Macromolecular Rapid Communications

In this contribution, we reported the transformation of polydicyclopentadiene (PDCPD) from thermoset into vitrimer. First, two N-coordinated diboronic diols were successfully synthesized via the reaction of N,N,N-tri(2-hydroxyethyl)amine and/or N,N,N",N"-tetrakis(2-hydroxyethyl)ethylene diamine with 4-(hydroxymethyl) phenylboronic acid and then they were transformed into two N-coordinated cyclic boronic diacrylates. The latter two dienes carrying electron-withdrawing substituents were used for the ring opening insertion metathesis copolymerization (ROIMP) of dicyclopentadiene to afford the crosslinked PDCPD...

Light irradiation is an external stimulus, rapidly developed in switchable atom transfer radical polymerization (ATRP) via photo-activation methods in recent years. Herein, we introduce a photo-deactivation strategy 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...

This communication reports an effective strategy helping address the long-troubling melt processing issue of isotactic polybutene-1 (i-PB) caused by its extremely slow II-I crystal phase transition. The solution lies in a facile synthesis of i-PB containing H-shape long-chain-branching structures (LCB-i-PB) by applying a so-called ω-alkenylmethyldichlorosilane copolymerization-hydrolysis (ACH) chemistry to butene-1 polymerization with Ziegler-Natta or metallocene catalysts. It is evident that the H-shape LCB structures effectively enhance chain entanglements of i-PB and induce an over-the-board acceleration of the overall melt crystallization process including nucleation, form II crystallization, and form II-form I phase transition...

Stroke is the second result for death and ischemic stroke constitutes most of all stroke cases. Ischemic stroke takes place when blood clot or embolus blocks cerebral vessel and interrupts blood flow, which often leads to brain damage, permanent disability, or death. There is a 4.5-hour (golden hour) treatment window to restore blood flow prior to permanent neurological impairment results. Current treatments of stroke consist mechanical system or thrombolytic drug therapy to disrupt or dissolve thrombus. Thrombolytics given more than 4...

This study investigates unexpected competitive host-guest interactions of β-cyclodextrin which can occur with polymers in aqueous solution, using the examples of the two polymers poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) and poly(glycerol mono methacrylate) (PGMA). Systematic structural modifications of the polymer provide insight into the host-guest interaction with β-cyclodextrin and the competition between side chains and end groups such as hydrophobic end groups remaining from reversible addition fragmentation chain transfer (RAFT) polymerization or intentionally implemented molecular recognition units such as arylazopyrazole (AAP) photoswitches...

The preparation of self-healing polyurethane elastomers (PUEs) incorporating dynamic bonds is of considerable practical significance. However, developing a PUE with outstanding mechanical properties and high self-healing efficiency poses a significant challenge. Herein, we have successfully developed a series of self-healing PUEs with various outstanding properties through rational molecular design. These PUEs incorporate m-xylylene diisocyanate and reversible dimethylglyoxime as hard segment, along with polytetramethylene ether glycol as soft segment...

Electrochromic devices built with ionogel electrolytes are seen as a pivotal step towards the future of quasi-solid electrochromic devices, due to their striking properties like exceptional safety and high ionic conductivity. Yet, the poor mechanical strength of electrolyte of these devices remains a constraint that hampers their advancement. As a resolution, this research explores the use of a robust, transparent ionogel electrolyte, which is designed using an in-situ microphase separation strategy. The ionogels are highly transparent and robust and exhibit excellent physicochemical stability, including a wide electrochemical window and high temperature tolerance...

Reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization of methyl methacrylate (MMA) is successfully performed in water in the presence of a poly(methacrylic acid) (PMAA) macromolecular chain transfer agent (macroCTA) leading to the formation of self-stabilized PMAA-b-PMMA amphiphilic block copolymer particles. At pH = 3.7, the reactions are well-controlled with narrow molar mass distributions. Increasing the initial pH, particularly above 5.6, results in a partial loss of reactivity of the PMAA macroCTA...

Within bioplastics, natural poly(3-hydroxybutyrate) (PHB) stands out as fully biocompatible and biodegradable, even in marine environments; however, its high isotacticity and crystallinity limits its mechanical properties and hence its applications. PHB can also be synthesized with different tacticities via a catalytic ring-opening polymerization (ROP) of β-butyrolactone (BBL), paving the way to PHB with better thermomechanical and processability properties. In this work, we extend our catalyst family based on aluminum phenoxy-imine methyl catalyst [AlMeL2], that revealed efficient in the ROP of BBL, to the halogeno analogous complex [AlClL2]...

Synthesis of monomer-recyclable polyesters solely from CO2 and bulk olefins holds great potentials in significantly reducing CO2 emissions and addressing the issue of plastic pollutions. Due to the kinetic disadvantage of direct copolymerization of CO2 and bulk olefins compared to homopolymerization of bulk olefins, considerable research attention has been devoted to synthesis of polyester via the ring-opening polymerization (ROP) of a six-membered disubstituted lactone intermediate, 1,2-ethylidene-6-vinyl-tetrahydro-2H-pyran-2-one (𝜹-L), obtained from telomerization of CO2 and 1,3-butadiene...

