Affiliation:
1. Key Laboratory of Special Functional Molecular Materials, Ministry of Education, College of Chemistry Zhengzhou University Zhengzhou China
Abstract
AbstractSingle‐component epoxy adhesives are widely used in various fields due to their simple operation process and excellent bonding properties. However, the excessively high curing temperature of the traditional single‐component epoxy adhesives may easily damage the electronic devices, limiting their further application. Hence, it is of great significance to develop the low‐temperature‐curing single‐component epoxy adhesives. However, the room temperature storage stability of low‐temperature curing system is generally poor. This work selected epoxy resin (EPON‐828), pentaerythritol tetra (3‐mercaptopropionate) (PETMP), 1‐benzylimidazole (1‐BMZ), and stabilizer (salicylic acid) as materials to prepare low‐temperature curing single‐component epoxy adhesives. In order to improve the storage stability of the system, polycarbonate (PCM‐A‐37) with low molecular weight was employed to coat the accelerator 1‐BMZ by physical sedimentation. The results showed that the room temperature storage period of the system reached 140 h, which was 2.18 times longer than before coating, and the curing temperature of 75°C was determined through DSC curves fitting. The epoxy adhesives have been completely cured at 75°C for 5 h, and shear strength reached 10.20 ± 0.51 MPa, which was not significantly different from that of the system with uncoated accelerators. We believe our paradigm can provide a feasible approach for preparing low‐temperature curing single‐component epoxy adhesives, and has reference significance for the preparation of single‐component adhesives in other systems, too.