Pyrolysis behavior of Asian lacquer film in the presence of carbon nanotubes with potential application as a new sampling method

• Published in: Journal of analytical and applied pyrolysis 2019-09, Vol.142, p.104637, Article 104637
• Main Authors: Nagai, Yoshitaka, Sato, Fumiya, Okamoto, Shun, Kamiya, Yoshimi, Honda, Takayuki
• Format: Article
• Language: English
• Subjects: Analytical pyrolysis; Asian lacquer; Carbon nanotube; Gecko tape; Py–GC/MS; Sampling tool
• ISSN: 0165-2370; 1873-250X
• DOI: 10.1016/j.jaap.2019.104637

•Pyrolyzates characteristics of three Asian lacquer films were detected using a new sampling method.•A difference with respect to the peak intensities of several pyrolyzates was observed.•The T. vernicifluum film was analyzed in the presence of MWCNTs and the mechanism was discussed.•MWCNTs were speculated to promote side-chain cleavage and hydroxyl-group removal. This study aims to report the possibility of applying a sampling method using a carbon nanotube–based sampling tool for pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS) to qualitative analysis of Asian lacquer. This sampling tool comprises multiwalled carbon nanotubes (MWCNTs) and emulates the adhesive mechanism of geckos. To apply this sampling method to lacquer-containing archaeological samples, the films of Toxicodendron vernicifluum, T. succedaneum and Gluta usitata, which are East Asian lacquers, were subjected to Py–GC/MS analysis. Similar to the conventional Py–GC/MS, the pyrolysis product characteristics of the three lacquer films were detected. However, compared with conventional Py–GC/MS, a difference was observed in the peak intensities of several pyrolyzates; this difference revealed the compositional change of pyrolyzates. To investigate the compositional change of pyrolyzates in detail, the T. vernicifluum film was analyzed by Py–GC/MS in the presence of MWCNTs, and the pyrolysis mechanism of T. vernicifluum film was discussed. The results suggest that MWCNTs promote side-chain cleavage and hydroxyl-group removal and alkylcatechols decompose into alkylbenzenes via alkylphenols.