ABSTRACT:The flame retardancy of polybutylene terephthalate (PBT) was studied focusing on the effect of various oxides. Thermo-gravimetric analysis, pyrolysis/ gas chromatography/mass spectrometry, and elemental analysis (EA) were used to analyze the flame retardancy, which were observed through the UL-test and a cone calorimeter. Many oxides influenced the flame retardancy and some of them could suppress the flammability of PBT. In particular, the blended-PBTs with ZnO and V 2 O 5 accelerated the degradation and the edges of oxygen consumption were shorter than neat-PBT although the flammability became poorer. The quantitative analysis of the scission products and the results of EA showed that hydrolysis, successive dehydration, and other various reactions changed the scission route to generate less flammable products.

No abstract

The contribution of the shape and size of polymers towards ignition for four kinds of polymers, PP (polypropylene), HIPS (rubber reinforced polystyrene), ABS (acrilonitril-butadiene-styrene copolymer) and PC (bisphenor-A type polycarbonate) was studied. The critical heat flux (CHF), which means that the specimen ignites after infinite time, depended on the shape and kind of polymer at the plane position heating. But it was not affected by these conditions at the side position heating. The CHF and other phenomena of ignition were analyzed and the two regions in one of which the shape and the kind of polymer affects them and in another region they was not affected. It will be useful to design electrical parts that reduce fire risks.

No abstract

ABSTRACT:The thermal behaviors and the flame-retardancy of styrene-ethylene-butadiene-styrene-block copolymer containing various additives were studied. The combustion was measured by the Underwriter laboratory (UL) test and cone calorimeter test and thermogravimetric analysis and program-mass spectroscopy were applied to analyze the thermal behaviors. The blend with halogen additives showed the best result in the UL test. However, the blend with red-phosphorous was the best in the cone calorimeter test. As the styrene sequence in the copolymer tended to degradate at a lower temperature, the major scission products spouted out from the polymer surface originated from polystyrene. The shorter the ignition times of the blends with red-phosphorous were, the lower the peak heat release rates were. It was an interesting phenomenon because it suggested that the chemical structure of the residue changed to more stable polymers.