Eco-Friendly Production of Hyper-Cross-Linked Polymers Using Mechanosynthesis and Bioresources: A Critical Review

Abstract

Hyper-cross-linked polymers (HCPs) are receiving great attention due to their high specific surface areas, allowing them to offer high performances in many different applications. However, most of the time, their syntheses require hazardous and time-consuming protocols, making their implementation and scaling up difficult. To overcome this problem, a relatively old technology such as mechanosynthesis (MS) has gained renewed interest as a greener and faster technology to produce HCPs, which involves much lower energy consumption during the reaction process. In this perspective, the latest advances on the performances of HCPs based on MS protocols are compiled and analyzed, subdivided into those based on Friedel–Crafts alkylation, Scholl coupling reactions, and other less common procedures. An analysis of MS versus solvent-based protocols regarding the 12 principles of green chemistry is also reported, as well as a section including a summary of the most recent applications of HCPs. Finally, the use of biobased precursors for the formulation of HCPs is discussed, thus pooling knowledge for greener, faster, and more widely applicable future development of HCPs.

Green synthesis of hypercrosslinked polymers for CO2 capture and conversion: recent advances, opportunities, and challenges

“…A classical technique named mechanochemical synthesis 99 has become a more environmentally friendly and rapid method of synthesizing HCPs that consumes less energy during the reaction. 100 Lee et al 101 prepared HCPs using a simple ball milling method that avoids the use of toxic solvents containing chlorine (Fig. 8a and b).…”

Layered double hydroxides: where should research stress on for massive scaling up?

“…1 Comparison of co-precipitation and mechanosynthesis in view of the large-scale production of LDH powders, taking into account the basic principles of green chemistry. 29…”

“…1 Comparison of co-precipitation and mechanosynthesis in view of the large-scale production of LDH powders, taking into account the basic principles of green chemistry. 29 Another point in favour of the large-scale development of LDH is the availability of the salts or hydroxide precursors. This does not seem problematic regarding the chemical compositions considered in the different studies.…”

Synthesizing Hypercrosslinked Polymers with Deep Eutectic Solvents to Enhance CO2/N2 Selectivity

“…[3,7] A new research direction in HCPs is to improve the sustainability of HCP synthesis. Examples of such approaches include solvent-free mechanochemical synthesis, [8] thermal-induced polymerization of a tetrahedral monomer bearing four maleimide pendant groups without using any catalysts and initiators, [9] replacing metal halide Lewis acid catalysts with metal-free Brønsted acids, [10] or replacing the halogenated solvent with benign solvents such as sulfolane. [11] Sulfolane, an organosulfur solvent, which is commonly used in industrial chemical reactions, has demonstrated its feasibility in producing highly porous HCPs from biobased monomers.…”