A new quinoline-based COF (Covalent Organic Framework), obtained by Povarov reaction, containing 2,6-diisopropylphenyl moieties as substituents over the heterocyclic ring is described for detecting Zn2+ in aqueous solution. The introduction of the mentioned bulky phenyl rings into the network favors an increase of the distance between the reticular sheets and their arrangement, obtaining a new material with an alternating AB type stacking. The new material exhibits good selectivity to detect Zn2+ by fluorescence emission in aqueous solutions up to a concentration of 1...

The collapse or folding of an individual polymer chain into a nanoscale particle gives rise to single-chain nanoparticles (SCNPs), which share a soft nature with biological protein particles. The precise control of their properties, including morphology, internal structure, size and deformability, have been a long-standing and challenging pursuit. Herein, a new strategy based on amphiphilic alternating copolymers for producing SCNPs with ultrasmall size and uniform structure has been presented. SCNPs were obtained through folding the designed alternating copolymer in DMF and fixing it through a photocatalyzed cycloaddition reaction of anthracene units...

Hydrogels are usually depicted as a homogenous polymer block with a distinct surface. While defects in the polymer structure are looked into frequently, structural irregularities on the hydrogel surface are often neglected. In this work, thin hydrogel layers of about 100 nm thickness (nanogels) have been synthesised and characterised for their structural irregularities, as they represent the surface of macrogels. The nanogels contain a main-chain responsiveness (thermo responsive) and a responsiveness in the cross-linking points (redox responsive)...

We showcase self-oscillating gel systems exhibiting an expanded operating temperature and accompanying functional adaptability. The developed system contains nonthermoresponsive main-monomers, such as N,N-dimethylacrylamide (DMAAm) or 2-acrylamido-2-methylpropane sulfonic acid (AMPS) or acrylamide (AAm) or 3-(methacryloylamino)propyl trimethylammonium chloride (MAPTAC). The gels volumetrically self-oscillates within the range of the conventional (20.0 °C) and extended (27.0 and 36.5 °C) temperatures...

This work reports preparing thermal responsive poly (N-isovinylcaprolactam) (PNVCL) microgel based films for cell growth and detachment. PNVCL microgels of hydrated size ranging from 386 to 815 nm (25 °C) and different crosslinking degree are prepared. The PNVCL microgels can be rapidly and massively deposited on glass by spin coating method. Atomic force microscopy (AFM) and water contact angle (WCA) are used to study the influence of crosslinking degree and particle size on the surface morphology, stability and hydrophilicity of PNVCL microgel film...

The investigation of chiral supramolecular stacking is of essential significance for the understanding of the origin of homochirality in nature. Unlike structurally well-defined amphiphilic liposomes, it remains unclear whether the solvophilic segments of the amphiphilic block copolymer play a decisive role in the construction of asymmetric superstructures. Herein, we present insights into the stacking patterns and morphological regulation in azobenzene-containing block copolymer assemblies solely by modulating the solvophilic chain length...

Protein-polymer conjugates and polymeric nanomaterials hold great promise in many applications including biomaterials, medicine or nanoelectronics. In this work, we present the first PISA (polymerization-induced self-assembly) approach performed in aqueous medium enabling protein-polymer conjugates and nanoparticles entirely composed of amino acids by using ring-opening polymerization (ROP). We indeed show that aqueous ROPISA can be used with protein or peptidic macroinitiators without prior chemical modification and afford the simple preparation of nanomaterials with protein-like property, for example to implement biomimetic thermoresponsivity in drug delivery...

Conductive hydrogels play a crucial role in advancing technologies like implantable bioelectronics and wearable electronic devices, owing to their favorable conductivity and appropriate mechanical properties. Here, we report a novel bottom-up approach for crafting conductive nanocomposite hydrogels to achieve enhancing conductive and mechanical properties. In this approach, new poly(ɛ-caprolactone)-based block copolymers with sulfonic groups were first synthesized and self-assembled into uniform polyanionic nanoplatelets...

Droplet-based microfluidics-assisted fabrication of alginate microgels has extensive applications in biomaterials, biomedicines, and related fields. This approach is typically achieved by crosslinking droplets of an aqueous solution of sodium alginate with various divalent and trivalent ions, such as Ca2+ , Ba2+ , Sr2+ , etc. Despite the exceptional features exhibited by bulk alginate hydrogels when using Iron ions as the crosslinking reagent, including stimulus responsiveness and complex chemistry, no attention has been given to studying the fabrication of Fe-alginate microgels through droplet microfluidics...

High sulfur content polymeric materials, known for their intriguing properties such as high refractive indices and high electrochemical capacities, have garnered significant interest in recent years for their applications in optics, antifouling surfaces, triboelectrics, and electrochemistry. Despite the high interest, most high sulfur-content polymers reported to date are either bulk materials or thin films, and there is a general lack of research into sulfur-rich polymer colloids. Water-dispersed, sulfur-rich particles are anticipated to broaden the range of applications for sulfur-containing materials...