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The insertion of an increasing amount of N -vinylpyrrolidone (VP) in statistical copolymers based on thermoresponsive poly(N-vinylcaprolactam) (PVCL) enables one to modulate the properties of the copolymer and those of the corresponding gold nanoparticles (AuNPs)-polymer hybrid materials. The incorporation of VP not only affects the growth of AuNPs synthesized in the presence of the polymers (in situ route), but also the properties (stabilization, optical, catalytic...) of preformed nanoparticles coated by these polymers. Hence, at a molar fraction of VP in copolymer less than 40%, it is possible to increase the transition temperature of the hybrid material and improve its catalytic properties compared to counterparts comprising PVP and PVCL homopolymers. The structural difference of the two monomers allows the best compromise between the hydration level and the interaction strength of the copolymer with the surface of gold particles for a chosen application. [Display omitted] • P(VCL/VP) 20k statistical copolymers of different compositions were used to prepare gold nanohybrids either from preformed gold nanoparticles or by an in situ approach. • Increasing the fraction of VCL in copolymer promotes its ability to act as efficient growth control agent of gold nanoparticles. • Thermoresponsiveness, colloidal stability and catalytic properties of obtained AuNPs@P(VCL/VP) can be tuned by adjusting VP and VCL content. [ABSTRACT FROM AUTHOR]

• Phase transitions and pseudo-continuous density vs pressure experimental data was obtained for 'carbon dioxide + acrylic acid' binary systems. • The phase boundaries were fitted using the RKPR cubic equation of state. • Excess volumes at high pressure were derived from density data and they show highly negative behavior. Acrylic acid can be polymerized by precipitation in different solvents. Carbon dioxide is an interesting solvent given its tunable density and solvent power depending on the pressure and temperature. These physicochemical characteristics make it possible to solubilize some polar compounds in CO 2 depending on temperature and pressure. In this work, we report pressure vs volume pseudo-continuous curves at constant temperature for the CO 2 + AA binary mixture. They were determined in a fully computerized variable-volume high-pressure view cell capable of monitoring the position of the piston. The experimental data is simultaneously isoplethic and isothermal and it covers a wide range of pressures (up to 20 MPa). Using this raw experimental data, other properties were determined such as liquid-vapor phase boundaries, density and excess volumes. The temperature range was 313.15–363.15 K and the mole fraction of AA in the mixture was increased from 0.044 to 0.594. [ABSTRACT FROM AUTHOR]

This study introduces bis(1-cyanocyclohex-1-yl)trithiocarbonate (TTC-bCCH) as a novel trithiocarbonate chain transfer agent and compares its reactivity with the previously described bis(2-cyanopropan-2-yl)trithiocarbonate (TTC-bCP) for the reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene (St), n-butyl acrylate (nBA), and methyl methacrylate (MMA). Significant findings include the effective control of M n and low dispersities from the onset of polymerization of St and nBA showing swift addition-fragmentation kinetics, leading to similar behaviors between the two RAFT agents. In contrast, a fourfold decrease of the chain transfer constant to MMA is established for TTC-bCCH over TTC-bCP. This trend is confirmed through density functional theory (DFT) calculations. Finally, the study compares thermoplastic elastomer properties of all-(meth)acrylic ABA block copolymers produced with both RAFT agents. The impact of dispersity of PMMA blocks on thermomechanical properties evaluated via rheological analysis reveals a more pronounced temperature dependence of the storage modulus (G') for the triblock copolymer synthesized with TTC-bCCH, indicating potential alteration of the phase separation., (© 2024 The Author(s). Macromolecular Rapid Communications published by Wiley‐VCH GmbH.)

Xanthates have long been described as poor RAFT/MADIX agents for styrene polymerization. Through the determination of chain transfer constants to xanthates, this work demonstrated beneficial capto-dative substituent effects for the leaving group of a new series of α-amido trifluoromethyl xanthates, with the best effect observed with trifluoroacetyl group. The previously observed Z-group activation with a O -trifluoroethyl group compared to the O -ethyl counterpart was quantitatively established with C ex = 2.7 (3-4 fold increase) using the SEC peak resolution method. This study further confirmed the advantageous incorporation of trifluoromethyl substituents to activate xanthates in radical chain transfer processes and contributed to identify the most reactive xanthate reported to date for RAFT/MADIX polymerization of styrene.

