Synthesis and Characterization of Imide Containing Hybrid Epoxy Resin with Improved Mechanical and Thermal Properties

Phosphorous containing amine, tripropyldiamine phosphine oxide (TPDAP), and hybrid monomer 4-(N-phthalimidophenyl) glycidylether (PPGE) were synthesized and characterized by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and elemental analysis (EDX). PPGE was incorporated in bisphenol A epoxy resin (BPA) in various concentrations (5% to 20%), based on a weight percentage of BPA resin. Curing was carried out with the stoichiometric amount of TPDAP and 1,3-propanediamine (PDA) to result in cross-link network. Various mechanical, chemical, thermal, and flame retardant properties of modified and unmodified epoxy resin were studied. The coatings obtained with the addition of PPGE were found to have improved properties as compared with those of the unmodified resin. Coatings with 15% loading of PPGE showed improved flame retardant and mechanical properties with stable thermal behaviour

MODELING OF 3-PHASE SPARGED REACTOR - NON-UNIFORM SOLID CONCENTRATION PROFILE

Models have been developed in order to obtain the non-uniform concentration profiles and the exit age distribution of the solid phase in three-phase sparged reactors. The constant-size particles as well as the dissolving particles have been considered. Procedures have been developed for the estimation of solid-phase residence time even though the net particle velocity is in the backward direction. The effects of superficial liquid velocity, particle size and solid-phase dispersion coefficient on solid-phase residence time have been investigated. Using the exit age distribution and the conversion-time relationships for single particles, performance charts have been constructed for when the rate-controlling step is associated with the solid phase. Several reaction mechanisms have been considered for the construction of performance charts. It has been shown that the design of reactor outlet is very important and governs the solid-phase concentration profile within the reactor. An attempt has been made to propose a theoretical boundary condition at the reactor outlet for a non-uniform solid concentration profile of constant-size particles. The relationship between the design of the outlet and the concentration jump at the outlet has been analysed

Underutilization of bubble column reactors due to desorption

The occurrence of undesirable desorption of a gaseous reactant due to its supersaturation in the liquid phase is investigated for slow gas-liquid reactions in tall bubble columns within the framework of a modified axial dispersion model. The model accounts for axial dispersion in the gas and liquid phases and change in volume of the gas phase due to absorption of the gaseous reactant and prevailing static head of the liquid phase. For both cocurrent and countercurrent flow operations and for arbitrary kinetics, it is established analytically that such desorption occurs solely due to significant pressure variation in the reactor. Necessary and sufficient conditions for the restriction of such desorption to the top portion of the reactor are also obtained in the regions of interest for bubble column operation. Numerical illustrations are provided for two commonly encountered situations: (a) imperfectly mixed gas and liquid phases, and (b) an unmixed gas phase with a well-mixed liquid phase. The roles of various system parameters in the occurrence and elimination of desorption and the penalties imposed by it on reactor volume and power requirements for the desired gas phase and liquid phase conversions are examined

Modelling of three phase sparged catalytic reactors

This article does not have an abstract