การศึกษาเบื้องต้นในการใช้กากกาแฟเป็นสารตัวเติมในยางธรรมชาติ

Abstract

The objective of this research was to study the effects of particle size and content of spent coffee ground (SCG) use as efficient filler for indoor flooring foam rubber. The properties of flooring foam rubber were compared with the commercial EVA foam. In this study, influence of the average of particle size at 80 µm and 425 µm with the SCG as filler, epoxidized natural rubber contain 25 and 50% mole of epoxide content (ENR50) as compatibilizer, type of ENR25 and ENR50 were investigated. The results showed that the cure time were increased with reducing the particle size and increasing of SCG content. The mechanical properties i.e., tensile strength, elongation at break and tear strength with a small particle size were 30-50% higher than larger particle size for increased SCG content. Increasing the SCG content provided a longer cure time. Also, the tensile strength, elongation at break, and tear strength tend to decease. Using ENR50 as compatibilizer showed a shorter scorch time, but with longer cure time compared to not using a compatibilizer. Moreover, using compatibilizer improved the tensile strength by 30-50% and tear strengths were higher by 20-15% with increasing the SCG content, respectively. In addition, the type of ENR 25 and ENR50 were studied instead of natural rubber grade STR5L. The ENR50 gave a shorter scorch time but a longer cure time than ENR25 and STR5L. However, ENR50 improved the mechanical properties only 10% higher than ENR25. Therefore, the formula suitable for preparing flooring foam rubber was the ENR25. The blowing agent (Super cell EVA-B3) with 5 phr and SCG 25 phr resulted in a homogenous cell foam with density of 45 kg/m3 Comparing the mechanical properties of foam rubber with the commercial EVA foam (EVA 45), the tensile strength and tear strength of foam rubber between 30-50% higher. In addition, the rubber foam had the compression set change lower than 30%. The result revealed that the rubber foam use SCG as filler had the completion potential with the commercial EVA foam for foam rubber flooring inside the building, and reduce the problem of biomass waste from spent coffee ground.