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Precise sequence‐defined polymers (SDPs) with uniform chain‐to‐chain structure including chain length, unit sequence, and end functionalities represent the pinnacle of sophistication in the realm of polymer science. For example, the absolute control over the unit sequence of SDPs allows for the bottom‐up design of polymers with hierarchical microstructures and functions. Accompanied with the development of synthetic techniques towards precision SDPs, the decoding of SDP sequences and construction of advanced functions irreplaceable by other synthetic materials is of central importance. In this Minireview, we focus on recent advances in SDP sequencing techniques including tandem mass spectrometry (MS), chemically assisted primary MS, as well as other non‐destructive sequencing methods such as nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD), and nanopore sequencing. Additionally, we delve into the promising prospects of SDP functions in the area of cutting‐edge biological research. Topics of exploration include gene delivery systems, the development of hybrid materials combining SDPs and nucleic acids, protein recognition and regulation, as well as the interplay between chirality and biological functions. A brief outlook towards the future directions of SDPs is also presented. [ABSTRACT FROM AUTHOR]

Precise sequence‐defined polymers (SDPs) with uniform chain‐to‐chain structure including chain length, unit sequence, and end functionalities represent the pinnacle of sophistication in the realm of polymer science. For example, the absolute control over the unit sequence of SDPs allows for the bottom‐up design of polymers with hierarchical microstructures and functions. Accompanied with the development of synthetic techniques towards precision SDPs, the decoding of SDP sequences and construction of advanced functions irreplaceable by other synthetic materials is of central importance. In this Minireview, we focus on recent advances in SDP sequencing techniques including tandem mass spectrometry (MS), chemically assisted primary MS, as well as other non‐destructive sequencing methods such as nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD), and nanopore sequencing. Additionally, we delve into the promising prospects of SDP functions in the area of cutting‐edge biological research. Topics of exploration include gene delivery systems, the development of hybrid materials combining SDPs and nucleic acids, protein recognition and regulation, as well as the interplay between chirality and biological functions. A brief outlook towards the future directions of SDPs is also presented. [ABSTRACT FROM AUTHOR]

From 2,5-furan dicarboxylic acid, a robust biomass platform molecule, furan-based porous polyamide ( FPPA-1 and -2 ) was synthesized and applied for the removal of Hg2+ from water. FPPA-1 and -2 were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The effects of pH, dosage, contact time, temperature and concentration on the adsorption of Hg2+ were systematically investigated. The pseudo-second-order kinetics and the Langmuir isotherm model are in the best agreement with the experimental data, and the maximum adsorption capacity is 462 mg g−1. Thermodynamically, the adsorption of Hg2+ is a spontaneous adsorption process. There was no significant loss of performance during five regeneration cycles. In combination with the experimental data and density functional theory (DFT) calculation, the chelation mechanism of Hg2+ was demonstrated. Our study offers new perspectives for the removal of Hg2+ from wastewater. [Display omitted] • Furan-based porous polyamides were successfully prepared and removed Hg2+ from water. • The highest adsorption capacity of furan-based porous polyamide for Hg2+ was 462 mg g-1. • Hg2+ adsorption mechanism was proposed by spectral technique and DFT calculations. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Polymer mechanochemistry on reactive species has attracted more and more attentions over the past 20 years, as the mechanochemical generation of reactive species has a great potential in developing different polymeric materials for various purposes, such as stress detection, self‐healing, self‐strengthening, controllable degradation and release of small molecules. In this review, we first discuss the recent progress on polymer mechanochemistry of the reactive species that are generated from the mechanochemical reactions of mechanophores. Five types of reactive species, including radical, zwitterion, ionic, carbene and neutral intermediates, and their applications were reviewed in detail. Since mechanochemical reactions are sensitive to the mechanophore structure and polymer framework, we then discuss how mechanophore isomerism, polymer structure, polymer attachment point, and polymer architecture influence the mechanophore activation. At last, we provide our perspectives on the polymer mechanochemistry of reactive species. Key Scientists: In the 1930s, a seminal work by Staudinger showed that the molecular weight of poly(styrene) reduced after mastication. However, polymer mechanochemistry mainly focused on the destructive effects of mechanical force, until Moore reported that the azo‐mechanophore was cleaved selectively upon sonication in 2005. Afterwards, his group also found that mechanical force changed the reaction pathway of benzocyclobutene and made spiropyran display purple color under stress. In 2009, Sijbesma revealed that metal–NHC could be used as a latent catalyst to catalyze transesterification and polymerization. Subsequently, the Craig group disclosed the special mechanical reactivity of perfluorocyclobutane in 2011 and examined the influence of polymer backbone on the reactivity of epoxides in 2012. Later, they also reported that the lever‐arm effect enhanced gDBC or gDCC mechanochemistry. Since 2015, Otsuka's group has developed a series of mechanophores that generated various carbon radicals and showed different colors under mechanical force. De Bo subsequently investigated the effect of regio‐ and stereochemistry on the reactivity of furan–maleimide adduct in 2017, and he examined the different mechanisms of the mechanical activation of tetrafluorobenzene–NHC (N‐heterocyclic carbene) adduct in 2020. During that time, the Choi group explored the influence of polymer architecture on the mechanophore activation, and Robb's group utilized a furan‐maleimide adduct to achieve the release of different small molecules. In 2020, Göstl and Herrmann employed the scission of the disulfide within polymers to release drugs and reporting molecules by ultrasound, and the Chen group also investigated the mechanochemistry of diselenides which afforded selenium radicals. In 2021, Boydston's group realized the "flex‐activation" of NHC‐carbodiimide to release NHC small molecules. Recently, the Chen group achieved multistate mechanochromism by combining two Rh structures together through a conjugated connector. In addition, Robb designed a furan‐maleimide adduct to mechanically give a donor–acceptor Stenhouse adduct that reacted with different amines to display various colors. This review has focused on the chemistry of reactive species that are generated from mechanochemical reactions. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a heteroatom substitution strategy (HSS) in the δ‐valerolactone (VL) system to modulate thermodynamics toward chemically recyclable polyesters. Three VL‐based monomers containing different heteroatoms (M1 (N), M2 (S), and M3 (O)), instead of C‐5 carbon, were designed and synthesized to verify our proposed HSS. All three monomers undergo organocatalytic living/controlled ROP and controllable depolymerization. Impressively, the resulting P(M1) achieved over 99 % monomer recovery under both mild solution depolymerization and high vacuum pyrolysis conditions without any side reactions, and the recycled monomers can be polymerized again forming new polymers. The systematic study of the relationship between heteroatom substitution and recyclability shows that introducing heteroatoms does change the thermodynamics of the monomers (ΔHpo, ΔSpo and Tc values), thereby adjusting the polymerizability and depolymerizability. DFT calculations found that the introduction of heteroatoms adjusts the ring strain by changing the angular strain of the monomers, and the order of their angular strain (M2>M1>M3) is consistent with the order of the experimentally obtained enthalpy change. Notably, the one‐pot/one‐step copolymerization of two of each of the three monomers enables the synthesis of sequence‐controlled copolymers from gradient to random to block structures, by simply switching the copolymerization temperature. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a heteroatom substitution strategy (HSS) in the δ‐valerolactone (VL) system to modulate thermodynamics toward chemically recyclable polyesters. Three VL‐based monomers containing different heteroatoms (M1 (N), M2 (S), and M3 (O)), instead of C‐5 carbon, were designed and synthesized to verify our proposed HSS. All three monomers undergo organocatalytic living/controlled ROP and controllable depolymerization. Impressively, the resulting P(M1) achieved over 99 % monomer recovery under both mild solution depolymerization and high vacuum pyrolysis conditions without any side reactions, and the recycled monomers can be polymerized again forming new polymers. The systematic study of the relationship between heteroatom substitution and recyclability shows that introducing heteroatoms does change the thermodynamics of the monomers (ΔHpo, ΔSpo and Tc values), thereby adjusting the polymerizability and depolymerizability. DFT calculations found that the introduction of heteroatoms adjusts the ring strain by changing the angular strain of the monomers, and the order of their angular strain (M2>M1>M3) is consistent with the order of the experimentally obtained enthalpy change. Notably, the one‐pot/one‐step copolymerization of two of each of the three monomers enables the synthesis of sequence‐controlled copolymers from gradient to random to block structures, by simply switching the copolymerization temperature. [ABSTRACT FROM AUTHOR]

