Objective: Synthesize and characterize a monomethacrylated monomer functionalized with ester and phosphate groups and study the influence in the degree of conversion.
Method: The monomer was prepared by the reaction of the intermediate CMEE-2 (product of the reaction between caprolactone 2-(methacryloyloxy) ethyl ester with chloroacetyl chloride) with trimethyl phosphite (P(OCH3)3), which were stirred during 24 hours at 80oC, generating a phosphonated derivative of caprolactone 2-(methacryloyloxy) ethyl ester (CMEE-PMe). After purification, the product was identified by NMR spectra. The following unfilled resinous groups were prepared containing camphorquinone and N,N-dimethylaminobenzoic acid as photo and co-initiators, respectively: i) CMEE-PMe/GDMA 80:20 (w:w); ii) GDMA, where GDMA is glyceroldimethacrylate. The degree of conversion (DG, n=5) was determined using samples irradiated during 20s with a blue light source of 1250 mW/cm2 (Kerr, Demetron LC) and analyzed through FTIR spectra (FTIR-8300 Shimadzu). The data were analyzed statistically using ANOVA/Scheffe's post-hoc test at significance level 0.05.
Result: CMEE-PMe was easily synthesized with a yield of 30 %. The NMR spectra confirmed the chemical structure of CMEE-PMe. The following means (SD) of DG were obtained for group i and ii respectively, 63.9 (1.9); 40.9 (2.4). The data are statistically different indicating that CMEE-PMe increased the reactivity of the blend containing GDMA, a dimethacrylated monomer.
Conclusion: An easy chemical method was obtained to synthesize CMEE-PMe. This functionalized monomethacrylated monomer presents optimistic preliminary results as a novel material for application in dental materials. Acknowledge: CNPq and FGM.