Effects of water temperature on degradation of several biodegradable polymers immersed in water

Four kinds of biodegradable polymers were immersed in water around 301 K and 351 K for fixed periods from 1 to 720 hours, and their degradation was studied by observing their shapes, weights, molecular weights, and space charge distributions. Samples tested were poly-L-lactic acid (PLLA), polycaprolactone butylene succinate (PCL-BS), polyethylene terephthalate succinate (PETS), and polybutylene succinate (PBS). From space charge observation, it is assumed that water accelerates ionization of substances and extraction of ionizable species. The durability against water becomes much worse when the water is 351 K compared to 301 K for all the samples. For example, PLLA crumbles easily at 351 K, while it shows good durability at 301 K.