Light irradiation is an external stimulus, rapidly developed in switchable atom transfer radical polymerization (ATRP) via photo‐activation methods in recent years. Herein, a photo‐deactivation strategy is introduced to regulate ATRP with the assistance of photoswitchable hexaarylbiimidozole (HABI). Under visible light irradiation and in the presence of HABI, ATRP is greatly decelerated or quenched depending on the concentration of HABI. Interestingly, with visible light off, ATRP can proceed smoothly and follow a first‐order kinetics. Moreover, photo‐switchable ATRP alternatively with light off and on is demonstrated. Besides, the mechanism of photo‐deactivation ATRP involving radical quenching is proposed in the presence of HABI. [ABSTRACT FROM AUTHOR]

Since Hermann Staudinger coined the term "macromolecule" in the 1920s, one century of development of polymers in both academia and industry has had an overwhelming impact on human society. Furthermore, polymer chemists have made tremendous efforts to regulate polymer sequences, i.e., precisely arrange monomer units along the polymer chains to mimic DNA. To build a sustainable future of polymer manufacturing, bio-based monomers and eco-friendly degradable polymers have attracted immense interest in polymer communities. [Extracted from the article]

Poly(amino ester)s (PAEs) refer to a class of synthetic polymers characterized by repeating units in the backbone having tertiary amines and ester bonds, and bringing together the inherent biodegradability of polyesters and the rich tunable functionalities provided by tertiary amines. The presence of tertiary amines allows the introduction of various pendant groups, leading to diverse PAE material and properties, such as biodegradability, biocompatibility, water-solubility, stimulus-responsiveness (pH or temperature), etc. To date, PAEs are evolving into a new class of biodegradable polymer materials independent of aliphatic polyesters and have been widely used in various biomedical fields, such as gene delivery, drug delivery, bioimaging agents, etc. In addition, a new family of PAEs, namely N -acylated PAEs, with the same pendant carbonyl groups as poly(2-oxazoline)s, is expected to develop into new biopolymer platforms similar to polypeptoids and polyoxazolines. This review comprehensively summarizes the synthesis methods of PAEs, including polycondensation (PCD), Michael addition polymerization (MAP), spontaneous zwitterionic copolymerization (SZWIP), and ring-opening polymerization (ROP). [Display omitted] [ABSTRACT FROM AUTHOR]

ABSTRACT A series of selenium-substituted carbonates, S,Se-dibenzyl dithioselenocarbonate (DTSC), S,Se-dibenzyl thiodiselenocarbonate (TDSC), and Se,Se-dibenzyl triselenocarbonate (TSC), were synthesized and used as mediators in radical polymerization. The results indicate that these selenium-substituted carbonates can control the polymerization of styrene (St) and methyl acrylate, as evidenced by the number-average molecular weight that increased linearly with the monomer conversion, molecular weights that agreed well with the predicted values, and successful chain extensions. The treatment of the resultant polystyrene by hydrogen peroxide generated polymers with approximately half-reduced molecular weights, and the absence of carbonate groups and vinyl double bond-terminated chain ends. The polymerization with these selenium-substituted carbonates was the same polymerization mechanism as their analogue, the widely used S,S-dibenzyl trithiocarbonate. This work provided a flexible protocol to incorporate selenium into the polymer chain backbone. Specifically, the treatment of these polymers by oxidation produced 'clickable' vinyl-terminated chain ends, which provided possibilities for further functionalization, for example, via a thiol-ene click reaction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2606-2613 [ABSTRACT FROM AUTHOR]

A cyclic selenium-based reversible addition-fragmentation chain transfer (RAFT) agent, 5,5-dimethyl-3-phenyl-2-selenoxo-1,3-selenazolidin-4-one (RAFT-Se), was synthesized and utilized in the RAFT polymerizations of vinyl acetate (VAc). Its analog, 5,5-dimethyl-3-phenyl-2-thioxothiazolidin-4-one (RAFT-S), was also used in RAFT polymerizations for comparison under identical conditions. The RAFT polymerizations of VAc with RAFT-Se were moderately controlled evidenced by the increase of molecular weights with conversion, despite the slightly high Mw/ Mn (less than 1.90), whereas the molecular weights were poorly controlled in the presence of RAFT-S (2.00 < Mw/ Mn < 2.30). Thanks to its unusual cyclic structure of RAFT-Se, one or more RAFT-Se species was incorporated into the resultant poly(VAc) as revealed by the results of cleavage of polymer and atomic absorption spectroscopy. Considering the biorelated functions of both poly(VAc) and Se element, this work undoubtedly provided a successful methodology of how to incorporate high content of Se into a molecular weight controlled poly(VAc). © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 [ABSTRACT FROM AUTHOR]

