Sonalee Das

Study of UV aging on the performance characteristics of vegetable oil and palm oil derived isocyanate based polyurethane

The impact of UV aging on the characteristic properties of synthesized polyurethane (PUs) from castor oil and transesterified castor oil with palm oil based isocyanate and 1,4 butanediol was investigated at different exposure time of 0, 250, 500, 750 and 1,000 h, respectively. The aging properties of the PU films were analyzed through differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Tensile tests. The PU films derived from castor oil showed noticeable changes in chemical structure after 250 h of UV exposure owing to chain scission of the urethane group. A considerable decrease in the thermal and tensile properties of the developed PU films was observed due to the plasticization phenomenon. SEM micrographs revealed morphological changes through the appearance of cracks and blisters composed of primary amines on the surface of exposed PU films. However, PUs derived from transesterified castor oil with a higher hydroxyl value exhibited improved UV resistance characteristics due to higher crosslinking and degrade only after 750 h of exposure. Thus, the synthesized green PUs based on transesterified castor oil with palm oil based isocyanate compositions can be candidate materials for developing UV resistant coating material.

Insight on Castor Oil Based Polyurethane and Nanocomposites: Recent Trends and Development

ABSTRACT Castor oil has gained momentous attention as a valuable bio-based monomer and a potential alternative to the current petrobased polyol for synthesizing polyurethane due to the presence of inherent hydroxyl group. In spite of its huge potentiality very little has been reviewed regarding the development of polyurethane from castor oil. This review thus highlights the recent trends and development in the field of polyurethane and its nanocomposite based on castor oil including its biodegradability and weatherability studies. Further, this review also provides an insight regarding the utilization of castor oil based polyurethane and its nanocomposite for coating application. GRAPHICAL ABSTRACT

Crystallization of Polymer Blend Nanocomposites

Abstract The concept of reinforcing nanofiller into multicomponent polymer blend has been successfully developed for commercial aspects. The addition of a nanofiller to the polymeric blend resulted in lightweight, stronger, and cheaper structures, which are the main goals of recent materials science and engineering applications. The crystallization behavior of the polymer blends was significantly affected by the compatibilization action and nucleation effect delivered by the nanofiller reinforcement. Nanoparticles can either increase or decrease the crystallization rate of a semicrystalline polymer. Besides the influence on nucleation, a retarding effect of nanofiller on the crystal growth of polymer matrices has been a point of consideration. This chapter highlights several types of polymeric blends in combination with various nanofillers.