The contents of grafted PCL in MCC-g-PCL copolymers were characterized by 1H nuclear magnetic resonance (NMR) spectroscopy. 1H NMR spectra were recorded at 400 MHz using a Bruker BioSpin NMR spectrometer (Bruker Company, Germany) in dimethyl sulfoxide-d6 (DMSO-d6) solvent. The chemical shifts were calibrated against the internal standard signals of tetramethysilane (TMS). 13C NMR spectra were acquired on a Bruker BioSpin NMR apparatus at 100 MHz, at ambient temperature, using TMS as the internal standard and DMSO-d6 as solvent.
Raman spectroscopy was conducted on a Renishaw InVia Reflex Raman system. The Raman scattering was excited using a diode laser at a wavelength of 785 nm. The laser beam was focused on the sample with a 100 an0.85 microscope objective. The laser power at the sample was 320 mW. The exposure was 10 s and two accumulations of Raman measurements were carried out. In addition, an optical microscope was coupled to the system.
The molecular weight and molecular weight distribution of prepared MCC-g-PCL were measured on a Waters 5510 gel permeation chromatograph (U.S.A.). DMSO was used as eluent at a flow rate of 0.5 mL min−1 at 50 °C. The SEC system was calibrated with linear polystyrene standards.
Raman spectroscopy was conducted on a Renishaw InVia Reflex Raman system. The Raman scattering was excited using a diode laser at a wavelength of 785 nm. The laser beam was focused on the sample with a 100 an0.85 microscope objective. The laser power at the sample was 320 mW. The exposure was 10 s and two accumulations of Raman measurements were carried out. In addition, an optical microscope was coupled to the system.
The molecular weight and molecular weight distribution of prepared MCC-g-PCL were measured on a Waters 5510 gel permeation chromatograph (U.S.A.). DMSO was used as eluent at a flow rate of 0.5 mL min−1 at 50 °C. The SEC system was calibrated with linear polystyrene standards.