Degradable and Recyclable Polymers by Reversible Deactivation Radical Polymerization

Reversible deactivation radical polymerization(RDRP)provides unprecedented control over polymer composition,size,functionality,and topology.Various materials,such as linear polymers,star polymers,branched polymers,graft polymers,polymer networks,and hybrid materials,have been prepared by RDRP.The ability to control polymer topology also enabled precision synthesis of well-defined polymer topologies with degradable functional groups located at specific locations along a polymer chain.This review outlines progress in the synthesis of degradable polymers designed by RDRP,organized by topology and synthetic route.Recent progress in the depolymerization of polymers using RDRP mechanisms is highlighted and critically discussed.

Dispersity Regulation in Photo-controlled Radical Polymerization by Merging Aryl Sulfonyl Chloride Initiators and Mixed Disulfide Agents

On-demand regulation of molecular weight distribution(MWD)is crucial to influence the properties of polymers.In this work,we reported an organocatalyzed photo-controlled radical polymerization(photo-CRP)from the tosyl chloride initiator by combining two disulfides as chain transfer agents.This novel synthetic protocol allows facile access toward well-defined polymers with tunable MWDs and predetermined molecular weights.Experiments including structural characterization,kinetic investigation and chain-extension polymerization exhibited good chain-growth control for polymers of different dispersities.Given the easy accessibility of the initiating site(sulfonyl chloride)on many aromatic sources,this work presents a promising avenue to modify such substances with polymers of tailored MWDs,chain lengths and repeating units under metal-free and mild conditions driven by light.

Recent Advances of CuAAC Click Reaction in Building Cyclic Polymer

Cyclic polymers have attracted more and more attentions in recent years because of their unique topological structures and characteristic properties in both solution and bulk state. There are relatively few reports on cyclic polymers, partly because of the more demanding synthetic procedures. In recent years, 'click' reaction, especially Cu(I)-catalyzed azide-alkyne cycloaddition(CuAAC), has been widely utilized in the synthesis of cyclic polymer materials because of its high efficiency and low susceptibility to side reactions. In this review, we will focus on three aspects:(1) Constructions of monocyclic polymer using CuAAC 'click' chemistry;(2) Formation of complex cyclic polymer topologies through CuAAC reactions;(3) Using CuAAC 'click' reaction in the precise synthesis of molecularly defined macrocycles. We believe that the CuAAC click reaction is playing an important role in the design and synthesis of functional cyclic polymers.