Morphogenesis of Photo-Polymerized Dimethacrylate Networks, Kinetics of Curing and Viscoelastic Parameters

Abstract:

The paper refers to the process of dimethacrylate networks morphogenesis. These stiff and highly cross-linked networks have been extensively used as a polymeric matrix of dental composites for decades. In the study, common co-monomer mixtures used in dental resin formulations were employed. This includes rigid aromatic base monomers, bisphenol A glycerolate dimethacrylate (Bis-GMA) and its ethoxylated alternative (Bis-EMA). Flexible aliphatic monomer, triethylene glycol dimethacrylate (TEGDMA), was used as the viscosity reducer. Kinetics of the polymerization process was studied regarding the structural differences and varying molar ratio of the co-monomers. Kinetic data provided the base for understanding the supra-molecular structure evolution. Consequently, an attempt to quantify the relationship between the resulting network morphology and complex viscoelastic moduli was made. Curing kinetics was studied using differential photo-calorimetry (DPC). Complex modulus was measured using dynamic-mechanical analysis (DMA). Thermal degradation kinetic data (TGA) were used in order to confirm the estimated morphology of cured networks. Reactivity of the monomer is derived from its molecular structure. The potential for non-covalent physical interactions along with monomer backbone rigidity significantly decrease polymerization rate and resulting double bond conversion. The diffusion-controlled kinetics dominates over the chemically controlled kinetics throughout most of the polymerization process. Dilution by the low viscous and flexible monomer shifts the diffusion-controlled kinetics to the later stages of the polymerization. However, the flexibility of the monomer backbone promotes the origination of structural heterogeneities, characterized by micro-gel domains formation. This is associated particularly with the anomalous pendant double bond reactivity and ineffective cross-linking.

• Periodical: Materials Science Forum (Volume 851)
• Pages: 207-214
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.851.207
• Online since: April 2016
• Authors: Zdeněk Bystřický*, Josef Jancar
• Keywords: Curing Kinetics, Dimethacrylate Monomers, Photo-Polymerization, Polymer Network, Viscoelastic Parameters

References

[1] ANDRZEJEWSKA, E. Photopolymerization kinetics of multifunctional monomers. Progress in Polymer Science. 2001, v. 26, pp.605-665.

DOI: 10.1016/s0079-6700(01)00004-1

[2] STANSBURY, J. W. Dimethacrylate network formation and polymer property evolution as determined by the selection of monomers and curing conditions. Dental Materials. 2012, v. 28., pp.13-22.

DOI: 10.1016/j.dental.2011.09.005

[3] BOWEN, R. L. Dental filling material comprising vinyl-silane treated fused silica and a binder consisting of the reaction product of bisphenol and glycidyl methacrylate. US patent. 3, 006, 112. (1962).

[4] ANTONUCCI, J. M., STANSBURY J. W. Molecularly designed dental polymers. Desk Reference of Functional Polymers: Syntheses and Applications. American Chemical Society, 1997, pp.719-737. ISBN 0-8412-3469-8.

[5] FERRACANE, J. L. Resin composites – State of the art. Dental Materials. 2011, v. 27, pp.29-38.

[6] JANCAR, J., WANG W., DIBENEDETTO A. T. On the heterogeneous structure of thermally cured bis-GMA/TEGDMA resins. Journal of Materials Science: Materials in Medicine. 2000, v. 11, pp.675-682.

DOI: 10.1023/a:1008999023271

[7] ANSETH, K. S., WANG, C. M., BOWMAN, C. N. Reaction behavior and kinetic constants for photo-polymerizations of multi (meth)acrylate monomers. Polymer. 1994, v. 15, pp.3243-3250.

DOI: 10.1016/0032-3861(94)90129-5

[8] DICKENS, S. H., STANSBURY J. W., CHOI K. M., FLOYD C. J. E. Photo-polymerization kinetics of methacrylate dental resins. Macromolecules. 2003, v. 36, pp.6043-6053.

DOI: 10.1021/ma021675k

[9] LOVELL, L. G., STANSBURY J. W., SYRPES D. C, BOWMAN C. N. Effects of composition and reactivity on the reaction kinetics of dimethacrylate/dimethacrylate co-polymerizations. Macromolecules. 1999, v. 32, pp.3913-3921.

DOI: 10.1021/ma990258d

[10] ANDRZEJEWSKA, E. Photo-polymerization kinetics of multifunctional monomers. Progress in Polymer Science. 2001, v. 26, pp.605-665.