1,1'-Thiocarbonyldiimidazole (TCDI) readily undergoes radical copolymerization with tert -butyl acrylate ( t BA), N , N -dimethylacrylamide, and styrene. 1 H NMR monitoring of the comonomer reactivity revealed a notable compatibility between TCDI and comonomers, resulting in similar consumption rates when TCDI was introduced at a 10% feed ratio. Furthermore, trithiocarbonate-mediated RAFT copolymerization of TCDI with t BA gave polymers that exhibited a linear increase of molar mass ( M n th = 2-10 kg mol -1 ) with conversion with relatively low dispersities (1.2-1.4). Importantly, this process enabled a successful chain extension of the produced P(TCDI- co - t BA) copolymer with styrene to form a diblock copolymer. The copolymers generated through this method contain TCDI-derived diimidazolyl thioether moieties, as established through 1 H NMR spectroscopy. Additionally, degradation experiments using isopropylamine, benzoyl peroxide, sodium methoxide, and bleach have provided further confirmation of the presence of degradable TCDI moieties in the vinyl copolymer backbone.

Herein, we report the formation of drug delivery systems from original thermoresponsive block copolymers containing lipid-based segments. Two acrylate monomers derived from palmitic- or oleic-acid-based diacylglycerols (DAGs) were synthesized and polymerized by the reversible addition-fragmentation chain transfer (RAFT) method. Well-defined DAG-based polymers with targeted molar masses and narrow molar mass distributions were next used as macro-chain transfer agents (macro-CTAs) for the polymerization of N -isopropylacrylamide (NIPAAm) or N -vinylcaprolactam (NVCL). The obtained amphiphilic block copolymers were formed into polymeric nanoparticles (PNPs) with and without encapsulated doxorubicin and characterized. Their biological assessment indicated appropriate cytocompatibility with the representatives of normal cells. Furthermore, compared to the free drug, increased cytotoxicity and apoptosis or necrosis induction in breast cancer cells was documented, including a highly aggressive and invasive triple-negative MDA-MB-231 cell line.

Over the past few years, scientists have developed new ways to overcome the recycling issues of conventional thermosets with the introduction of associative covalent adaptable networks (i.e., vitrimers) in polymer materials. Even though various end-use vitrimers have already been reported, just a few of them have targeted high-performance industrial applications. Herein, we develop a promising high-performance epoxy vitrimer based on a commercially available resin widely used in aeronautics with the highest glass transition temperature ( T g ) of 233 °C ever reported for a vitrimer. A complete study of its physicochemical properties and cure kinetics was conducted, enabling the construction of the first time-temperature-transformation (TTT) diagram reported in the literature. This diagram allows a full determination of the processing and curing parameters leading to the manufacturing of vitrimer samples by the resin-transfer molding (RTM) process. The reshapability and limits therefrom of this high- T g vitrimer were evaluated by three successful thermoforming cycles without degradation.

Epoxy vitrimers encompass many advantages compared to traditional epoxy materials such as recyclability, repairability, and reprocessability. These properties are induced by the incorporation of dynamic reversible covalent bonds. Recently, the incorporation of aromatic disulfide bridges that are dynamic has expanded the development of new eco-friendly epoxy materials. Herein, we studied a bio-based aliphatic disulfide based on cystamine as a hardener with a vanillin-derived bio-sourced epoxy to prepare fully bio-based epoxy vitrimers. This article provides a comparative study between cystamine and an aromatic disulfide benchmark hardener issued from petrol resources. This work demonstrated that the presence of this aliphatic hardener has a significant influence not only on the reactivity, but most importantly on the resulting dynamic properties. An interesting yet counterintuitive accelerating effect of the dynamic exchanges was clearly demonstrated with only 2 to 20% of molar fraction of cystamine added to the aromatic disulfide formulation. A similar glass transition was obtained compared to the purely aromatic analogue, but relaxation times were decreased by an order of magnitude., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

Because of the formation of specific antibodies to poly(ethylene glycol) (PEG) leading to life-threatening side effects, there is an increasing need to develop alternatives to treatments and diagnostic methods based on PEGylated copolymers. Block copolymers comprising a poly( N -vinyl-2-pyrrolidone) (PVP) segment can be used for the design of such vectors without any PEG block. As an example, a poly(acrylic acid)- block -poly( N -vinyl-2-pyrrolidone) (PAA- b -PVP) copolymer with controlled composition and molar mass is synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Mixing this copolymer with lanthanide cations (Gd 3+ , Eu 3+ , Y 3+ ) leads to the formation of hybrid polyion complexes with increased stability, preventing the lanthanide cytotoxicity and in vitro cell penetration. These new nanocarriers exhibit enhanced T 1 MRI contrast, when intravenously administered into mice. No leaching of gadolinium ions is detected from such hybrid complexes.

Mixing double-hydrophilic block copolymers containing a poly(vinylphosphonic acid) block with gadolinium ions in water leads to the spontaneous formation of polymeric nanoparticles. With an average diameter near 20 nm, the nanoparticles are stable after dilution or change of pH and ionic strength. High magnetic relaxivities were measured in vitro, and in vivo magnetic resonance imaging on rats demonstrates the high potential of such polymeric assemblies.

