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A series of biodegradable thermo‐sensitive hydrogels were synthesized by ring‐opening polymerization of methoxy‐poly(ethylene glycol) (mPEG) and various ester monomers, i.e. D,L‐lactide, glycolide, β‐propiolactone, δ‐valerolactone and ε‐caprolactone. The copolymers were characterized using 1H NMR spectroscopy and gel permeation chromatography. The micelle properties were also measured. The results indicated that the diblock copolymers formed nano‐micelles at low concentrations in aqueous phase. The lower critical solution temperatures of the diblock copolymers were above 35 °C at 1 wt%. As the temperature increased above room temperature, the diblock copolymer solutions underwent a sol‐to‐gel phase transition, which was manifested in viscosity increases, indicative of the formation of a gel. The mPEG–polyester diblock copolymer solutions exhibited sol‐gel transition behavior as a function of temperature and polymer concentration. Copyright © 2010 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The article presents a study on the use of heterogenous catalytic process for biodiesel synthesis. Using a heterogenous catalyst made from cation-exchange resin, the authors produced biodiesel synthesis via fatty acids esterification with methanol. They studied the kinetics of esterification at the different levels of catalyst loading, reaction temperature and molar ratio of methanol to fatty acids. A pseudo-homogenous kinetic model coupling the effect of catalyst loading, reaction temperature and methanol/fatty acids molar ratio was used to predict the optimal operating condition for obtaining equilibrium conversion of 0.99.