Initiated by tetraethylthiuram disulfide, the solution polymerization of a new monomer, 2-(4-vinyl-benzyloxy)-naphthalene (VBN), which had naphthalene chromophore was successfully conducted in the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO). While using benzoyl peroxide as initiator, the polymerization was out of control under equal conditions. The poly(2-(4-vinl-benzyloxy)-naphthalene) (PVBN) and copolymer of VBN and styrene (poly(VBN-co-St)) had strong fluorescence emission at 350 nm, excited at 274 nm. Although the polystyrene (PS) had no fluorescence emission excited at 274 nm, the fluorescence intensities of poly(VBN-co-St) were enhanced with the increase of styrene feed ratio. [ABSTRACT FROM PUBLISHER]

In this work, zero-valent iron (Fe(0)) (powder or wire) and elemental bromine (Br2) were used as the catalysts for atom transfer radical polymerization (ATRP) of styrene (St) without any additional initiator at 110 °C. The polymerizations happened with controlled evidence at appropriate molar ratio of Fe(0) to Br2: a remarkable increase of molecular weights with St conversions, the narrow molecular weight distributions and living polymer chains end-capped by Br. More Br2 or less Fe(0) led to a slow polymerization rate but an improved control over molecular weights. After examining the polymer chain ends by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, it was concluded that the polymerization was initiated by thermal self-initiation, and regulated by the in situ generated FeIIIBr3. The results suggested that the Fe(0)/Br2 catalyzing polymerization was a classical ATRP process with easier operation and more economical components. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

In this work, cupric oxide (CuO) or cuprous oxide (Cu2O) was used as the catalyst for the single electron transfer-reversible addition-fragmentation chain transfer (SET-RAFT) polymerization of methyl methacrylate in the presence of ascorbic acid at 25 °C. 2-Cyanoprop-2-yl-1-dithionaphthalate (CPDN) was used as the RAFT agent. The polymerization occurred smoothly after an induction period arising from the slow activation of CuO (or Cu2O) and the 'initialization' process in RAFT polymerization. The polymerizations conveyed features of 'living'/controlled radical polymerizations: linear evolution of number-average molecular weight with monomer conversion, narrow molecular weight distribution, and high retention of chain end fidelity. From the polymerization profile, it was deduced that the polymerization proceeded via a conjunct mechanism of single electron transfer-living radical polymerization (SET-LRP) and RAFT polymerization, wherein CPDN acting as the initiator for SET-LRP and chain transfer agent for RAFT polymerization. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

In this work, bimetallic zero-valent metal (Fe(0) powder and Cu(0) powder) was used to mediate the single electron transfer-living radical polymerization (SET-LRP) of methyl methacrylate at 25 °C in dimethyl sulfoxide. Different feed ratios of [Fe(0)]0/[Cu(0)]0 (0/1.5, 0.5/1, 0.75/0.75, 1/0.5, and 1.3/0.2) were explored. With the increase of Fe(0) feed, the polymerization rate was mildly depressed with a prolonged induction period. While, the control over the molecular weights was improved upon the increase of Fe(0). A best control (initiation efficiency = 91%) was achieved at [Fe(0)]0/[Cu(0)]0 = 1/0.5. A further increase of Fe(0) to the feed ratio of [Fe(0)]0:[Cu(0)]0 = 1.3: 0.2 led to a uncontrolled polymerization. Explorations of available solvents and ligands for this polymerization confirmed the SET-LRP mechanism. It was suggested that Fe(0) might act as a dual role in this process: one was the activation agent for Cu(0), which favored a better control over the molecular weights; The other was an alternative catalyst for the activation of R-X or P n-X to generate radicals, which assured a comparable polymerization rate as that of Cu(0). This work provided an alternative and economical catalyst for SET-LRP, and would eventually reinforce the SET-LRP technique. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

For the first time, ligand-free Cu(0)-mediated polymerization of methyl methacrylate (MMA) was realized by the selection of ethyl-2-bromo-2-phenylacetate as initiator at ambient temperature. The polymerization can reach up to 90% conversion within 5 h with dimethyl sulfoxide (DMSO) as solvent, while keeping manners of the controlled radical polymerization. Extensive investigation of this system revealed that for a well-controlled Cu(0)-mediated polymerization of MMA, the initiator should be selected with the structure as alkyl 2-bromo-2-phenylacetate, and the solvent should be DMSO or N, N-dimethylformamide. The selectivity for solvents indicated a typical single-electron transfer-living radical polymerization process. Scanning for other monomers indicated that under equal conditions, the polymerizations of other alkyl (meth)acrylates were uncontrollable. Based on these results, plausible reasons were discussed. The ligand-free Cu(0)-mediated polymerization showed its superiority with economical components and needless removal of Cu species from the resultant products. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 [ABSTRACT FROM AUTHOR]

In this work, single electron transfer-living radical polymerization (SET-LRP) was catalyzed by in situ Cu(0) generated from copper sulphate pentahydrate (CuSO4·5H2O) and hydrazine hydrate (N2H4·H2O) at 25 °C. The polymerization occurred smoothly with moderate controllability: the polymerization rates increased by the increases of N2H4·H2O, and the initiator concentration had an optimal value on the polymerization rate; the number-average molecular weights ( Mn,GPC) increased with monomer conversions and polydispersities were below 1.40. The Mn,GPC deviated much from theoretical ones with about 50% polymer chain-end fidelities. Some side reactions stemming from the strong reduction performance of N2H4·H2O were responsible for the mildly controlled polymerizations. This polymerization can be conducted in SET-LRP unfavorable solvents or in bulk, such as toluene and tetrahydrofuran, owing to the H2O contained in CuSO4·5H2O and N2H4·H2O. On account of the utilization of CuSO4·5H2O, an inactive Cu(II) compounds in LRP area, this work confirmed from experimental level that it was Cu(0) which acted as activator and mediator in SET-LRP. This work provided a first example of in situ Cu(0) catalyzing SET-LRP with CuSO4·5H2O as a copper source. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]

