Evaluation of Vulcanization Depth of Thick Rubber Products by Terahertz Radiation

International Rubber Conference

Yasumoto, Y.^1 ; Hirakawa, Y.^1 ; Gondo, T.^1

National Institute of Technology, Kurume College, 1-1-1 Komorino, Kurume

830-8555, Japan^1

关键词: Coefficient of variation;    Cross-linking density;    Cure condition;    Cylindrical products;    Flory-Rehner equation;    Styrene butadiene rubber;    Terahertz radiation;    Terahertz time-domain spectroscopy;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/548/1/012003/pdf
DOI  :  10.1088/1757-899X/548/1/012003

来源: IOP

【 摘 要 】

An evaluation of the vulcanization depth of thick rubber products was performed using terahertz (THz) time-domain spectroscopy. The sample herein was a styrene -butadiene rubber (SBR)-based cylindrical products with a 35 mm diameter and 20 mm thickness, vulcanized under 10 MPa of pressure and a temperature of 150 C. To clarify the vulcanization effect, no carbon black (CB) was included in the sample, because its apparent THz absorbance is extremely large compared with that of polymers and other additives. To perform the THz absorbance imaging, the thick sample was sliced parallel to the upper and lower heating plates of the cure mold into six thin specimens a few millimeters thick. Herein, the samples cured for two different cure times (T90 and T100) were investigated and compared. It was found that the coefficient of variation (CV) of the THz absorbance in the sliced specimens was suitable for evaluating the cure condition in the thick sample. The THz imaging results were used to compare the crosslinking densities of the sliced specimens using the Flory-Rehner equation.