In this study, the bio-based epoxy nanocomposites were prepared from acrylated epoxidized castor oil toughened diglycidyl ether of bisphenol A epoxy network filled with sisal fibers and cloisite 30B clay. The chemical structure of acrylated epoxidized castor oil resin was confirmed by Fourier transform infrared and Proton nuclear magnetic resonance (1HNMR) spectroscope techniques. Mechanical and thermal properties of the sisal fiber reinforced acrylated epoxidized castor oil toughened diglycidyl ether of bisphenol A epoxy composites and nanocomposites were investigated. Mechanical tests revealed that bio-based epoxy nanocomposites (containing 80% diglycidyl ether of bisphenol A/20% acrylated epoxidized castor oil / 30% treated sisal fiber/ 1% cloisite 30B weight ratio) were found to be higher in tensile strentgh to 78%, flexural strentgh to 44% and impact strength to 20% than the 80% diglycidyl ether of bisphenol A/20% acrylated epoxidized castor oil matrix. Thermogravimetric analysis results showed that the thermal stability of diglycidyl ether of bisphenol A /acrylated epoxidized castor oil matrix increased with the incorporation of alkali-silane-treated sisal fiber and cloisite 30B nanoclay. The apparent activation energy was increased from 236 to 273 KJ/mol with the addition of 1% cloisite 30B clay and 30% alkali-silane-treated sisal fiber to the 80% diglycidyl ether of bisphenol A /20% acrylated epoxidized castor oil matrix. Scanning electron microscopy was performed to investigate the fracture behaviour at the fiber-matrix interface.

We report the in-situ synthesis of poly(lactic acid)–halloysite nanotubes (PLA-HNT) bionanocomposites, with a perspective to improve the interaction between PLA and HNT. Three PLA-HNT bionanocomposites with different HNT weight percentages were synthesized by polycondensation, followed by azeotropic distillation technique. Fourier transform infrared spectroscopy studies indicated the existence of hydrogen bonding between terminal hydroxyl groups of PLA and Si–O–Si groups present in the outer surface of HNT. Wide-angle X-ray diffraction, 29Si- and 27Al-nuclear magnetic resonance spectroscopy analysis confirmed the intercalation of PLA into HNT. Scanning electron microscopy analysis confirmed that there was no significant agglomeration and PLA matrix was found to be embedded with HNT. Transmission electron microscopy analysis also gave ample proof to substantiate the intercalation of PLA chains into HNT. Studies on zeta potential of PLA-HNT bionanocomposites, as compared with PLA, also confirmed the interactions between PLA and HNT. Single melting peak in differential scanning calorimetry analysis indicated the existence of one form of crystalline structure.

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