In this work, atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out at room temperature (25 °C) under 60Co γ-irradiation environment. The polymerization proceeded smoothly with high conversion (>90%) within 7 h. The polymerizations kept the features of controlled radical polymerization: first-order kinetics, well-predetermined number-average molecular weights ( Mn,GPC), and narrow molecular weight distributions ( Mw/ Mn < 1.25). 1H NMR spectroscope and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry confirmed that poly(methyl methacrylate) (PMMA) chain was end-capped by the initiator moieties. The Cu(II) concentration could reduce to 20 ppm level while keeping good control over molecular weights. This is the first successful example for the ATRP of MMA under 60Co γ-irradiation at room temperature. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]

The copper(0)-catalyzed living radical polymerization of acrylonitrile (AN) was investigated using ethyl 2-bromoisobutyrate as an initiator and 2,2′-bipyridine as a ligand. The polymerization proceeded smoothly in dimethyl sulphoxide with higher than 90% conversion in 13 h at 25 °C. The polymerization kept the features of controlled radical polymerization. 1H NMR spectra proved that the resultant polymer was end-capped by ethyl 2-bromoisobutyrate species. Such polymerization technique was also successfully introduced to conduct the copolymerization of styrene (St) and AN to obtain well-controlled copolymers of St and AN at 25 °C, in which the monomer conversion of St could reach to higher than 90%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we designed and synthesized five novel reversible addition–fragmentation chain transfer (RAFT) agents bearing naphthyl moieties in the Z or R groups, including 3,4,5-trimethoxy-benzyl dithio-2-naphthalenoate (TOBDN), 4-nitrobenzyl dithio-2-naphthalenoate (NBDN), 1-menaphthyl 4-cyanodithiobenzoate (NCDB), 1-menaphthyl dithiobenzoate (NDB) and 1-menaphthyl dithio-2-naphthalenoate (NDN). The RAFT polymerizations of styrene mediated by these RAFT agents with AIBN as the initiator at 80°C were conducted and evaluated. Except for NCDB, the RAFT agents showed good control over the polymerization at different RAFT agent concentrations: the M n,GPC increased linearly with the monomer conversion, and the PDIs of the polymers were relatively low (PDI=1.20–1.50). The structure of RAFT agents bearing three different R groups with naphthyl as the Z group showed less effects on the polymerization rate, while those bearing different Z groups with 1-menaphthyl as the Resented significant effects on the polymerization rates. The polymerization rate with phenyl as the Z group was higher than that with 2-naphthyl as the Z group, and it decreased significantly when using 4-cycno phenyl as the Z group. Retardation effects were observed with all the RAFT agents. 1H NMR spectra and chain extension results confirmed that most of the polymer chains were “living”. Ultraviolet (UV) absorption of naphthyl moieties at the Rowed blue shifts compared with those of naphthyl at the Z group. The UV absorption intensity of PS was uniformly lower than that of the corresponding RAFT agent, while the fluorescence intensity of PS was higher than that of the corresponding RAFT agent. [Copyright &y& Elsevier]

Abstract: It would be ideal to have implants which can simultaneously inhibit bacterial adhesion and promote osteoblast functions. In this work, titanium surfaces were modified with poly(methacrylic acid) (P(MAA)) followed by immobilization of silk sericin. Firstly a trichlorosilane coupling agent, which is an atom transfer radical polymerization (ATRP) initiator, was immobilized on the oxidized titanium surface to facilitate the surface-initiated ATRP of methacrylic acid sodium salt (MAAS). The pendant carboxyl end groups of the grafted and partially protonated MAA chains were subsequently coupled with silk sericin via carbodiimide chemistry. The functionalized Ti surfaces were characterized by X-ray photoelectron spectroscopy, and assayed for osteoblast cell functions and bacterial adhesion. The covalently immobilized MAA brushes significantly reduce the adhesion of the two bacterial strains (Staphylococcus aureus and Staphylococcus epidermidis) tested. The silk sericin-immobilized surfaces, at the same time, promote osteoblast cells'' adhesion, proliferation, and alkaline phosphatase activity. Thus, the P(MAA) and silk sericin functionalized Ti surfaces have potential applications combating biomaterial-centered infection and promoting osseointegration. [Copyright &y& Elsevier]

Abstract: Reversible addition–fragmentation chain transfer polymerization (RAFT) of styrene (St) was carried out in the presence of oxygen using 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) or benzyl (2-phenyl)-1-imidazolecarbodithioate (BPIC) as the RAFT agent. The characteristics of the “living”/controlled radical polymerization were observed at high concentration of RAFT agent and low polymerization temperature. A slight increase in the rate of polymerization was found when oxygen was added at high concentration to the polymerization system; however, the presence of oxygen incurred greater polydispersities of the polymer at the same monomer conversion compared to that obtained in the absence of oxygen. The possible mechanism of the RAFT polymerization of St in the presence of oxygen was discussed. [Copyright &y& Elsevier]

Abstract: Thermal polymerization of methyl (meth)acrylate (MMA) was carried out using 2-cyanoprop-2-yl-1-dithionaphthalate (CPDN) and cumyl dithionaphthalenoate (CDN) as chain transfer agents. The kinetic study showed the existence of induction period and rate retardation, especially in the CDN mediated systems. The molecular weights of the polymers increased linearly with the monomer conversion, and the molecular weight distributions (M w/M ns) of the polymers were relatively narrow up to high conversions. The maximum number-average molecular weights (M ns) reached to 351 900g/mol (M w/M n =1.47) and 442 400g/mol (M w/M n =1.29) in the systems mediated by CPDN and CDN, respectively. Chain-extension reactions were also successfully carried out to obtain higher molecular weight PMMA and PMMA-block-polystyrene (PMMA-b-PSt) copolymer with controlled structure and narrow M w/M n. Thermal polymerization of methyl acrylate (MA) in the presence of CPDN, or benzyl (2-phenyl)-1-imidazolecarbodithioate (BPIC) also demonstrated “living”/controlled features with the experimented maximum molecular weight 312 500g/mol (M w/M n =1.57). The possible initiation mechanism of the thermal polymerization was discussed. [Copyright &y& Elsevier]

