P. Middendorf, C. Bonten. Recycling of composites—A new approach minimizes downgrading. AIP Conference Proceedings 2055, 060009 (2019). [0070] [17] WO2017/106243 A1. [0071] [18] K. Pender and L. Yang. Investigation of Catalyzed Thermal Recycling for Glass Fiber-Reinforced Epoxy Using Fluidized Bed Process. Polymer Composites 2019 1-10. [0072] [19] WO2017/175100 A1. [0073] [20] WO2018/206788 A1. [0074] [21] P. Dohlert, J. Pfrommer, S. Enthaler. Recycling Concept for End-of-Life Silicones: Boron Trifluoride Diethyl Etherate as Depolymerization Reagent to Produce Difluorodimethylsilane as Useful Commodity. ACS Sustainable Chem. Eng. 2015, 3, 163-169. [0075] [22] N. M. R. Chipa; V. P. Jatakiya; P. A. Gediya; S. M. Patel, and D. J. Sen. Green Chemistry: an Unique Relationship Between Waste and Recycling, Int. J. Adv. Pharm. Res., 2013, 4(7), 2000-2008. [0076] [23] Li, F. Xia, J.; Xiong, Y.; Tang, X.; Cheng, Y. Process for Preparation of Epichlorohydrin and Dichloropropanol Intermediates, Faming Zhuanli Shenging, 101195607, 2008. [0077] [24] Al-Juaid, S. S.; Eaborn, C.; El-Kheli, M. N. A.; Hitchcock, P. B.; Lickiss, P. D.; Molla, M. E.; Smith, J. D.; Zora, J. A. Tris(trimethylsilyl)methyl and Tris(dimethylphenylsilyl)methyl Derivatives of Boron. Crystal Structures of Dihydroxy[tris(trimethylsilyl)methyl]borane and of the Lithium-Boron Complex [(MeOH)2Li(μ-OMe)2B(OMe)2]. J. Chem. Soc., Dalton Trans.: Inorganic Chem., 1989, 3, 447-52 [0078] [25] Bayo-Bangoura, M.; Bayo, K.; Mossoyan-Deneux, M. Synthèse de la Chlorosousphthalocyanine de Bore a Partir de L′acide 1,4-Diboronique Benzène. Comptes Rendus Chimie 2011,14(6), 530-533. [0079] [26] Ishihara, K.; Kondo, S.; Yamamoto, H. Scope and Limitations of Chiral B-[3,5-Bis(trifluoromethyl)phenyl]oxazaborolidine Catalyst for Use in the Mukaiyama Aldol Reaction. J. Org. Chem., 2000, 65(26), 9125-9128.

[0080] The features disclosed in the foregoing description and in the dependent claims may, both separately and in any combination thereof, be material for realizing the aspects of the disclosure made in the independent claims, in diverse forms thereof.

TABLE-US-00002 Name and description of used materials Compounds/ materials name Description/Composition/Mixture G10 bromine-free glass fiber reinforced epoxy composite DE104 glass fiber reinforced epoxy composite with flame-retardant tetrabromobisphenol A recyclate glass fiber reinforced epoxy composite with flame-retardant MPM tetrabromobisphenol A from circuit boards CRP carbon fiber reinforced epoxy composite from a wind turbine with 70% content of carbon fiber BPA bisphenol A, 4,4′-(propane-2,2-diyl)diphenol VZ-BPA a BPA-sample for NMR spectra TBBA tetrabromobisphenol A, 4,4′-(propane-2,2-diyl)bis(2,6- dibromophenol) VZ2628-1 a sample of BPA dimethyl ether for NMR spectra VZ2565 a sample of TBBA diethyl ether for NMR spectra VZ-G10-4-1 a mixture of BPA, phenol and 1,3-dichloropropan-2-ol (relation 1.00:0.50:1.12, respectively) from cleavage of G10 with BCl3 VZ-G10-4-2 a mixture of oligomers with small amounts of BPA and phenol from cleavage of G10 with BCl3 VZ-DE-1-1 1,3-dichloropropan-2-ol and a mixture of bisphenol derivatives (first fraction after treatment of DE104 with BCl.sub.3) VZ-DE-1-2 BPA, TBBA and small impurities of 1,3-dichloropropan-2-ol (second fraction after treatment of DE104 with BCl.sub.3) VZ-DE-1-3 oligomers and polymers (third fraction after treatment of DE104 with BCl.sub.3) VZ-DE-1-4 oligomers and polymers (fourth fraction after treatment of DE104 with BCl.sub.3) VZ-MPM- a mixture of BPA, TBBA and 1,3-dichloropropan-2-ol C3 (relation 1:0.5:2, respectively) from cleavage of recyclate MPM with BCl3 VZ-MPM- a mixture of BPA, TBBA and 1,2,3-tribromopropane BBr-2 (relation 1:0.44:1.88, respectively) from treatment of recyclate MPM with BBr3 VZ-CFK-1 a mixture of BPA, 1,2-dibromopropan-2-ol and small impurities of undefined compounds from treatment of CRP with BBr.sub.3 VZ-CFK-V3 a mixture of BPA and polymer from treatment of CRP with BCl.sub.3