Effect of irradiation on the degradability of polypropylene in the natural environment

Crystalline structure of polypropylene in blends with thermoplastic elastomers after electron beam irradiation

“…Such a sudden viscosity diminution is an evidence of the PP chain cracking during irradiation without formation of cross-linked structures and gel creation. This phenomenon is also reported in the literature (Yoshii et al, 1995).…”

“…This dose is slightly larger than that recommended for medical equipment sterilization, which should not change the crystalline structure of PP. According to literature data (Yoshii et al, 1995;Ż uchowska, 1988;Ż uchowska et al, 2003) macroradicals in irradiated PP have a long life time reaching a few months. Hence, the degradation and/or crosslinking proceeds even if the radiation action has finished.…”

Improved thermal oxidation stability of polypropylene films in the presence of β-nucleating agent

“…To date, the effect of β-NA on the oxidation stability of PP has attracted increasing attention under ultraviolet exposure or γ-radiations. Yoshii et al [22] found that the radiation stability of PP with β-NA became worse than that without β-NA, which was attributed to the higher proportion of crystal boundaries present in the nucleated PP. Obadal et al [23,24] suggested that higher UV-light scattering and absorbance of β-PP was responsible for its higher oxidative stability compared to the neat PP.…”

Effects of environmental aging in polypropylene obtained by injection molding

“…[10][11]. Previous studies have shown that in the case of PP irradiated at 30 kGy, and exposed to the environment, showed that the tensile strength decreases with time during the 60 days of exposure period, so that the study showed PP exposed to environmental degradation is accelerated by irradiation [12]. Another study conducted by Komatsu et.al showed that polypropylene with clay and irradiated at 12.5 kGy, when exposed to environmental aging for 12 months, showed large cracks and fissures [13].…”