Fabrication of versatile hydrogels in a facile and effective manner represents a pivotal challenge in the field of biomaterials. Herein, a novel strategy is presented for preparing on‐demand degradable hydrogels with multilevel responsiveness. By employing selenol‐dichlorotetrazine nucleophilic aromatic substitution (SNAr) to synthesize hydrogels under mild conditions in a buffer solution, the necessity of additives or posttreatments can be obviated. The nucleophilic and redox reactions between selenol and tetrazine culminate in the formation of three degradable chemical bonds—diselenide, aryl selenide, and dearomatized selenide—in a single, expeditious step. The resultant hydrogel manifests exceptional adaptability to intricate environments in conjunction with self‐healing and on‐demand degradation properties. Furthermore, the resulting material demonstrated light‐triggered antibacterial activity. Animal studies further underscore the potential of integrating metformin into Se‐Tz hydrogels under green light irradiation, as it effectively stimulates angiogenesis and collagen deposition, thereby fostering efficient wound healing. In comparison to previously documented hydrogels, Se‐Tz hydrogels exhibit controlled degradation and drug release, outstanding antibacterial activity, mechanical robustness, and bioactivity, all without the need for costly and intricate preparation procedures. These findings underscore Se‐Tz hydrogels as a safe and effective therapeutic option for diabetic wound dressings. [ABSTRACT FROM AUTHOR]

Stimulus-responsive materials containing selenide under oxidizing conditions have wide application prospects, especially in biomedicine. Due to the intricate preparation process, the scarcity of studies on the structure–activity relationship of regulatory factors in the oxidative stimulus response poses challenges to material design. Herein, based on selenol-ene chemistry, a diverse library of unsymmetric selenides is synthesized, enabling systematic investigation into the regulation of selenide oxidative elimination with variable substituent groups and positions. The α/β-positions of β-carbonyl unsymmetric selenides are efficiently modified with electron-donating or electron-withdrawing groups through a one-pot, two-step reaction involving ammonolysis of γ-selenobutyrolactone (SBL), followed by nucleophilic addition with unsaturated acrylate. In situ NMR tracking shows that the oxidative elimination of selenide had a distinct substituent effect. Both the electron and steric effects of the substituent influence the induction period of the selenide oxidative and elimination reactions. With the optimal substituent and position, the selenides would exhibit a timebomb-type response upon oxidation stimulus. Finally, a novel amphiphilic polymer comprising selenide-linked polyethylene glycol (PEG) and cholesterol moieties is synthesized as a representative ROS-sensitive material and exhibits a time-dependent reduction in micelle size. [ABSTRACT FROM AUTHOR]

The photocatalyst Zn(II) meso‐tetra(4‐sulfonatophenyl)porphyrin (ZnTPPS) is found to substantially accelerate visible‐light‐initiated (red, yellow, green light) single unit monomer insertion (SUMI) of N,N‐dimethylacrylamide into the reversible addition–fragmentation chain transfer (RAFT) agent, 4‐((((2‐carboxyethyl)thio)carbonothioyl)thio)‐4‐cyanopentanoic acid (RAFT1), in aqueous solution. Thus, under irradiation with red (633 nm) or yellow (593 nm) light with 50 mpm (moles per million mole of monomer) ZnTPPS at 30 °C, the rate enhancement provided by photoinduced energy or electron transfer (PET) is ≈sevenfold over the rate of direct photoRAFT‐SUMI (without catalyst), which corresponds to achieving full and selective reaction in hours versus days. Importantly, the selectivity, as judged by the absence of oligomers, is retained. Under green light at similar power, higher rates of SUMI are also observed. However, the degree of enhancement provided by PET‐RAFT‐SUMI over direct photoRAFT‐SUMI as a function of catalyst concentration is less and some oligomers are formed. [ABSTRACT FROM AUTHOR]

Photoinduced 3D printing based on the reversible addition‐fragmentation chain transfer (RAFT) process has emerged as a robust method for creating diverse functional materials. However, achieving precise control over the mechanical properties of these printed objects remains a critical challenge for practical application. Here, we demonstrated a RAFT step‐growth polymerization of a bifunctional xanthate and bifunctional vinyl acetate. Additionally, we demonstrated photoinduced 3D printing through RAFT step‐growth polymerization with a tetrafunctional xanthate and a bifunctional vinyl acetate. By adjusting the molar ratio of the components in the printing resins, we finely tuned the polymerization mechanism from step‐growth to chain‐growth. This adjustment resulted in a remarkable range of tunable Young's moduli, ranging from 7.6 MPa to 997.1 MPa. Moreover, post‐functionalization and polymer welding of the printed objects with varying mechanical properties opens up a promising way to produce tailor‐made materials with specific and tunable properties. [ABSTRACT FROM AUTHOR]

Photoinduced 3D printing based on the reversible addition‐fragmentation chain transfer (RAFT) process has emerged as a robust method for creating diverse functional materials. However, achieving precise control over the mechanical properties of these printed objects remains a critical challenge for practical application. Here, we demonstrated a RAFT step‐growth polymerization of a bifunctional xanthate and bifunctional vinyl acetate. Additionally, we demonstrated photoinduced 3D printing through RAFT step‐growth polymerization with a tetrafunctional xanthate and a bifunctional vinyl acetate. By adjusting the molar ratio of the components in the printing resins, we finely tuned the polymerization mechanism from step‐growth to chain‐growth. This adjustment resulted in a remarkable range of tunable Young's moduli, ranging from 7.6 MPa to 997.1 MPa. Moreover, post‐functionalization and polymer welding of the printed objects with varying mechanical properties opens up a promising way to produce tailor‐made materials with specific and tunable properties. [ABSTRACT FROM AUTHOR]

Stimuli responsiveness has long been a fascinating feature of smart material design. Polydopamine (PDA), a nature inspired polymeric pigment, exhibits excellent photo-responsive properties and has active surface functionality for loading various responsive motifs, making it a promising candidate for the construction of stimuli-responsive smart functional materials. PDA has long been considered as a robust coating material, but its responsive feature has rarely been emphasized in the past reviews. Herein, we present the first effort to summarize recent advances in the design strategies, responsive mechanisms, and diverse applications of stimuli-responsive PDA-based smart materials; the stimuli include light, pH, chemicals, temperature, humidity, electric fields, mechanical force, magnetic fields, and ultrasound. Moreover, the current trends, challenges, and future directions of stimuli-responsive PDA-based materials are also elaborated. [ABSTRACT FROM AUTHOR]