We describe here a new methodology for the synthesis of well-defined phosphonic acid-terminated poly(ethylene glycol) (PEG) and RAFT-derived poly( N -vinylpyrrolidone) (PVP) and poly( N -vinylcaprolactam) (PVCL) by amine-thiol-ene and amine-thiol-thiosulfonate conjugation strategies using a phosphonated thiolactone and their use to prepare stable, water-dispersible multifunctional upconverting luminescent nanohybrids.

Bis(2-cyanopropan-2-yl)trithiocarbonate ( TTC-bCP ) is a new symmetrical trithiocarbonate with the best leaving group ever reported for reversible addition-fragmentation chain transfer (RAFT) polymerization. We propose an elegant route to obtain TTC-bCP starting from 2,2'-azobis(2-methylpropionitrile) (AIBN) as a donor of the 2-cyanopropan-2-yl group. TTC-bCP allowed the preparation of a high-molar-mass ( M n ≈ 135 kg mol -1 ) methyl methacrylate- n -butyl acrylate-methyl methacrylate triblock copolymer with unprecedented control ( D̵ = 1.04) in reversible-deactivation radical polymerization. Rheology measurements of this triblock copolymer showed a typical thermoplastic elastomer behavior with a steady rubbery plateau up to 120 °C.

Purpose: Efficient intracellular delivery of a therapeutic compound is an important feature of smart drug delivery systems (SDDS). Modification of a carrier structure with a cell-penetrating ligand, ie, cholesterol moiety, is a strategy to improve cellular uptake. Cholesterol end-capped poly( N -isopropylacrylamide)s offer a promising foundation for the design of efficient thermoresponsive drug delivery systems., Methods: A series of cholesterol end-capped poly( N -isopropylacrylamide)s (PNIPAAm) with number-average molar masses ranging from 3200 to 11000 g·mol -1 were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization from original xanthate-functionalized cholesterol and self-assembled into micelles. The physicochemical characteristics and cytotoxicity of cholesterol end-capped poly( N -isopropylacrylamide)s have been thoroughly investigated., Results: Phase transition temperature dependence on the molecular weight and hydrophilic/hydrophobic ratio in the polymers were observed in water. Biological test results showed that the obtained materials, both in disordered and micellar form, are non-hemolytic, highly compatible with fibroblasts, and toxic to glioblastoma cells. It was found that the polymer termini dictates the mode of action of the system., Conclusion: The cholesteryl moiety acts as a cell-penetrating agent, which enables disruption of the plasma membrane and in effect leads to the restriction of the tumor growth. Cholesterol end-capped PNIPAAm showing in vitro anticancer efficacy can be developed not only as drug carriers but also as components of combined/synergistic therapy., Competing Interests: All authors report no conflicts of interest in this work., (© 2020 Misiak et al.)

Simple and effective synthetic pathways are described to prepare compounds R 2 P(X)C(S)SCH(Me)Ph with the P atom either in the oxidation state V [R/X = t- Bu/O ( 6 ), Ph/S, ( 7 ), t- Bu/S ( 8 ), t- Bu/Se ( 9 )] or III [R/X = Ph/BH 3 ( 4 ), t- Bu/BH 3 ( 5 ), t- Bu/lone pair ( 10 )]. Compound 9 is the first example of carbodithioate ester with a P = Se group, and for the first time, a phosphinocarboditioate with a free phosphine function (compound 10 ) is described. Stabilization of the latter crucially depends on the steric protection by the t- Bu groups since an analogous derivative with R = Ph is observable but too unstable for isolation. Compound 10 can be reversibly protonated to yield the [ t- Bu 2 PHC(S)SCH(Me)Ph] + cation ( 10-H + ), which was isolated as a BF 4 - salt. A few interconversion processes resulting in the facile addition/removal or exchange of the X group in this family of compounds are also described. The oxidation state of the phosphorus atom and the nature of an electron-withdrawing group have a significant impact on the spectral properties.

A modular platform based on free-radical xanthate addition to alkenes enables access to a large series of functional γ-thiolactones. This methodology includes two different pathways based on xanthate chemistry involving radical addition and Chugaev elimination steps. The first method uses the addition of an ester-functionalized xanthate to various commercially functional alkenes, whereas the second one is based on the addition of functional xanthates to an ester-functionalized alkene. In both cases, a series of xanthate/alkene monoadducts was obtained, and their thermolysis and subsequent cyclization led to a library of functional γ-thiolactones in moderate to good yield. For a few cases where it may not be possible to directly incorporate some targeted functional groups via the proposed process involving free radicals and high temperature, a bromo-functionalized thiolactone was used as a starting material for chemical transformations., Competing Interests: The authors declare no competing financial interest.

A novel, one-step method for the synthesis of functional, organic-inorganic hybrid nanoparticles is reported. The quench ionic Flash NanoPrecipitation (qiFNP) method enables the straightforward synthesis of nanoparticles by decoupling the formation of the inorganic core and surface functionalization. As a proof-of-concept, the qiFNP method was successfully applied for the tunable and highly controlled synthesis of various LnPO4-based nanomaterials for bioimaging applications.

