Nanomechanical Properties of Photo-Cured Cyanoacrylate Bioadhesives Crosslinked by TMPTMA or POSS Nanostructures

The surface modulus and hardness of photo-crosslinkable cyanoacrylate bioadhesives containing TMPTMA and POSS as crosslinking agents were studied using nanoindentation technique. Adhesives containing 2-octyl cyanoacrylate (2-OCA) and different percentages of POSS nanostructures and TMPTMA as crosslinking agents were prepared. 1-Phenyl-1,2-propanedione (PPD) was incorporated as photo-initiator into the adhesive in 4 wt%. Mechanical properties of the surface of the adhesives were measured using nanoindentation technique applying a Berkovich tip. The results (three replicates) were analyzed and compared using one-way ANOVA and Tukey test at a significance level of 0.05. The results showed that by incorporation of crosslinking agents, surface modulus and hardness increased and force loss during holding decreased. The incorporation of crosslinking agents into the adhesives enhanced their elastic properties. The surface modulus and hardness increased by increasing crosslinking concentration. The results also indicated that the elastic work increased, and plastic work dropped due to increasing crosslinking density. The samples which had been stored in water for 24 h before the tests, showed reduced elastic properties due to the plasticization effect of water.