Recently the research on the materials for removal of heave metals is surging rapidly. Here we have studied four triazine-based sulfur-containing polymers with different linkers, namely PDT1, PDT2, EDT1, and EDT2. They have been successfully synthesized by the nucleophilic substitution reaction of cyanuric chloride with propane-1,3-dithiol (PDT1 and PDT2) and ethane-1,2-dithiol (EDT1 and EDT2) in different ratios. The physical and chemical properties of these polymers were characterized by scanning electron microscopy, energy dispersive spectroscopy, Fourier transform infrared spectroscopy, porous structure analysis and X-ray photoelectron spectroscopy. The optimized adsorption condition was established by examining dosing, co-existing substances, contact time, concentration, temperature and pH values. The adsorbing properties, which was mainly described by the pseudo-second-order kinetic and Langmuir isothermal model, indicated that the sorption of Hg2+ was the chemical adsorption. The maximum Hg2+ sorption capacities of PDT1 , PDT2 , EDT1 and EDT2 were 1440.97 mg g−1, 715.99 mg g−1, 237.87 mg g−1 and 181.48 mg g−1, respectively. Thermodynamically, the adsorption of Hg2+ by the adsorbent is a spontaneous process. Cyclic experiments demonstrated that all the adsorbents could be reused in five successive adsorption cycles without significant losses in performance. Our density functional theory calculations in combination with relevant experimental results revealed the coordination geometry of Hg and hence mercury-adsorbent chelation mechanism. These results suggested that triazine-based sulfur-containing polymers could be utilized as effective adsorbents for the removal of Hg2+ from polluted water. [Display omitted] • Four triazine-based sulfur-containing polymers with different linker were readily prepared. • The polymers shown a higher adsorption capacity for Hg2+ (up to 1441 mg g−1) and could be easily reused. • Based on experimental facts and DFT calculations, the adsorption mechanism of the polymers was proposed. [ABSTRACT FROM AUTHOR]

To date, perovskite solar cells (pero‐SCs) with doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (Spiro‐OMeTAD) hole transporting layers (HTLs) have shown the highest recorded power conversion efficiencies (PCEs). However, their commercialization is still impeded by poor device stability owing to the hygroscopic lithium bis(trifluoromethanesulfonyl)imide and volatile 4‐tert‐butylpyridine dopants as well as time‐consuming oxidation in air. In this study, we explored a series of single‐component iodonium initiators with strong oxidability and different electron delocalization properties to precisely manipulate the oxidation states of Spiro‐OMeTAD without air assistance, and the oxidation mechanism was clearly understood. Iodine (III) in the diphenyliodonium cation (IP+) can accept a single electron from Spiro‐OMeTAD and forms Spiro‐OMeTAD⋅+ owing to its strong oxidability. Moreover, because of the coordination of the strongly delocalized TFSI− with Spiro‐OMeTAD⋅+ in a stable radical complex, the resulting hole mobility was 30 times higher than that of pristine Spiro‐OMeTAD. In addition, the IP‐TFSI initiator facilitated the growth of a homogeneous and pinhole‐free Spiro‐OMeTAD film. The pero‐SCs based on this oxidizing HTL showed excellent efficiencies of 25.16 % (certified: 24.85 % for 0.062‐cm2) and 20.71 % for a 15.03‐cm2 module as well as remarkable overall stability. [ABSTRACT FROM AUTHOR]

Unraveling the chirality transfer mechanism of polymer assemblies and controlling their handedness is beneficial for exploring the origin of hierarchical chirality and developing smart materials with desired chiroptical activities. However, polydisperse polymers often lead to an ambiguous or statistical evaluation of the structure–property relationship, and it remains unclear how the iterative number of repeating units function in the helicity inversion of polymer assemblies. Herein, we report the macroscopic helicity and dynamic manipulation of the chiroptical activity of supramolecular assemblies from discrete azobenzene‐containing oligomers (azooligomers), together with the helicity inversion and morphological transition achieved solely by changing the iterative chain lengths. The corresponding assemblies also differ from their polydisperse counterparts in terms of thermodynamic properties, chiroptical activities, and morphological control. [ABSTRACT FROM AUTHOR]

To date, perovskite solar cells (pero‐SCs) with doped 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene (Spiro‐OMeTAD) hole transporting layers (HTLs) have shown the highest recorded power conversion efficiencies (PCEs). However, their commercialization is still impeded by poor device stability owing to the hygroscopic lithium bis(trifluoromethanesulfonyl)imide and volatile 4‐tert‐butylpyridine dopants as well as time‐consuming oxidation in air. In this study, we explored a series of single‐component iodonium initiators with strong oxidability and different electron delocalization properties to precisely manipulate the oxidation states of Spiro‐OMeTAD without air assistance, and the oxidation mechanism was clearly understood. Iodine (III) in the diphenyliodonium cation (IP+) can accept a single electron from Spiro‐OMeTAD and forms Spiro‐OMeTAD⋅+ owing to its strong oxidability. Moreover, because of the coordination of the strongly delocalized TFSI− with Spiro‐OMeTAD⋅+ in a stable radical complex, the resulting hole mobility was 30 times higher than that of pristine Spiro‐OMeTAD. In addition, the IP‐TFSI initiator facilitated the growth of a homogeneous and pinhole‐free Spiro‐OMeTAD film. The pero‐SCs based on this oxidizing HTL showed excellent efficiencies of 25.16 % (certified: 24.85 % for 0.062‐cm2) and 20.71 % for a 15.03‐cm2 module as well as remarkable overall stability. [ABSTRACT FROM AUTHOR]

Unraveling the chirality transfer mechanism of polymer assemblies and controlling their handedness is beneficial for exploring the origin of hierarchical chirality and developing smart materials with desired chiroptical activities. However, polydisperse polymers often lead to an ambiguous or statistical evaluation of the structure–property relationship, and it remains unclear how the iterative number of repeating units function in the helicity inversion of polymer assemblies. Herein, we report the macroscopic helicity and dynamic manipulation of the chiroptical activity of supramolecular assemblies from discrete azobenzene‐containing oligomers (azooligomers), together with the helicity inversion and morphological transition achieved solely by changing the iterative chain lengths. The corresponding assemblies also differ from their polydisperse counterparts in terms of thermodynamic properties, chiroptical activities, and morphological control. [ABSTRACT FROM AUTHOR]

