Evaluation of Flow Properties of Adhesives during Reassembly: A Torque Analysis Approach

Evaluation of Flow Properties of Adhesives during Reassembly: A Torque Analysis Approach

Abstract

This study aimed to evaluate the flow characteristics of adhesives during reassembly. A vulcanization analyzer was employed to monitor the torque variation of the adhesive over time at a specific temperature. The experimental results, illustrated in the accompanying figure, reveal a distinct pattern of torque evolution. Initially, the torque rapidly increases within a short period, which is attributed to the material's contact with the rotating plate. Subsequently, as the material softens upon heating, the torque decreases rapidly. This decrease is further amplified by the thermal dissociation of covalent bonds within the adhesive. This dissociation leads to the gradual collapse of the cross-linked network, transitioning it into a linear molecular chain structure. Consequently, the torque continues to decrease until it reaches a stable value. Since torque is directly correlated with the material's viscosity, these findings indicate that the fluid viscosity of the adhesive can rapidly decrease at a specific temperature. This decrease in viscosity facilitates the reassembly process, directly attributed to the dissociation of covalent bonds, thus enabling effective rebonding of the adhesive.