DOI: 10.1016/s0079-6700(01)00004-1

[11] ABU-ELANAIN, D. A., LEWIS S. H., STANSBURY J. W. Property evolution during vitrification of dimethacrylate photopolymer networks. Dental Materials. 2013, v. 29, pp.1173-1181.

DOI: 10.1016/j.dental.2013.09.002

[12] LEPRINCE, J. G., LAMBLIN G., DEVAUX J., DEWAELE M., MESTDAGH M., PALIN W. M., GALLEZ B., LELOUP G. Irradiation mode's impact on radical entrapment in photoactive resins. Journal of Dental Research. 2010, v. 89, pp.1494-1498.

DOI: 10.1177/0022034510384624

[13] ELLIOTT, J. E., LOVELL L. G., BOWMAN C. N. Primary cyclization in the polymerization of bis-GMA and TEGDMA: a modeling approach to understanding the cure of dental resins. Dental Materials. 2001, v. 17, pp.221-229.

DOI: 10.1016/s0109-5641(00)00075-0

[14] PFEIFER, C. S., SHELTON Z. R., BRAGA R. R., WINDMOLLER D., MACHADO J. C., STANSBURY J. W. Characterization of dimethacrylate polymeric networks: a study of the cross-linked structure formed by monomers used in dental composites. European Polymer Journal. 2011, v. 47, pp.162-170.

DOI: 10.1016/j.eurpolymj.2010.11.007

[15] DUŠEK, K. Special features of network formation by chain crosslinking copolymerization. Collection of Czechoslovak Chemical Communications. 1993, v. 58, pp.2245-2265.

DOI: 10.1135/cccc19932245

[16] BARSZCZEWSKA-RYBAREK, I. M. Structure-property relationships in dimethacrylate networks based on Bis-GMA, UDMA and TEGDMA. Dental Materials. 2009, v. 25, pp.1082-1089.

DOI: 10.1016/j.dental.2009.01.106

[17] GUO, Z., E. BROWNE, J. COMPTON, H. SAUTEREAU, D. KRANBUEHL. Dielectric, dynamic mechanical and DSC evidence for a spatial and dynamic heterogeneity in a single phase polymer system. Journal of Non-Crystalline Solids. 2006, v. 352, pp.5025-5028.

DOI: 10.1016/j.jnoncrysol.2006.01.133

[18] KRZEMINSKI, M., MOLINARI M., TROYON M, COQUERET, X. Characterization by atomic force microscopy of the nano-heterogeneities produced by the radiation-induced crosslinking polymerization of aromatic diacrylates. Macromolecules. 2010, v. 43, pp.8121-8127.

DOI: 10.1021/ma101615k

[19] TESHIMA, W., NOMURA, Y., IKEDA A., KAWAHARA T., OKAZAKI M., NAHARA Y. Thermal degradation of photo-polymerized Bis-GMA/TEGDMA based dental resins. Polymer Degradation and Stability. 2004, v. 84, pp.167-172.

DOI: 10.1016/j.polymdegradstab.2003.10.007

[20] ACHILIAS, D. S., KARABELA M. M., SIDERIDOU I. D. Thermal degradation of light-cured dimethacrylate resins: Part I. Isoconversional kinetic analysis. Thermochimica Acta. 2008, v. 472, pp.74-83.

DOI: 10.1016/j.tca.2008.02.004

[21] Radiation curing: science and technology. 1st ed. New York: Springer Science Business Media, 1992, s. 57-133. Topics in applied chemistry. ISBN 978-1-4899-0714-1.

[22] KANNURPATTI, A. R., ANSETH J. W., BOWMAN C. N. A study of the evolution of mechanical properties and structural heterogeneity of polymer networks formed by photo-polymerizations of multifunctional (meth) acrylates. Polymer. 1998, v. 39, pp.2507-2513.

DOI: 10.1016/s0032-3861(97)00585-5

[23] COOK, W. D., FORSYTHE J. S., IRAWATI N., SCOTT T. F., XIA W. Z. Cure kinetics and thermo-mechanical properties of thermally stable photo-polymerized dimethacrylates. Journal of Applied Polymer Science. 2003, v. 90, pp.3753-3766.

DOI: 10.1002/app.12995

[24] MESQUITA, R. V., J. G. GERSTORFER. Influence of temperature on the viscoelastic properties of direct and indirect dental composite resins. Dental Materials. 2008, v. 24, pp.623-632.

DOI: 10.1016/j.dental.2007.06.025