we develop and study a mathematical model which describes how an inert species contained in the initial monomer/initiator mixture is redistributed by a propagating polymerization front. This study is relevant to the production of polymers for optical applications. @ 2002 Elsevier Science Ltd. All rights reserved. Keywords--Free radical polymerization, Frontal polymerization, Mathematical modeli...

The aim of this research was to produce a convenient additive for enhancing the properties, especially the fluid loss, of oil well cement slurries. In this regard, a variety of drilling/cementing chemical additives known as fluid loss controllers were prepared through derivatization and chemical modification of lignite. Lignite-based graft copolymers were synthesized using different groups of a...

Free radical polymerization of ethylene in an intermediate pressure and temperature range (P(ethylene) < 250 bar and 50 °C < T < 90 °C) in the presence of an organic solvent has been studied. Under selected conditions (P, T) and according to the amount of organic solvent added, either a supercritical monophasic or a biphasic medium is obtained. In the case of a biphasic medium, polymerization o...

Self-healing chemistry used for damage repair have not previously been demonstrated for free-radical polymerization pathways. However, this chemistry is important for addition polymers such as poly(methyl methacrylate) used in bone cement and epoxy vinyl ester used in dental resins. Self-healing biomaterials offer the potential for safer and longer lasting implants and restoratives by slowing o...

antioxidants are vital substances which possess the ability to protect the body from damage caused by free radical induced oxidative stress. a variety of free radical scavenging antioxidants exist within the body which many of them are derived from dietary sources like fruits, vegetables and teas. in this study the antioxidant activity and radical scavenging activity of methanolic extracts of s...