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The application of bio-based solvents for living radical polymerization has been a hot topic in recent year. In this article, γ-valerolactone (GVL), a bio-based solvent as green media for ARGET atom transfer radical polymerization (ATRP) of styrene (St) were investigated. We first conducted polymerization of St in γ-valerolactone using copper(ii) bromide as the catalyst, tris(2-pyridylmethyl) amine as the ligand, and only sodium ascorbate as reducing agent. The polymerization achieved moderate conversion; however, the controllability of polymerization was not very good, providing a polymer with a broad molecular weight distribution (M w/M n > 1.30). When sodium carbonate is introduced, excellent results were obtained providing high yields and low M w/M n values under very low catalyst usage (∼5 ppm). 1H NMR spectroscopy, chain extension, and MALDI–MS experiments confirmed the final polymer chains with high fidelity. The use of GVL solvent opens a new route for the easy synthesis of PS through ARGET ATRP with low catalyst usage conditions.

This experiment addresses the challenge of understanding the abstract concept of "living" in living radical polymerization within the undergraduate teaching of polymer chemistry course. We conducted a 3D printing experiment using photo-induced reversible addition-fragmentation chain transfer (RAFT) polymerization. Initially, we synthesized O-(ethyl)-S-(2-propyl ethanoate thio) xanthate (EXEP) under optimized conditions. Subsequently, 3D printing was performed with commercial photosensitive resin under conditions with and without EXEP. The printed structures were then subjected to post-modification with a fluorescent monomer, and a comparative experiment on polymer welding was conducted. By analyzing and comparing the experimental results, we aimed to visually demonstrate the mechanism of living radical polymerization and its impact on post-functionalization. This experiment seamlessly integrates foundational theory into an engaging practical context. It is characterized by its reasonable duration, simplicity in operation, significant outcomes, and alignment with basic requirements for undergraduate teaching experiments. Furthermore, it contributes to enhancing students' comprehensive analytical abilities, sparking their interest in deeper research, and cultivating their innovative awareness and extension capabilities. [ABSTRACT FROM AUTHOR]

Herein, we developed a reversible complexation mediated polymerization (RCMP) starting with a complex of iodine and organic salt as a deactivator and a thermal initiator for continuous regeneration of the organic salt activator. This novel polymerization method can be called as initiators for continuous activator regeneration (ICAR) RCMP, as inspired by the denomination of ICAR ATRP. The synthesis of poly (methyl methacrylate) (PMMA) (Mw/Mn < 1.3) with good controllability was achieved via this technique when the concentration of the deactivator complex was as low as dozens of ppm. The studied three kinds of iodine complexes showed high control on the polymerization of MMA. The effects of initiator and deactivator complex concentration on the polymerization process were researched in detail. Furthermore, the accessibility of PMMA prepared by ICAR RCMP to chain extension and block copolymerization confirmed that this novel polymerization approach afforded polymers with high chain-end fidelity. The substantial decrease in the concentration of deactivator complex or activator plays a critical role for the production and application of well-defined polymer prepared by this method. [ABSTRACT FROM AUTHOR]

Polymerization‐induced self‐assembly (PISA) is conducted in a non‐polar medium (n‐dodecane) via reversible complexation‐mediated polymerization (RCMP). Stearyl methacrylate (SMA) is used to synthesize a macroinitiator, and subsequent block polymerization of benzyl methacrylate (BzMA) from the macroinitiator in n‐dodecane afforded a PSMA–PBzMA block copolymer, where PSMA is poly(stearyl methacrylate) and PBzMA is poly(benzyl methacrylate). Because PSMA is soluble but PBzMA is insoluble in n‐dodecane, the block copolymer formed a self‐assembly during the block polymerization (PISA). Spherical micelles, worms, and vesicles are obtained, depending on the degrees of polymerization of PSMA and PBzMA. "One‐pot" PISA is also attained; namely, BzMA is directly added to the reaction mixture of the macroinitiator synthesis, and PISA is conducted in the same pot without purification of the macroinitiator. The spherical micelle and vesicle structures are also fixed using a crosslinkable monomer during PISA. RCMP‐PISA is highly attractive as it is odorless and metal‐free. The "one‐pot" synthesis does not require the purification of the macroinitiator. RCMP‐PISA can provide a practical approach to synthesize self‐assemblies in non‐polar media. [ABSTRACT FROM AUTHOR]

