Preparation and Characterization of Bis-GMA/TEGDMA/Clay Nanocomposites at Low Filler Content Regimes

Abstract

Photo-curable polymer/clay nanocomposites have been prepared using Bis-GMA/TEGDMA (50/50 wt%) and modified as well as unmodified clays at different loading levels <10 wt%. The dispersion state of the clay layers has been studied using wide-angle X-ray diffraction and transmission electron microscopy as the key factor affecting the properties of the final cured nanocomposites. Photopolymerization induced volume shrinkage and double bond conversion percent was determined using density measurement techniques and Fourier transform infrared spectroscopy in order to verify the opacity of the clay filler on polymerization characteristics. Mechanical properties (flexural strength, flexural modulus, and diametral tensile strength) of the photo-cured nanocomposites were also evaluated according to standard test methods provided for materials with dental application. The results showed that the exfoliation or intercalation of the layers play to be the key factor on polymerization features and the mechanical properties of the final nanocomposites. The dispersion state is determined, first, to be dependent to the compatibilization level of the clay and secondly to its content in the composition. Experiments carried out by thermogravimetric analysis revealed also the thermal property dependence to relative abundance of exfoliated/intercalated layers.

Keywords

nanocomposites clay mechanical properties TGA photopolymerization.

Get full access to this article

View all access options for this article.

References

Giannelis, E.P. (1996). Polymer Layered Silicate Nanocomposites, Adv. Mater., 8: 29-35.

LeBaron, P.C. , Wang, Z. and Pinnavaia, T.J. (1999). Polymer-layered Silicate Nanocomposites: An Overview, Appl. Clay. Sci., 15: 11-29.

Alexandre, M. and Dubois, P. (2000). Polymer-Layered Silicate Nanocomposites: Preparation, Properties and Uses of New Class of Materials, Mater. Sci. Eng. Rep., 28: 1-63.

Vaia, R.A. and Giannelis, E.P. ( 2001). Polymer Nanocomposites: Statues and Opportunities , MRS. Bull., 26: 394-401.

Schmidt, D. , Shah, D. and Giannelis, E.P. ( 2002). New Advances in Polymer/Layered Silicate Nanocomposites, Curr. Opin. Solid State Mater. Sci. , 6: 205-212.

Ray, S.S. and Okamoto, M. (2003). Polymer/Layered Silicate Nanocomposites: A Review from Preparation to Processing, Prog. Polym. Sci., 28: 1539-1641.

Fukushima, Y. and Inagaki, S. (1987). Synthesis of an Intercalated Compound of Montmorillonite and 6-polyamide, J. Inclusion Phenom., 5: 473-482.

Carpio-Morales, A.J. , Olivares-Navarrete, R. , Estrada, M. and Arzate, H. ( 2004). The IADR/ AADR/CADR 82nd General Session, March 10-13, Honolulu, HI, USA.

Ekworapoj, P. , Magaraphan, R. and Martin, D.C. ( 2003). The 32nd Annual Meeting and Exhibition of the AADR March 12-15, San Antonio, TX, USA.

10.

Smucker, L.M. , Islam, K.M. and Pinnavaia , T.J. (2002). The IADR/AADR/CADR 80th General Session, March 6-9.

11.

Bowen, R.L. (1962). Dental Filling Material Comprising Vinyl-silane Treated Fused Silica and a Binder Consisting of the Reaction Product of Bis-phenol and Glycidyl Acrylate. US Patent No. 3,066,112.

12.

Paula, D.R. and Robesonb, L.M. (2008). Polymer Nanotechnology: Nanocomposites, Polymer, 49: 3187-3204.

13.

Gao, F. , Tong, Y. , Schricker , S.R. and Culbertson , B.M. (2001). Evaluation of Neat Resins on Methacrylates Modified with Methacryl-POSS, as Potential Organic-inorganic Hybrids for Formulating Dental Restoratives, Polym . Adv. Technol., 12: 355-360.

14.

Atai, M. , Watts, D.C. and Atai, Z. ( 2005). Shrinkage Strain-rates of Dental Resin-Monomer and Composite Systems, Biomaterials, 26: 5015-5020.

15.

Ge, J. , Trujillo, M. and Stansbury, J.W. ( 2005). Synthesis and Photopolymerization of Low Shrinkage Methacrylate Monomers Containing Bulky Substituent Groups, Dent. Mater. , 21: 1163-1169.

16.

Khatri, C.A. , Stansbury, J.W. , Schultheisz, C.R. and Antonucci , J.M. ( 2003). Synthesis, Characterization and Evaluation of Urethane Derivatives of Bis-GMA, Dent. Mater., 19: 584-588.

17.

Chena, M.H. , Chenc, C.R. , Hsu , S.H. , Sunc, S.P. and Suc , W.F. (2006). Low Shrinkage Light Curable Nanocomposite for Dental Restorative Material, Dent. Mater., 22: 138-145.

18.

Morgan, A.B. and Gilman, J.W. (2003). Characterization of Polymer-layered Silicate (Clay) Nanocomposites by Transmission Electron Microscopy and X-ray Diffraction: A Comparative Study, J. Appl. Polym. Sci., 87: 1329-1338.

19.

Mai, Y.W. and Yu, Z.Z. (eds) (2006). Polymer Nanocomposites, Woodhead Publishing Limited and CRC Press LLC, FL, USA.

20.

Deenadayalan, E. , Vidhate, S.H. and Lele, A. (2006). Nanocomposites of Polypropylene Impact Copolymer and Organoclays: Role of Compatibilizers, Polym. Int., 55: 1270-1276.

21.

Qiao, Y. , Chakravarthula, S.S. and Deliwala, J.K. ( 2005). Flexural Strength of Polyamide 6 Intercalated/Exfoliated Cements, Mater. Sci. Eng. A, 404: 270-273.

22.

Yu, M.F. , Lourie, O. , Dyer , M.J. , Moloni, K. , Kelley, T.F. and Ruoff, R.S. (2000). Strength and Breaking Mechanism of Multiwalled Carbon Nanotubes under Tensile Load, Science, 287: 637-640.

23.

Bhushan, B. (ed.) (2004 ). Introduction to Carbon Nanotubes, Springer Handbook of Nanotechnology, Part A, p. 67, Springer-Verlag, Berlin-Heidelberg.

24.

Leszczynska, A. , Pielichowski, K. , Njuguna , J. and Banerjee, J.R. (2007). Polymer/ Montmorillonite Nanocomposites with Improved Thermal Properties. Part I. Factors Influencing Thermal Stability and Mechanisims of Thermal Stability, Thermochim. Acta, 453: 75-96.

25.

Leszczynska, A. , Njuguna, J. , Pielichowski , K. and Banerjee, J.R. (2007). Polymer/ Montmorillonite Nanocomposites with Improved Thermal Properties. Part II. Thermal Stability of Montmorillonite Nanocomposites Based on Different Polymeric Matrixes, Thermochim . Acta, 454: 1-22.

26.

Jancar, J. , Wang, W. and Dibenedetto, A.T. ( 2000). On the Heterogeneous Structure of Thermally Cured Bis-GMA/TEGDMA Resins, J. Mater. Sci. Mater. Med., 11: 675-682.