Influence of Methacrylate and Vinyl Monomers on Radical Bulk Photopolymerization Process and Properties of Epoxy-Acrylate Structural Adhesives

Abstract

In this paper, epoxy-acrylate structural adhesives tapes (SATs) were obtained from Bisphenol A-based liquid epoxy resin and epoxy acrylic resins (EARs). A new method of EARs preparation, i.e., the free radical bulk photopolymerization process (FRBP), was studied in detail. The influence of methacrylic monomers (methyl methacrylate, ethyl methacrylate, butyl methacrylate, lauryl methacrylate, (2-acetoacetoxy)ethyl methacrylate) and vinyl monomers (N-vinylpyrrolidone and styrene) on the FRBP process of base monomers (i.e., butyl acrylate, glycidyl methacrylate and 2-hydroxyethyl acrylate) was investigated. The kinetics of photopolymerization process was monitored by photo-differential scanning calorimetry method. The properties of the obtained EARs (viscosity and average molecular weights), as well as monomers conversion using 1H NMR, were determined. It was revealed that styrene significantly decreases the photopolymerization rate and increases the final monomers conversion (+27%). However, the resulting tetrapolymers BA-co-GMA-co-HEA-co-STY have low molecular weights and low polydispersity (2.2). Methacrylate monomers with shorter aliphatic chains (<C4) also decrease the rate of photopolymerization due to the length of the aliphatic chain increasing. Surprisingly, the best results of adhesion to steel and shear strength were obtained for SAT based on epoxy acrylate resin with styrene (11 N/25 mm and 20.8 MPa, respectively). However, the thermomechanical properties of SAT with styrene were weaker than those with methacrylates.

Hydrogels based on poly(2-hydroxyethyl methacrylate) and nettle extract

“…In the case of the HEMA monomer, we find that the gel effect occurs much earlier. This is related to the presence of a hydroxyl group, which is confirmed by our previous research on the influence of the monomer structure on the bulk photopolymerization process [42]. As can be seen, a higher dose of photoinitiator causes generally rapid photopolymerization.…”

Light‐Mediated Polymerization Catalyzed by Carbon Nanomaterials

“…Light‐mediated polymerization has received increasing interest in polymer synthesis for use in diverse fields [1–19] . Examples include, but not limited to lithography, [4,9,20–22] printing based on 2D, [4,15,23,24] 3D [4,6,8,25–52] or 4D [27–29,53,54] patterning, holographic recording, [16,55,56] fabrication of prosthesis, [57] dental composites, [38,46,58] anti‐counterfeiting materials, [59] inks, [4,60,61] surface modification of solidified coatings [4,13,14,62–68] or adhesives [4,69–72] . Formulating of light‐sensitive compositions based on Chemistry 4.0, which was defined by the VCI in Germany as a combination of artificial intelligence (AI) and central data management, [73] can be seen as an additional challenging aspect [18] .…”

Lichtinduzierte Polymerisation katalysiert durch Kohlenstoff‐Nanomaterialien

“…Lichtunterstützte Polymerisationen sind von wachsendem Interesse für die Synthese von Polymeren und deren Anwendung auf verschiedenen Gebieten [1–19] . Ausgewählte Beispiele beinhalten die Lithographie, [4,9,20–22] den Druck von 2D, [4,15,23,24] 3D [4,6,8,25–52] oder 4D [27–29,53,54] Mustern, die holographische Aufzeichnung, [16,55,56] die Herstellung von Prothesen, [57] Dentalkompositen, [38,46,58] fälschungssicheren Materialien, [59] Farben, [4,60,61] die Oberflächenmodifizierung von verfestigten Überzügen [4,13,14,62–68] oder von Klebstoffen, [4,69–72] wobei die Anwendungen nicht auf die genannten Beispiele beschränkt sind. Die Formulierung von lichtempfindlichen Zusammensetzungen basiert auf Chemie 4.0, was durch den VCI (Verband der chemischen Industrie) in Deutschland als eine Kombination von künstlicher Intelligenz (KI) und zentralem Datenmanagement definiert ist [73] und als ein zusätzlicher herausragender Aspekt betrachtet werden kann [18] .…”