Preparation of Siloxane-modified Tetraglycidyl Epoxy-Clay Nanocomposites - Its Thermal and Morphological Properties

Abstract

The organic—inorganic hybrid involving hydroxyl-terminated polydimethylsiloxane (HTPDMS)-modified epoxy, filled with organo-modified flurohectorite clay of various percentages (1—5 wt%) were prepared via in situ polymerization using γ-amino propyltriethoxysilane as cross-linking agent in the presence of dibutyltindilaurate catalyst. The reactions involved during the curing process between epoxy and siloxane were confirmed by FT-IR. The results of differential scanning calorimetry and dynamic mechanical analysis show that the glass transition temperatures of the clay-filled hybrid epoxy systems are lower than that of neat epoxy. The data obtained from the thermal studies indicated that improved thermal stability was due to the incorporation of nanoclay into siloxane-modified epoxy hybrid systems. The morphologies of the siloxane containing epoxy—clay hybrid systems show heterogeneous character, due to the partial incompatibility of HTPDMS. Scanning electron microscopy indicates the phase separation, induced by the polymerization, occurs in the HTPDMS-modified epoxy hybrids to yield spherical particles of siloxane-rich phase, which are uniformly dispersed in the continuous epoxy matrix. Microstructures of nanocomposites were ascertained from X-ray diffraction (XRD) and transmission electron microscopy. The formation of exfoliated structure of organoclay was confirmed from the XRD pattern and shows interlayer spacing between 3.42 and 8.50 Å. Hybrid epoxy nanocomposites containing higher percentage composition of organo-modified flurohectorite clay contents (up to 5 wt%) display more pronounced improvements in thermal properties and moisture resistance than corresponding unmodified epoxy matrices.

Development of ricehusk ash reinforced bismaleimide toughened epoxy nanocomposites

“…The present work involves the development of an organic and inorganic hybrid in combination with a recycling waste material (rice husk ash) to enhance the properties of organic polymer. The wide spread uses and properties of epoxy resin have been extensively studied by our research group for the past two decades (Dinakaran et al, 2003 ; Rajasekaran and Alagar, 2007 ; Premkumar et al, 2008 ; Ramesh et al, 2010 ; Selvaganapathi et al, 2010 ; Chandramohan and Alagar, 2011 ; Vengatesan et al, 2011 ; Kanimozhi et al, 2013 ; Prabunathan et al, 2013 ). In the present study an attempt has been made to form a covalent bond between organic polymers and inorganic components through coupling agent to enhance the compatibility of components involved (Farhadyar et al, 2005 ; Bagherzadeh and Mahdavi, 2007 ; Xinghong et al, 2007 ; Qingming et al, 2008 ; Balamurugan and Kannan, 2010 ; Sea-Fue et al, 2010 ).…”

Synthesis and characterization of 1, 1-bis (3-methyl-4-epoxyphenyl) cyclohexane-toughened DGEBA and TGDDM organo clay hybrid nanocomposites

“…Although modification with elastomers improved their impact characteristics, it leads to a decrease in physical properties such as hardness and rigidity, resistance towards solvents and glass transition temperature. [1][2][3][4][5][6][7][8][9] In order to maintain the balance of properties suitable for high performance applications, epoxy resins have been modified using materials having rigid and soft skeletons in our earlier studies and obtained hybrid epoxy materials with improved characteristics [10][11][12][13][14] according to the nature and the percentage incorporation of modifiers.…”

Preparation and Characterization of Organoclay Filled Polysulfone Nanocomposites

“…Octadecyl amine (ODA) (Aldrich) and dimethyl formamide (DMF) (SRL, Mumbai, India) were used as received without further purification. Fluorohectorite (FH) clay was modified with ODA to improve their dispersion and adhesion between clay and PSf matrix [15].…”