本研究は, 熱分解やその他の測定の解析を通じてABS, PC/ABSの 難燃性について検討を行った. その結果, ABSで はハロゲン系難燃剤が有効であった. これは主要な分解生成物がスチレンであり, ABS中のポリスチレンのマトリックスが分解して生じたことにより, ポリスチレンに有効な難燃剤が良い結果をもたらしたためである. 一方, PC/ABSで はリン系と金属-有機錯体が優れた結果を与えた. リン化合物と錯体を添加することによって燃焼時の総発熱量も少なくなったが, これは燃焼時に表面に炭化層が形成されたことによる. たとえばPC/ABSでは, TCP/Fe(acac)₃が もっとも良い結果を与え, 約10秒で消炎した. ポリマーアロイの燃焼性は二つの要因が支配する. 第一に燃焼を促進する主要な分解生成物の寄与が大きいこと, 第二に高分子表面の炭化層が抑制する効果である. 従って, 主要な分解生成物の発生を抑制すること, アロイの中に含まれる炭化層を形成する成分を炭化させる触媒を加えることが燃焼を抑制するのに重要である.

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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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