Polymer blends and composites represent functional materials generated for combining useful properties of their components. Effective mixing of the components in these materials usually results in synergistic enhancements in mechanical, thermal, flow, barrier and flammability performances. This tuning and control on the material properties leads to the applications of these functional blends and composites in many applications. A great degree of advancements in these materials have been achieved in the recent years on all aspects related to material combinations, synthesis routes, organic-inorganic phase compatibilization methodologies, etc. This text aims to present a number of such blend and composite systems based on polyethylene (PE). For this reason, a majority of the chapters presented in this text focus on experimental details as well as accurate material characterizations to present deep insights into controlling structure- property correlations. For more details, please visit https: //centralwestpublishing.com