Influence of curing accelerator for cyanoacrylate glues on physical properties of adhesive resins

ABSTRACT

The objectives of this study were to evaluate the effect of a curing accelerator (CA) on the ultimate tensile strength (UTS) and degree of conversion (DC) of two adhesive systems, Single Bond and Clearfil SE Bond, as well as to identify the composition of the CA hour-glass adhesive resin samples with a cross sectional area of 0,8 mm² at the "neck" were tested in tension using a Universal Testing Machine. Fourier transform infrared spectroscopy (FTIR) was used to analyse thin films of each adhesive resin. All samples were stored in the dark for 24 hours before they were tested. During the UTS and FTIR analyses, the contact of the CA with samples was either avoided or not. The gas chromatography mass spectrocopy (GC-MS) and the nuclear magnetic resonance (NMR) analyses determined the molecular weight and structure of the CA. UTS and DC were analyzed by ANOVA and Tukey's test at 95% of confidence. The use of the CA did not affect the UST (p=0.5996) but increased the DC of the samples (p<0.0001). The compound identified by GC-MS and NMR was N-dimethyl p-toluidine. The application of CA in microtensile bond strength methodology raises concern regarding its effects on poorly polymerized adhesive systems.