Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impact...Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impacts. The major adverse consequence of these additives in consumer products is in the form of endocrine-disruption related health-downgrades. Such findings still remain underappreciated in most parts globally;part of which could be ascribed to fragmented studies towards better understanding on the occurrence, release and migration, human exposure, epidemiology and risk assessment of PA from packaging materials. In addition there is limited and disconnected dissemination of research findings on PA effects and mitigation measures to society at present. In light of appropriateness of this topic, a trans-disciplinary research agenda is required for addressing exposure routes to PA, human health burden and prevention measures. This perspective article discusses important research questions relating to PA, which try to shed light to a grey scientific area and help increase consumers’ awareness and intervention to such exposures.展开更多
Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material.The moisture resident in the micro-cavities gives rise to the internal vapor pressure that d...Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material.The moisture resident in the micro-cavities gives rise to the internal vapor pressure that drives the thermal expansion of micro-cavities as temperature rises.The plastic packaging materials are considered a class of thermo-hyperelastic materials,thus allowing the micro-cavities to thermally expand to the substantial extent before the cracking failure.The micro-cavities can be moisture-abundant(i.e.,wet) or substantially dry when cracking occurs.Cracking appears to be almost certain in the presence of wet cavities.The possibility of cracking in dry cavities turns to be two-sided:when the initial volume fraction of the micro-cavities is relatively small,cracking cannot occur in the dry cavities regardless of the phase transition temperature;when the initial cavity volume fraction is relatively large,cracking tends to occur in the dry cavities especially when the phase transition temperature is large.Because of the two-sided cracking possibility,the dry-cavity cracking mode presents a scenario that might reveal the mechanism of popcorning-type cracking failure in plastic packaging materials.展开更多
文摘Plastic and polymer additives (PA) have unique rational advantages for various water and food packaging applications. However, their (bio)chemical natures are recently recognized for their negative human health impacts. The major adverse consequence of these additives in consumer products is in the form of endocrine-disruption related health-downgrades. Such findings still remain underappreciated in most parts globally;part of which could be ascribed to fragmented studies towards better understanding on the occurrence, release and migration, human exposure, epidemiology and risk assessment of PA from packaging materials. In addition there is limited and disconnected dissemination of research findings on PA effects and mitigation measures to society at present. In light of appropriateness of this topic, a trans-disciplinary research agenda is required for addressing exposure routes to PA, human health burden and prevention measures. This perspective article discusses important research questions relating to PA, which try to shed light to a grey scientific area and help increase consumers’ awareness and intervention to such exposures.
基金supported by the National Natural Science Foundation of China (Grant No. 11172195)the Natural Science Foundation of Shanxi Province,China (Grant No. 2012011019-4)
文摘Thermal cracking occurs in the plastic packaging materials due to the presence of moisturized micro-cavities in the material.The moisture resident in the micro-cavities gives rise to the internal vapor pressure that drives the thermal expansion of micro-cavities as temperature rises.The plastic packaging materials are considered a class of thermo-hyperelastic materials,thus allowing the micro-cavities to thermally expand to the substantial extent before the cracking failure.The micro-cavities can be moisture-abundant(i.e.,wet) or substantially dry when cracking occurs.Cracking appears to be almost certain in the presence of wet cavities.The possibility of cracking in dry cavities turns to be two-sided:when the initial volume fraction of the micro-cavities is relatively small,cracking cannot occur in the dry cavities regardless of the phase transition temperature;when the initial cavity volume fraction is relatively large,cracking tends to occur in the dry cavities especially when the phase transition temperature is large.Because of the two-sided cracking possibility,the dry-cavity cracking mode presents a scenario that might reveal the mechanism of popcorning-type cracking failure in plastic packaging materials.
