Book excerpt: Low-Density Polyethylene: Properties and Applications examines the rheology of low-density Pply(ethylene)-based systems. Processing this commodity, alone or in combination with different micro/nano-fillers, requires a deep knowledge of its rheological behavior in order to set up the process parameters. Following this, the comprehensive research progress on low-density polyethylene is reviewed, and the mechanisms of low-density polyethylene biodegradation are summarized. Additionally, the effect of microorganisms on low-density polyethylene and products of this degradation with their level of toxicity is discussed. Later, the authors focus on the different types of low-density polyethylene, microorganism-mediated degradation, changes in the physiological properties of low-density polyethylene post degradation and its applications in other fields. The detailed knowledge of preferential sorption is studied in an effort to reveal new information regarding low-density polyethylene properties. Consequently, the usage of low-density polyethylene in membrane separations is promoted.