Surface and Dynamic Viscoelastic Properties of Cork from Quercus variabilis

Jingjing Li, Junjie Bi, Xiaozhou Song, Wencheng Qu, Dongmei Liu

Abstract


Surface and dynamic viscoelastic properties of the reproduction cork from Quercues variabilis were studied in detail. There were 16 chemical elements in the Q. variabilis cork determined by the energy dispersive spectrometric (EDS) spectrum, and the contents of C and O were the highest. The mean colorimetric parameters L*, a*, and b* were 60.8, 14.0, and 30.6, respectively. The surface contact angles of Quercus variabilis cork were measured using an automatic contact angle meter. Three different types of liquid media (distilled water, formamide, and diiodomethane) were respectively dropped on the surface of corks using a microsyringe. The initial contact angles of water, formamide, and diiodomethane on the cork surface were 112.0°, 85.1°, and 75.2°, and the corresponding values decreased to 102.1°, 30.7°, and 72.1° when the liquids permeated the cork surface for 10 s. The moisture content values were 4.3%, 6.0%, and 9.0% when the dry cork samples were placed in the relative humidity conditions of 45%, 65%, and 85%, respectively, for 30 days. FT-IR spectra indicated the content of suberin in the sclereids and lenticels was much less than the content found in the pure corks. In the dynamic mechanical analysis (DMA) spectrum, three obvious relaxation processes could be observed in the tan δ curve.

Keywords


Quercus variabilis; Cork; Surface properties; Viscoelasticity

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126