**Preface to "Polymers Synthesis and Characterization"**

Polymer science represents a domain of great interest due to the possible applications of polymers in areas that range from the most common to those that are high-tech. To achieve this, synthesis and characterization techniques, as well as the correlation of the chemical structure and morphology with their properties, is critical. From the perspective of synthesis, there are two strategies for obtaining polymers: step-growth (polyaddition, polycondensation, and reversible-deactivation radical polymerization) and chain polymerization (radical polymerization, coordinative polymerization, and cationic and anionic polymerization). Polymer analogous reactions aimed at the control of the hydrophilic/hydrophobic characteristics of the surface or the introduction of responsive moieties onto a polymer backbone are also interesting related topics. Surface modification can also be performed using surface-initiated controlled radical polymerization reactions such as atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT), nitroxide-mediated living free-radical polymerization (NMP), and iodine transfer polymerization (ITP). Through these methods, polymer grafts and block copolymers are obtained, displaying different properties than random or alternate polymers obtained by radical copolymerization, which follows the well-known Mayo–Lewis equation. Thus, the physical properties of the polymers can be tailored depending on the structures that are synthesized and their morphology. The right design that encompasses structure, composition, and morphology is the key to the final applications of polymeric structures.

The advancement of polymer applications continues to lead to the expansion of the synthesis and characterization techniques that can be facilitated by novel, smart, multifunctional polymers. There is a correlation between structure, composition, morphology, and properties of applications that leads to substantial benefits for specific applications.

This Special Issue established a collection of articles and reviews that follow the latest developments in polymer synthesis, their characterization techniques, and the correlation between structure and properties.

> **Edina Rusen** *Editor*