The development of multi‐component orthogonal polymerizations (MOPs) with simple procedure and high efficiency is crucial for rational polymer synthesis. In this work, photo‐triggered Cu(I)‐catalyzed azide‐alkyne cycloaddition (CuAAC) polymerization are first investigated, employing copper(II) thioxanthone carboxylate (Cu(TX)2) as photoredox catalyst and sunlight as stimuli. Then, the novel MOPs using one photoredox catalyst, Cu(TX)2 to simultaneously mediate two different photopolymerizations, are successfully realized in one‐pot, where photo‐induced electron transfer atom transfer radical polymerization and photo‐activated CuAAC polymerization can effectively proceed in a one‐pot and non‐interfering fashion to afford predetermined copolymers with well‐defined structure. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Mechanoredox chemistry that uses highly polarized piezoelectric materials as mechanoredox catalysts to promote redox reactions has emerged recently. It provides an alternative approach alongside the existing polymerization methods. Despite recent accomplishments, determining the quantitative relationship between the structure of ZnO and its catalytic performance for polymerization is still challenging. Herein, we prepared various ZnO crystals with different polar facets ratios to achieve efficient mechanically induced reversible addition‐fragmentation chain transfer polymerization (mechano‐RAFT). ZnO prepared from Zn(NO3)2 showed a high polar facet ratio of 1.66 and offered the highest catalytic activity among all ZnO samples. A near‐quantitative initiator efficiency of 99.5% and narrow molecular weight distribution were achieved for the polymerization of n‐butyl acrylate. Furthermore, the high chain‐end fidelity and chain extension capability were also evidenced by MALDI‐TOF MS and GPC analysis. This work highlighted the significant contribution of polar facets in ZnO to its catalytic activity and will guide the design of mechanoredox catalysis with superior catalytic performance in the future. [ABSTRACT FROM AUTHOR]

Modulating on‐demand polymerization is a challenge in synthetic macromolecules. Herein, tailoring polymerization controllability and dispersity during single‐electron transfer mediated living radical polymerization (SET‐LRP) of methyl methacrylate (MMA) is achieved. Hexaarylbiimidazole (HABI) is employed as a photoswitchable catalyst, allowing reversible control of catalytic activity between an active and inactive state. In the presence of HABI and with the light on (active state), control SET‐LRP of MMA follows first‐order kinetics, resulting in polymers with a narrow molecular weight distribution. In contrast, polymerization responds to light and reverts to their original uncontrolled state with light off (inactive state). Therefore, repeatable resetting polymerization can be easily performed. The key to photomodulating dispersity is to use an efficient molecular switch to tailor the breadths of dispersity. Besides, the mechanism of HABI‐mediated SET‐LRP with switchable ability is proposed. [ABSTRACT FROM AUTHOR]

Rational design of monomer sequence for desired properties is challenging. This study investigates the effect of monomer distribution of double hydrophilic copolymers (DHCs) with electron‐rich units on cluster triggered emission (CTE) capacity. By means of combining latent monomer strategy, reversible addition fragmentation chain transfer (RAFT) polymerization and selective hydrolysis technology, the random, pseudo di‐block and the gradient DHCs consisting of pH‐responsive polyacrylic acid (PAA) segments and thermo‐responsive poly(N‐isopropylacrylamide) (PNIPAM) segments were successfully synthesized in a controlled manner. Moreover, the gradient DHCs showed a tremendously increased luminescent intensity due to the distinct hydrogen‐bonding interaction compared to random and pseudo di‐block DHCs. To the best of our knowledge, this is the first reported the direct correlation between luminescent intensity and sequence structure of non‐conjugated polymer. Meanwhile, thermo and pH dual‐responsive clusteroluminescence could be easily performed. This work demonstrates a novel and facile method to tailor the hydrogen‐bonding for the stimuli‐responsive light‐emitting polymers. [ABSTRACT FROM AUTHOR]

Butyl acrylate is polymerized in the living way under the irradiation of purple light-emitting diode (LED) or sunlight without photocatalyst at ambient temperature. 2-((Phenoxycarbonothioyl)thio) ethyl propanoate) is exclusively added and acted as an initiator and a chain transfer agent simultaneously in the current system. Poly(butyl acrylate) with well-regulated molecular weight and relatively narrow molecular weight distribution ( Ð < 1.30) is synthesized. High conversion (>95%) can be achieved within several minutes. Polymerization shows oxygen tolerance. Near quantitative end-group fidelity of polymer is demonstrated by 1H NMR and matrix-assisted laser desorption/ionization time-of-flight mass spectra. [ABSTRACT FROM AUTHOR]

Photo-induced reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylonitrile was performed in a two-component system using 2-cyano-2-propyl dodecyl trithiocarbonate as the initiation-regulator dual-functional agent. The polymerization was carried out under mild conditions, e.g. under irradiation of blue light-emitting diode light at ambient temperature. Well-controlled polymers with high molecular weight and narrow molecular weight distribution were obtained. The light on and off experiments showed photosensitivity of this polymerization system. The structure of the obtained polymers was characterized by GPC and NMR. Polymers with molecular weight as high as M n = 286,300 g/mol could be obtained in optimized conditions. [ABSTRACT FROM AUTHOR]

Polypeptoids, structural mimics of polypeptides, have attracted considerable attention due to their biocompatibility, proteolytic stability, thermal processability, good solubility, synthetic accessibility, and structural diversity. Polypeptoids have emerged as an interesting material in both polymer science and biological field. This review primarily discusses the research progress of polypeptoids prepared by controlled ring‐opening polymerizations in the past decade, including synthetic strategies of monomers, polymerizations by different initiators, postfunctionalization, fundamental properties, crystallization‐driven self‐assembly, and potential biological applications. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Recently, piezocatalysis has attracted considerable attention as a new type of renewable mechanical energy conversion technology, which relies on the strain induced polarization of the piezoelectric material. This new technology has been extensively applied in the applications of water splitting, water remediation, gas purification and tumor therapy. Despite the rapid development in the piezocatalysis, the utilization of piezoelectric materials for synthetic purpose is still under exploration. Piezoelectric means to promote organic reactions expand the scope of piezoelectrically mediated reactions and show successes in both organic and polymer synthesis. Herein, we provide a comprehensive review on recent progress of piezoelectrically mediated reactions, catalytic mechanisms and applications in the last few years. The limitations and future directions of this area are also discussed. We believe this review will provide new insights into the underlying mechanism of piezoelectric mediated electron transfer process and guide the design of new chemistry. [ABSTRACT FROM AUTHOR]

