English Abstract

Structure and Characterization of Insoluble Sulfur Prepared by Melt Electrospinning Method

Naoki TERADA *1 *2
Katsushige KOUGE *1
Kazuhide UENO *3
Hiromori TSUTSUMI *2
*1:Sanshin Chemical Industry Co., Yanai, Yamaguchi, Japan
*2:Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Ube, Yamaguchi, Japan
*3:Faculty of Engineering, Yokohama National University, Hodogaya-ku,Yokohama, Japan
Nippon Gomu Kyokaishi,(2017),90(11),497-504 Original Paper in Japanese

Structure of insoluble sulfur (S) is linear chain structure which connects sulfur atoms each other. High thermal stable S is indispensable for a rubber vulcanizing agent. High conversion from elemental sulfur (S8) to S is also cost-effective on commercial point of view. Commercial S for a rubber vulcanizing agent has been prepared by quenching of molten sulfur. We prepared S by using melt electrospinning technique. Melt electrospinning method is normally applied to prepare very thin polymer fibers which have high-oriented polymer chains in them. The diameter of the resulted fibrous sulfur was about 20 m and they showed some rough surfaces. Conversion of S from S8, structure and thermal stability of the melt-electrospun S were also investigated. Higher molten temperature of electrospun process provided higher conversion of S. The conversion of electrospun S was comparable to that of commercial S. The addition of iodine to molten sulfur enhanced the thermal stability of the resulted S under the specific molten temperature; however, this value was lower than that of commercial S. Post-heating process of the melt-electrospun fibrous sulfur was effective for enhancing thermal stability of the electrospun S.

Keywords: Insoluble Sulfur, Polymer Sulfur, Rubber Vulcanizing Agent, Melt Electrospinning Method, Thermal Stability, Conversion from Sulfur