Fast polymerization at low temperature of an infrared radiation cured epoxy-amine adhesive

Abstract

In the industry, the cure time of two-component adhesives is very important for a cost-effective manufacturing. Too fast, it does not favor the application of the product and the control of bonded joints. Too slow, it leads to long process times and too high process costs. The best compromises are two-component adhesives that cure slowly at room temperature and can reach full polymerization in minutes, on demand.In this paper, the curing behavior of a model poly-epoxide adhesive (a stoichiometric mixture of a pure epoxy and amine) polymerized with infrared radiation will be studied. The kinetic follow-up of this polymerization will be carried out by thermal analysis (determination of the residual heat peak by Differential Scanning Calorimetry-DSC). This study paves the way to a cold and universal cure-on-demand process, 2 which means achieved in few minutes at low temperature without any initiators, catalysts or accelerators. Basically, infrared curing can be possible thanks to an increase in temperature (called thermal effect). But it has been shown that a "non-thermal effect" could also be involved in accelerating kinetics with infrared. This increase due to a non-thermal effect, suggested as a function of the infrared radiative flux, has been shown to be possible thanks to the absorption of infrared radiation, leading to a reduction in the energy barrier of the primary epoxy/amine reaction.

Recent advances on ferrocene-based photoinitiating systems

“…[8][9] Recently, photopolymerization has known a revival of interest with the development of the 3D/4D printing technologies, and a great deal of efforts has thus been devoted to elaborate dyes strongly absorbing at 405 nm, which is the wavelength currently under use in 3D printers. [10][11][12][13][14][15][16][17][18] With aim at reducing the environmental impact of photopolymerization, greener processes are now widely explored and the use of biosourced photoinitiators and monomers, [19][20][21][22][23][24][25][26][27][28][29] or the use of sunlight as the irradiation source to initiate polymerization processes are now extensively studied. [30][31][32][33][34][35] The progress in these two fields is considerable.…”

Mechanical and Thermal Properties of Epoxy/Poly(Styrene‐co‐Acrylonitrile) (SAN)/Organoclay Nanocomposites

“…Epoxy resins belong to the class of thermosets, which is extensively used in varying engineering applications ranging from electronics to automobile. [1][2][3][4] As the cure reaction progresses, the crosslink density of the epoxy resin increased, which lead to the brittleness of the material and hinders the end use applications. This resulted in the concern over the ultimate properties of the cross-linked epoxy.…”

Recent advances on visible light photoinitiators of polymerization based on Indane-1,3-dione and related derivatives

“…Parallel to this, emerging applications such as 3D and 4D printing have clearly provided a revival of interest for this polymerization technique. [23][24][25][26][27][28][29] Figure 1. Light penetration within a photocurable resin composed of a polystyrene latex with an average diameter of 112 nm.…”