Drug carriers and visual tracking play an important role in accurate and efficient drug delivery systems for targeted drug therapy. Polymerization‐induced self‐assembly (PISA), a powerful strategy for the fabrication of stimuli‐responsive polymeric nanoparticles has been a focus over the past decade due to its promising applications in biomedical fields such as targeted drug delivery and fluorescent nanoprobes used for tumor imaging. Herein, hypoxia‐responsive near‐infrared (NIR) fluorescent nanoprobes of amphiphilic block copolymers (PPEGMA14‐ADP‐Azo‐PBzMAx) are reported, the first example synthesized by RAFT‐mediated PISA strategy in situ to realize synchronous drug release and cell imaging. First, a series of nanoparticles with different morphologies and sizes, including spheres and vesicles, are synthesized by the PISA strategy using PPEGMA14‐ADP‐Azo‐CDPA as macro‐RAFT agents link with near‐infrared Aza‐BODIPY fluorogen and azobenzene groups. Hypoxia‐triggered dissociation of the nanoprobes and NIR fluorescence emission is then observed because of the cleavage of azo bonds. Meanwhile, the in situ DOX‐loaded nanoprobes by the PISA demonstrate synchronous drug release and NIR fluorescence enhancement against mouse colon cancer cells (CT26) under hypoxia (1% O2) compared with under normoxia (16% O2). [ABSTRACT FROM AUTHOR]

The self‐assembly of amphiphilic oligomers/polymers is a versatile and promising approach for creating nonspherical polymeric nanoparticles. Discrete amphiphilic oligomers/polymers with molecularly defined structures are ideal candidates for fabricating smart nanoparticles and for achieving a deeper understanding of structure‐controlled self‐assembly. Herein, discrete and disperse amphiphilic homopolymers of PAZOnTEG2n, with hydrophobic azobenzene are designed and synthesized as the main chains tethered with hydrophilic tetraethylene glycol monomethyl ether (TEG) units, to accurately investigate the impact of dispersity on their self‐assembly in solution. The discrete‐PAZO8TEG16 in DMF/water and in THF/water results in the formation of 2D lamellae, while the dispersed counterpart prefers to self‐assemble into spherical micelles. The significant difference is due to their distinction between interior structures of assembly. Furthermore, photoisomerization of azobenzene triggers dissociation/reassembly for discrete polymeric nanoparticles but no obvious change for the dispersed counterparts under irradiation with UV/vis light. This work reveals the influence of dispersity on the self‐assembly of amphiphilic polymers and stimuli‐responsive properties of their nanomaterials, which is desirable for universal applicability in fabricating smart 2D lamellas. [ABSTRACT FROM AUTHOR]

Digital polymers with precisely arranged binary units provide an important option for information storage. This is especially true if the digital polymers are assembled in a device, as it would be of great benefit for data writing and reading in practice. Herein, inspired by the DNA microarray technique, the programmable information storing and reading on a mass spectrometry target plate is proposed. First, an array of 4‐bit sequence‐coded dithiosuccinimide oligomers is efficiently built through sequential thiol‐maleimide Michael couplings with good sequence readability by tandem mass spectrometry (MS/MS). Then, toward engineering microarrays for information storage, a programmed robotic arm is specifically designed for precisely loading sequence‐coded oligomers onto the target plate, and a decoding software is developed for efficient readout of the data from MS/MS sequencing. Notably, short sequence‐coded oligomer chains can be used to write long strings of information, and extra error‐correction codes are not required as usual due to the inherent concomitant fragmentation signals. Not only text but also bitimages can be automatically stored and decoded with excellent accuracy. This work provides a promising platform of digital polymers for programmable information storing and reading. [ABSTRACT FROM AUTHOR]

The field of force-induced release of small cargoes within polymeric materials has experienced rapid growth over the past decade, not only including achieving diversified functional materials that report force, trigger degradation, activate drugs and release catalysts, but also involving investigations on the interesting force-coupled reactivity of mechanophores, such as ferrocenes. In this highlight article, we review the recent progress on polymer mechanochemistry that releases small cargoes, including small molecules and metal ions. Since mechanophores play a key role in force-responsive materials, we introduce the progress by discussing different types of mechanophores and their mechanochemical reactions for the release of acids, gases, fluorophores, drugs, iron ions, and so on. At the end, we provide our perspectives on the remaining challenges and future targets in this growing field. [ABSTRACT FROM AUTHOR]

ABSTRACT Vinyl-conjugated monomer (methyl acrylate, MA) and allyl 2-bromopropanoate (ABP)-possessing unconjugated CC and active CBr bonds were polymerized via the Cu(0)-mediated simultaneous chain- and step-growth radical polymerization at ambient temperature using Cu(0) as catalyst, N, N, N′, N″, N″-pentamethyldiethylenetriamine as ligand and dimethyl sulfoxide as solvent. The conversion was reached higher than 98% within 20 h. The obtained polymers showed block structure consisting of polyester and vinyl polymer moieties. The Cu(0)-catalyzed simultaneous chain- and step-growth radical polymerization mechanism was demonstrated by NMR, matrix-assisted laser desorption ionization time-of-flight, and GPC analyses. Furthermore, the obtained copolymers of MA and ABP were further modified with poly( N-isopropylamide) through radical thiol-ene 'click' chemistry from the terminal double bond. The thermoresponsive behavior of this block copolymer was investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3907-3916 [ABSTRACT FROM AUTHOR]

ABSTRACT The living free radical polymerizations of vinyl acetate (VAc) were successfully achieved in the presence of a novel organic selenium compound (diselenocarbonates), with 2,2′-azobisisobutyronitrile (AIBN) as the initiator. The living characteristics of the VAc polymerization were confirmed by the linear first-order kinetic plots and linear increase of molecular weights ( Mn) of the polymers with monomer conversions, while keeping the relatively low molecular weight distributions. In addition, the end of the polymers contains selenium element which may be useful in biotechnological and biomedical applications. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3159-3165 [ABSTRACT FROM AUTHOR]