The thermal degradation and the flame retardancy of ABS and PC/ABS alloy were studied. Few studies on the flame retardancy of polymer alloy have been reported although polymer alloy is widely used for its excellent perfomance. In this study, the flame retardancy was analyzed through their thermal degradation and other measurement. A halogenated compound was effective for ABS because the major scission product was styrene, generated from the polystyrene(PS)matrix in ABS. On the other hand, some phosphorous compounds and metal‐organic complexes gave excellent results for the PC/ABS alloy. The total heat fluxes were restrained by adding these compounds and complexes, and a carbonaceous layer was observed on the surface after burning. TCP/Fe(acac)₃ was the most effective in restraining burning and the fire extinguished after 10s for PC/ABS. The flame retardancy of polymeric alloy was determined by two causes:one was the contribution of the major scission compounds that accelerate burning, and the other was the effect of the carbonaceous layer on the polymer surface. Therefore, to achieve effective flame retardancy, the generation of the maior scission compounds should be restrained and further a catalyst by which one of the polymers changes into a carbonic compound must be added.

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Silicone rubber is widely used as tubes in beverage circuit because of its merit of high heat-resistance and food hygiene. The organic peroxide cured silicon rubber has been used for this purpose, however, it has being replaced by the platinum cured rubber in recent years. The vulcanization promoted by organic peroxides inevitably generates debris. The remained debris is necessary to be removed by postcure treatment of 225 ^oC, 24hrs, which is rather harsh condition for silicone rubber. The vulcanization by platinum catalysts generates no such debris, and hence has been recognized as a promising method to ensure the quality of beverages. However, the relationship between physical properties, in particular, heat resistance capacity and postcure condition was not examined. The present report compares the silicone rubbers prepared by peroxide and platinum vulcanization, with employing various postcure conditions, in physical properties of tensile strength, ultimate elongation, and hardness before and after the themal aging process. Advantage of the platinum cured rubber was evident under the postcure conditions that were settled to ensure their tasteless nature. Moreover, thermal deterioration of the platinum cured rubber was remarkably suppressed using a heat resistance reagent containing several kinds of rare earth metals.

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Kenaf bast fiber was used to prepare kenaf fiber/linear low-density polyethylene (LLDPE) composite by injection molding technique. Degradation of LLDPE during the processing was investigated using FT-IR analysis. It was observed that slight degradation of pure LLDPE took place after injection molding. It was also found that the extent of degradation of LLDPE became higher when kenaf fiber was used as the filler for LLDPE composite. The addition of kenaf fiber would cause higher shear stress on LLDPE during processing, resulting in higher extent degradation of LLDPE.

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