Irgacure 127

• CAS: 474510-57-1
• Catalog Number: ACM474510571
• Category: Main Products
• Molecular Weight: 340.41
• Molecular Formula: C21H24O4
• Synonyms: 1,1'-(methylenebis(4,1-phenylene))bis(2-hydroxy-2-methylpropan-1-one)

Case Study

Effect of UV-Photoinitiator (e.g. Irgacure 127) on Thermally Curable Self-Adhesive Structural Tapes of Cross-Linked Acrylate Copolymers

Kowalczyk, Agnieszka, et al. International Journal of Adhesion and Adhesives, 2018, 85, 286-292.

The development of thermally curable self-adhesive structural tapes (SATs) involved the UV irradiation of a photoreactive epoxyacrylate copolymer which was combined with a bisphenol-A type epoxy resin and a cationic hardener. Researchers introduced 2-hydroxyethyl methacrylate phosphate ester (G40) into the copolymer during the modification phase. The study examined the impact of G40 on the self-adhesive properties, thermal reactivity of the SATs, and the mechanical characteristics of thermally cured aluminum-SAT-aluminum overlap joints.
A group of compounds were tested as UV photoinitiators for G40 including Irgacure 184 (B), Irgacure 127 (C), Irgacure 2959 (D), Irgacure 754 (E), Irgacure TPO-L (F), Irgacure 819 (G), and Darocure 1173 (H).
Key Findings
The inclusion of G40 enhanced adhesion between the SATs and aluminum; however, the UV irradiation parameters-specifically the duration and intensity of the UV dose applied during SAT preparation-were found to be critical to this property. The addition of G40 resulted in a substantial enhancement of shear strength for thermally cured joints while simultaneously influencing both the epoxy group conversion rate and the crosslinking extent in SATs.
The α-hydroxyketone photoinitiators Irgacure 127 and Irgacure 184 demonstrated higher efficiency in triggering the photopolymerization of G40 than all other photoinitiators tested. The adhesive formulation containing G40 reaches full conversion after 60 seconds of exposure to UV light from a medium pressure mercury lamp which delivers a UV dose of 15 J/cm2.