The thermal oxidation of a film of isotactic polypropylene was studied using infrared spectroscopy. Reaction temperatures varied from 120"-150 "C. and oxygen concentrations from 7 -1 0 0~0 , by volume. A reaction scheme was postulated and kinetic expressions were developed therefrom. These expressions could explain very well the experimental results obtained. An activation energy of 31 f 1 kcal./mole was obtained for the initiation process whereas a value of 22 & 1 kcal./mole was obtained for the process involving the formation of non-volatile oxygenated substances. ZUSAMMENFASSUNG:Mit Hilfe der Infrarotspektroskopie wGrde die thermische Oxydation eines isotaktischen Polypropylenflms studiert. Die Reaktionstemperatur wurde von 120-150 "C variiert und die Q,-Konzentration von 7-100 Vol.-yo. Ein Reaktionsschema wurde aufgestellt, und daraus wurden kinetische Gleichungen abgeleitet. Diese Gleichungen standen in sehr guter Ubereinstimmung mit experimentellen Ergebnissen. Fur den InitiierungsprozeB wurde eine Aktivierungsenergie von 31 & 1 kcal/Mol gefunden, wahrend 22 ?c 1 kcal/Mol fiir die Reaktion angegeben wurden, in der die Bildung von nicht-fluchtigen Oxydationsprodukten erfolgte.

This is the first part of a survey of developments reported in the open literature during 1991 on the subject of injection molding of fiber-reinforced thermoplastics. Topics discussed include materials, polymers, reinforcing fibers and composite properties, advances in the injection molding process, fiber breakage, shrinkage, and warpage, as well as alternatives to the injection molding process.

This is part of a survey of recent developments in injection molding offiber reinforced thermoplastics. Topics discussed include materials and properties, the injection molding process with emphasis on fiber orientation and fiber length, advances in injection molding, as well as alternative methods for processing reinforced polymers.

This article is a review of developments published in the open literature during 1992 on subjects related to the injection molding of fiber reinforced thermoplastics. Topics discussed include high performance polymers, reinforcements, fiber-matrix adhesion, composite properties, data bases, factors involved in injection molding, product design, mold design and manufacture, product manufacture, and applications of fiber reinforced thermoplastic composites. The intent was to include information pertinent to improvements in the engineering, fabrication, and use of these materials.

This is the second part of a survey of recent developments in injection molding of fiber reinforced thermoplastics. Topics discussed include product design, mold design and fabrieaton, prototyping, product manufmture, and applications of these materials.