An electrochemical investigation on the role of saccharin in the cure chemistry of anaerobic adhesives

Advances in anaerobic and cyanoacrylate adhesives

“…the initiator system includes saccharin (benzosulfimide) (1), a reducing agent, such as an N,N-dialkyl arylamine, (2), or acetyl phenylhydrazine (aPH), (3), and a stable peroxide, such as cumene hydroperoxide (cHP), (4). Despite a number of studies which investigated the redox initiation mechanism, it has still not been completely resolved (Beaunez et al, 1994a(Beaunez et al, , 1994bBoerio et al, 1990;George et al, 1997George et al, , 1998aGeorge et al, , 1998bGeorge et al, , 2000Humphreys, 1983;McGettrick et al, 1994;moane et al, 1999;Okamoto, 1990aOkamoto, , 1990braftery et al, 1997a, 1997bSmith, 1992;Wellmann and Brockmann, 1994). Although all of them agree that there is a complex interaction of the various cure components, there is no complete agreement on the specific details.…”

Mechanism of Initiation of the Curing of Anaerobic Adhesives

“…By the polarographic method it has also been demonstrated [23] that DMPT can reduce Fe +3 . At the same time, even with a high CHP concentration in the absence of DMPT, there is no reduction in the Fe +3 concentration, i.e.…”

“…The role of the anion in copper salt is shown in reference [23], in which, by means of cyclic voltamperometry, it was established that Cu(II), in saccharinate form, possesses a considerably narrower reduction potential (-1 mV) by comparison with the acetate (-43 mV) and sulphate (-37 mV). George et al [25] likewise revealed the effect of the copper anion on the curing rate of ACs: under identical conditions with Cu(I) chloride, the gelation time of the AC was 15 min, as opposed to 1 min with Cu(I) saccharinate.…”

“…It has been suggested [26] that, when DMPT interacts with SBI, so-called aminal can be formed: which acts as a reducing agent. Aminal obtained by countersynthesis was studied in reference [23], in which it was established that it does not reduce Fe(III) even in the presence of SBI but is a strong reducing agent for Cu(II). In the opinion of George et al [25], aminal acts as an acid, dissolving copper.…”