Polymers without Petrochemicals: Sustainable Routes to Conventional Monomers.

Access to a wide range of plastic materials has been rationalized by the increased demand from growing populations and the development of high-throughput production systems. Plastic materials at low costs with reliable properties have been utilized in many everyday products. Multibillion-dollar companies are established around these plastic materials, and each polymer takes years to optimize, secure intellectual property, comply with the regulatory bodies such as the Registration, Evaluation, Authorisation and Restriction of Chemicals and the Environmental Protection Agency and develop consumer confidence. Therefore, developing a fully sustainable new plastic material with even a slightly different chemical structure is a costly and long process. Hence, the production of the common plastic materials with exactly the same chemical structures that does not require any new registration processes better reflects the reality of how to address the critical future of sustainable plastics. In this review, we have highlighted the very recent examples on the synthesis of common monomers using chemicals from sustainable feedstocks that can be used as a like-for-like substitute to prepare conventional petrochemical-free thermoplastics.

Hierarchy of Complex Glycomacromolecules: From Controlled Topologies to Biomedical Applications.

Carbohydrates bearing a distinct complexity use a special code (Glycocode) to communicate with carbohydrate-binding proteins at a high precision to manipulate biological activities in complex biological environments. The level of complexity in carbohydrate-containing macromolecules controls the amount and specificity of information that can be stored in biomacromolecules. Therefore, a better understanding of the glycocode is crucial to open new areas of biomedical applications by controlling or manipulating the interaction between immune cells and pathogens in terms of trafficking and signaling, which would become a powerful tool to prevent infectious diseases. Even though a certain level of progress has been achieved over the past decade, synthetic glycomacromolecules are still lagging far behind naturally existing glycans in terms of complexity and precision because of insufficient and inefficient synthetic techniques. Currently, specific targeting at a cellular level using synthetic glycomacromolecules is still challenging. It is obvious that multidisciplinary collaborations are essential between different specialized disciplines to enhance the carbohydrate receptor-targeting paradigm for new biomedical applications. In this Perspective, recent developments in the synthesis of sophisticated glycomacromolecules are highlighted, and their biological and biomedical applications are also discussed in detail.

Fluorinated Polymers via Para-Fluoro-Thiol and Thiol-Bromo Click Step Growth Polymerization.

Click reactions are utilized widely to modify chain ends and side groups of polymers while click polymerizations based on step-growth polymerization of bifunctional monomers have recently attracted increased attention of polymer chemists. Herein, the combination of two highly efficient click reactions, namely para-fluoro-thiol click and thiol-bromo substitution reactions, is demonstrated to form fluorinated polymers with tuned hydrophobicity owing to the nature of the dithiol linker compound. The key compound in this study is 2,3,4,5,6-pentafluoro benzyl bromide that provides the combination of thiol click reactions. The thiols used here are 4,4-thiobisbenzenthiol, 2,2'-(ethylenedioxy) diethanethiol, and 1,2-ethanedithiol that allow tuning of the properties of obtained polymers. The step-growth click reaction conditions are optimized by screening the effect of reaction temperature, base, solvent, and stochiometric ratio of the compounds. Thermal properties and hydrophobicity of synthesized polymers are determined via water contact angle, thermogravimetric analysis and differential scanning calorimetry measurements, showing thermal stability up to 300 °C, glass transition temperatures ranging from -25 to 82 °C and water contact angles ranging from 55 to 90 °C.