ABS樹脂のフロン吸収挙動と環境応力破壊現象

抄録

It is generally known that crazing and/or cracking sometimes occurs on the surface of glassy polymers in contact with solvent. In this report, this environmental stress cracking (ESC) in ABS polymer-fron system was studied from the standpoint of sorption-diffusion kinetics. The absorption behavior of fron into ABS polymer was explained by CASE II transport followed by Fickian type diffusion in a short period. The absorption velocity, defined by the slope of weight gain curve in CASE II region, increased with the decrease of AN content, and a clear correlation between the absorption velocity and critical strain in solvent cracking test was observed. The creep test in liquid fron was also carried out to evaluate the resistance against fron. Under constant BR content, lower absorption velocity ABS polymer with higher AN content showed a better resistance. It was estimated that the lower absorption velocity of fron led to a better resistance against the cracking and creep. On the contrary, under constant AN content, higher absorption velocity ABS polymer with higher BR content showed a better creep resistance. This may be due to lower stress concentration in BR-rich ABS polymer.