We apply the RAFT/MADIX technique to the micellar copolymerization of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid sodium salt with a hydrophobic monomer, 4- tert -butylstyrene. The resulting polymers have well-controlled molecular weight distributions. In the presence of sodium dodecyl sulfate, the polymerization is better controlled by an oligo-acrylamide chain transfer agent (PAm 7 -XA1) than by Rhodixan A1. The associative character of the polymer is maintained under RAFT polymerization conditions and chains can be extended to form block copolymers with associative segments.

This Review provides comprehensive guidelines for the design of CO2-philic copolymers through an exhaustive and precise coverage of factors governing the solubility of different classes of polymers. Starting from computational calculations describing the interactions of CO2 with various functionalities, we describe the phase behavior in sc-CO2 of the main families of polymers reported in literature. The self-assembly of amphiphilic copolymers of controlled architecture in supercritical carbon dioxide and their use as stabilizers for water/carbon dioxide emulsions then are covered. The relationships between the structure of such materials and their behavior in solutions and at interfaces are systematically underlined throughout these sections.

A new range of tin-based reversible addition-fragmentation chain-transfer (RAFT) agents is described and evaluated for the polymerization of acrylamides, methyl acrylate and styrene. These organometallic compounds are highly reactive reversible transfer agents which allow an efficient control of the polymerization of substituted acrylamide monomers, whereas RAFT control for methyl acrylate and styrene polymerization is contaminated by side reactions at prolonged reaction times. 119 Sn NMR is shown to be an informative instrument for the monitoring of Sn-RAFT-mediated polymerizations.

The novel monomer, vinyl trifluorobutyrate (VTFBu), when polymerized in a controlled fashion by RAFT/MADIX polymerization with a xanthate transfer agent, yields poly(vinyl ester)s with improved solubility in supercritical carbon dioxide. The thermodynamic parameters controlling the solubility of VTFBu/vinyl acetate statistical copolymers are discussed based on ab initio calculations, glass transition temperatures of the copolymers, and surface tension measurements. The enhanced solubility of this new class of CO 2 -philic polymer combined with its good chemical stability render it attractive for the preparation of next-generation macromolecular surfactants for the formation of water-scCO 2 emulsions.

Block copolymers enable combining properties of different polymers; double hydrophilic block copolymers are innovative examples. Size-exclusion chromatography (SEC or GPC) has a quasi-monopoly in separation-based characterization methods for polymers, including block copolymers. However, in terms of purity determination (unintended homopolymers present in the copolymers), SEC resolution proves insufficient except for the extreme compositions for which the second block is much larger than the first one. The free solution capillary electrophoresis (capillary zone electrophoresis) technique does not separate charged homopolymers by their molar mass and we thus named the corresponding method capillary electrophoresis in the critical condition (CE-CC). CE-CC provides a means to assess the purity of poly(acrylic acid-b-acrylamide) - P(AA-b-AM) - copolymers, as well as of the more challenging cationic poly(acrylamido-N-propyltrimethylammonium chloride-b-N-isopropylacrylamide)-P(APTAC-b-NIPAM). In addition it can identify that a block copolymer has been produced. It is to be noted that P(APTAC-b-NIPAM) block copolymers cannot be eluted in SEC due to their exceptional ability to adsorb onto surfaces, while some information is obtained from CE-CC. Both possible parent homopolymers can be detected and their quantity estimated in a single injection by CE-CC. In both cases, one of the parent homopolymers is neutral and comes with the electro-osmotic flow. If the electro-osmotic flow is weak (conditions used for the cationic copolymer) then pressure assisted CE-CC is used to detect this homopolymer., (Copyright © 2014. Published by Elsevier B.V.)

Molybdenum and chromium pentacarbonyldiphenylphosphinocarbodithioate complexes have been prepared in a one-pot reaction from the corresponding metallocarbonyldiphenylphosphine. The complexes have been characterised by IR, (1)H, (31)P and (13)C NMR spectroscopies and by mass spectrometry. The solid-state structures of [Cr(CO)(5){PPh(2)CS(2)CH(Ph)CH(3)}] (1) and [Mo(CO)(5){PPh(2)CS(2)CH(Ph)CH(3)}] (2) are reported. Compounds 1 and 2 are isostructural and crystallise in the triclinic P1 space group. These new organometallic compounds are highly efficient reversible chain-transfer agents for reversible addition-fragmentation chain-transfer (RAFT) polymerisation of styrene (St) and n-butyl acrylate (nBA), with controlled number-average molar mass values and narrow dispersities (<1.2). The controlled character of the polymerisation was further exemplified by the synthesis of St and nBA diblock copolymers., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)