Dpx 200

The retardation factor (R_F) of compounds was calculated by tin layered chromatography (TLC). TLC were performed on aluminum plates coated with silica gel 60 F254 (Merck, Poznan, Poland). A UV-254 nm lamp and a solution of phosphoromolybdenic acid (PMA) were used as TLC stains. Flash column chromatography (FCC) was performed using 230–400 mesh silica gel (Fluka). The symbol ø means the diameter of the chromatography column [cm]. The NMR spectra were recorded on a Bruker Avance II 400 (400 MHz) or Bruker DPX 200 (200 MHz) using 5 mm probes operating at 400 MHz (200 MHz) for ¹H NMR, and 101 MHz for ¹³C NMR (DMSO-d₆ or CDCl₃) and 377 MHz for ¹⁹F NMR (CDCl₃) spectra. Chemical shifts were determined relative to tetramethylsilane (TMS) and referenced to the CDCl₃ signals at δ = 7.26 ppm for ¹H and 77.0 ppm for ¹³C spectra. The following abbreviations were used to explain the multiplicities: s (singlet), d (dublet), dd (doublet of doublets), t (triplet), q (quarted), and m (multiplet). IR spectra were recorded on a Nicolet 6700 with DTGS detector. The attenuated total reflectance (ATR) method was used. The melting point (MP) of the synthetized compounds was measured on an SRS MPA120 Ez-Melt apparatus with a temperature increase of 0.5 °C/min and this value was reported to clear point. Compound 1 was distilled using a B-585 Kugelrohr apparatus (Büchi, Flawil, Switzerland).

All commercial reagents were used as received. Solvents were analytical grade and purified before use. Moisture-sensitive liquids were transferred using a gas-tight syringe through a rubber septum and stored under argon. Nuclear magnetic resonance (NMR) spectra were determined on Bruker DPX-200 and DRX-400 spectrometers. Chemical shifts (δ) are stated in parts per million (ppm) and coupling constants (J) in Hertz (Hz). Tetramethylsilane (TMS) was used as the internal reference standard for ¹H NMR, and CDCl₃ for ¹³C NMR. The following abbreviations are used in the description of NMR data: s = singlet, bs = broad singlet, d = doublet, t = triple, q = quartet, m = multiplet.

For FTIR analysis, The KBr pressed disc technique (2–4 mg of sample and 200 mg of KBr) was used. Data acquired in Shimadzu 8400 FT-IR spectrophotometer. Absorbance spectra were obtained from 4000 to 400 cm-1 with a 4 cm-1 resolution, Background spectra were also collected and subtracted. The ¹H spectra were taken on a Bruker DPX200 (500 MHz for 13 C and 200 MHz for 1 H) in D₂O solvent using tetramethylsilane (TMS) as an internal standard. Both cases 5 mg/mL concentrated solutions were prepared. All signals were referenced to TMS within ± 0.1 ppm. The thermo oxidative stability of pure lignin and lig-g-POZ with different weight (%) lignin content copolymer were carried out using a TGA Q50 thermal analyzer of TA Instruments, USA. All the experiments were performed by heating the sample at a rate of 10 °C/min, in nitrogen atmosphere, from room temperature to 600 °C. DSC studies of the pure lignin and lig-g-POZ copolymer with different weight (%) lignin content were performed using a DSC Q100, of TA instruments make, USA. Approximately 10 mg of the samples was placed in an aluminum crimple and sealed with the help of a hand press prior to placing it on the sample platform of the instrument. The scanning was carried out in the temperature range of 30 °C to 200 °C at a heating rate of 10 °C/min in a stream of continuous supply of dry nitrogen.

All ¹H-NMR spectra were recorded with a DPX200 or a DRX400 spectrometer from Bruker with a ¹H resonance frequency of 200.13 and 400.13 MHz, respectively. The residual solvent peak was used as internal standard for calibration of chemical shifts. Ultraviolet–visible (UV–vis) measurements were performed with a Cary 60 spectrophotometer from Agilent Technologies in quartz cuvettes with an optical path length of 1 cm. Reflection Fourier transform infrared (FTIR) spectroscopy measurements were conducted on a Nicolet iS50 FTIR spectrometer or a Nicolet iN10 FTIR microscope from Thermo Fisher Scientific. Samples were prepared as thin films on corresponding substrates by a drop cast process from organic solvents (ethanol or acetone).