Parametric Studies on the Grafting of Poly(Methyl Methacrylate) onto Organophilic Montmorillonite Using Silylated Clay Platelets |
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| Authors: | Mahmood Torabi Angaji Reza Rafiee Mahmood Hemmati Mahdi Abdollahi Mir Karim Razavi Aghjeh |
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| Institution: | 1. Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran;2. Division of Polymer Science and Technology, Research Institute of Petroleum Industry (RIPI), Tehran, Iran;3. Division of Polymer Science and Technology, Research Institute of Petroleum Industry (RIPI), Tehran, Iran;4. Polymer Engineering Department, Faculty of Chemical Engineering, Tarbiat Modares University, Tehran, Iran;5. Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran |
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| Abstract: | Poly(methyl methacrylate) (PMMA)/organophilic montmorillonite (Cloisite 30B) nanocomposites were synthesized by the chemical grafting of PMMA onto Cloisite 30B via solution polymerization of methyl methacrylate (MMA) with vinyl-modified organoclay. The effects of different parameters such as clay weight percent (CWP), solvent per monomer volume ratio, and dispersion time on the properties of the PMMA grafted Cloisite 30B were investigated using the Taguchi experimental design method. This method gives a much-reduced variance for the experiments with optimum setting of control parameters and provides a set of minimum experiments compared to the conventional methods. Qualitative evidence for the chemical grafting of the PMMA onto Cloisite 30B was confirmed by Fourier transform infrared spectroscopy (FT-IR). X-ray diffraction (XRD) was used to investigate interlayer changes of the clay in the grafted nanoplatelets. The exfoliated/intercalated morphology of the nanocomposites was confirmed by XRD. Furthermore, thermal properties were measured by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). Statistical analysis of results revealed that clay weight percent and solvent per monomer ratio had significant effects on the properties of final products. The percent of grafted PMMA and storage modulus of PMMA/30B nanocomposites decreased with increasing clay content due to better dispersion of the clay at lower loadings. On the other hand, because of a tendency to formation of homopolymer and oligomers at higher solvent loadings; the percent of grafted PMMA, storage modulus and glass transition temperature of PMMA/30B nanocomposites decreased with an increase in solvent per monomer volume ratio. However, the obtained PMMA/30B nanocomposites at the optimum conditions, was exhibited a higher glass transition temperature, higher storage modulus and better thermal stability than the pure PMMA. |
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| Keywords: | cloisite 30B nanocomposite poly(methyl methacrylate) silane coupling agent solution graft polymerization taguchi experimental design |
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