Chemical Carbonization of Paper Made from Wood Pulp without Thermal Decomposition Using a Catalyst and Structural Properties of the Carbonized Paper

Paper is composed of plant fibers obtained from both wood and non-wood pulp, and the chemical component is mainly cellulose. It is well-known that cellulosic materials are very hard to carbonize at high temperatures because they decompose thermally before forming carbon materials. We have tried chemical carbonization of wood-pulp paper without thermal decomposition using a catalyst to prepare two-dimensional carbon materials. Three kinds of paper (called LBKP-papers here after) made from bleached kraft hardwood pulp having 0.7～0.76 mm in length weighted mean fiber length and about 260 μm in thickness was used for the chemical carbonization in this work. In the three kinds of LBKP-papers, one includes a wet paper strengthening agent and another one has a little different distribution of the fiber length. One of organic sulfonic acids, methane sulfonic acid (MSA) was used as a catalyst for the carbonization. The LBKP-papers were treated in 1 mol MSA aqueous solution for 5 min and were dried at room temperature. The MSA-treated LBKP-papers were carbonized at 800℃ under an Ar gas atmosphere. Structural and physical properties of carbonized LBKP-papers were investigated. All of the LBKP-papers carbonized at 800℃ were amorphous and then were crystallized with heat-treatment at higher temperatures, being independent of the wet paper strengthening and the different fiber length distribution. A graphitic structure was developed in carbonized LBKP papers heat-treated at temperatures higher than 2000℃. Mechanical and electrical conductive properties of the carbonized LBKP papers were improved with the heat-treatment.