Microwave-irradiated tanning reaction of aluminum with collagen
Given the toxicity of chrome tanning in leather industry, ecologically compatible alternatives are intensively researched, in particular on the side of aluminum tanning. Herein, the tanning reaction of aluminum with collagen was investigated using microwave irradiation as a new heating method, and the traditional water bath heating (WBH) was used as control. Results from dynamic light scattering and very-positive differential scanning calorimetry (DSC) analysis reveal that, microwave heating led to larger particle size and increased main denaturing transition temperature of collagen clusters crosslinked by aluminum sulfate. The aluminum-tanned collagen products obtained under microwave and WBH methods were further compared and characterized using many techniques including circular dichroism, fluorescence spectroscopy, atomic force microscope, and Fourier transform infrared spectroscopy, DSC, and thermogravimetry. Results verified that both heating methods accelerate the crosslinking reaction of aluminum with collagen and increase the crosslinking degrees. The crosslinked products exhibited improved thermal stability, but no change was observed concerning the binding mode of aluminum with collagen. However, compared to WBH microwave heating has a more positive effect on the aluminum-tanning processes for the improvement of collagen crosslinking processes and product performances, probably due to both thermal and nonthermal effects of microwave irradiation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137 , 48682.
危险品化学品经营许可证（带存储）