Materials Chemistry and Physics, Vol.199, 387-392, 2017
Solvent influence on crosslinking and surface characteristics of Urushi films
We here demonstrate the effects of solvents on crosslinking and surface characteristics of Urushi (Oriental lacquer) films. We aimed to clarify the influence of solvents on crosslinking of Urushi by comparing normal Urushi films with Urushi films blended with three types of solvents, camphor, turpentine, and methanol, by using differential scanning calorimetry (DSC). In addition, we evaluated the effects of ultraviolet (UV) irradiation on crosslinking and surface characteristics of Urushi films using scanning probe microscopy (SPM) and Fourier transform infrared (FTIR) spectroscopy. The DSC results showed that Urushi films blended with camphor had large amounts of non-crosslinked parts compared to films blended with turpentine and methanol. From the results of SPM observations, it was found that surface roughness increased with an increase in UV irradiation time. Furthermore, FTIR results indicated that C=0 stretching peaks attributed to the curing reaction increased with an increase in UV irradiation time. This tendency of increasing peak intensity is consistent with the change in surface roughness induced by UV irradiation. (C) 2017 Elsevier B.V. All rights reserved.