Research on the Application Properties of Tpe/Ommt as Mold Materials

Abstract

The aim of this work was to select one type of polymer as an alternative to room-temperature-vulcanizated silicone rubber (RTV) which was used in the preparation of rubber molds.

Thermoplastic elastomer (TPE) and its organo-montmorillonite (OMMT) filled composites were chosen as candidates. Their structure and properties were researched and compared. The properties such as tensile strength, elongation at break, dimensional stability, and thermal stability were studied. The composite with 1 wt% OMMT showed the highest tensile strength and elongation at break, 10.9 MPa and 1313.6%, which was 172.5% and 30.3% higher than that of pure RTV. In addition, this TPE composite exhibited excellent thermal and dimensional stability. At room temperature, the coefficient of linear expansion (COLE) and coefficient of volume expansion (COVE) of the TPE/OMMT-1 wt% was 2.3×10⁻⁵ and 7.2×10⁻⁴, respectively. This was 87% and 86% lower compared to that of pure RTV, 1.7×10⁻⁴ and 5.1×10⁻³. This dimensional stability was superior to the pure RTV, indicating this composite can be used as an alternative to RTV as mold material to improve the texture fineness of the culture stone. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used in the investigation of the microtopography of the TPE composites. It was revealed that the layered silicates exhibited partial exfoliation with the addition of 1 wt% OMMT in the matrix.