Droplet‐based microfluidics represents a disruptive technology in the field of chemistry and biology through the generation and manipulation of sub‐microlitre droplets. To avoid droplet coalescence, fluoropolymer‐based surfactants are commonly used to reduce the interfacial tension between two immiscible phases to stabilize droplet interfaces. However, the conventional preparation of fluorosurfactants involves multiple steps of conjugation reactions between fluorinated and hydrophilic segments to form multiple‐block copolymers. In addition, synthesis of customized surfactants with tailored properties is challenging due to the complex synthesis process. Here, we report a highly efficient synthetic method that utilizes living radical polymerization (LRP) to produce fluorosurfactants with tailored functionalities. Compared to the commercialized surfactant, our surfactants outperform in thermal cycling for polymerase chain reaction (PCR) testing, and exhibit exceptional biocompatibility for cell and yeast culturing in a double‐emulsion system. This breakthrough synthetic approach has the potential to revolutionize the field of droplet‐based microfluidics by enabling the development of novel designs that generate droplets with superior stability and functionality for a wide range of applications. [ABSTRACT FROM AUTHOR]

One‐pot synthesis of methacrylic and acrylic polymers from benzylic alcohols (R−OH) used as initiating moieties was developed. R−OH was converted to alkyl iodide (R−I), and the generated R−I was used as an initiator without purification or isolation in the subsequent reversible complexation mediated polymerization (RCMP), leading to one‐pot RCMP from R−OH. As a useful application, this technique was exploited for one‐pot polymer‐grafting from lignin that is the second most abundant renewable carbon‐source on earth and bears benzylic alcohols. The direct initiation from lignin eliminates tedious initiator attachment and purification, offering a facile access to polymer‐grafted lignin. The obtained polymer‐grafted lignin was utilized to form an efficient UV‐absorbing film with high transparency in visible region. One‐pot RCMP may serve as a practical method to obtain value‐added functional lignin‐polymer composites. [ABSTRACT FROM AUTHOR]

Comb‐shape, block copolymers from hydrophilic poly(ethylenglycol) monomethyl ether acrylate (mPEGA, A) and hydrophobic 2‐ethylhexyl acrylate (EHA, B) are synthesized by copper(0)‐mediated single‐electron transfer living radical polymerization (SET‐LRP) via sequential addition of the two monomers, resulting in different compositions (AB, ABA, BAB, BA), molar masses, and mPEGA/EHA ratios. All polymers show narrow molar mass distributions and molecular weights of 7.7–25.50 kg mol−1, demonstrating precise control over the polymerization and molecular weights through the utilization of SET‐LRP. Kinetic experiments are conducted to investigate the polymerization behavior of mPEGA and EHA in N,N‐dimethylformamide as a rather uncommon solvent for SET‐LRP further underlining a living‐type polymerization. Amphiphilic properties are investigated by critical micelle concentration (CMC) measurements and formation of micelles in water. A reverse relation between mPEGA/EHA ratio and CMC values reveals that an increased hydrophobicity leads to decreased CMC values. The self‐assembly behavior of polymers in water confirms the formation of uniform and stable micelles in water with a size between 12 and 184 nm depending on the composition of the polymers. With increased hydrophilicity, micelle sizes increase as well. In vitro tests of the obtained polymers show excellent biocompatibility even at high concentrations further affirming their suitability for drug delivery applications. [ABSTRACT FROM AUTHOR]

The modification of polymer chain ends is important in order to produce highly functional polymers. A novel chain-end modification of polymer iodides (Polymer-I) via reversible complexation-mediated polymerization (RCMP) with different functionalized radical generation agents, such as azo compounds and organic peroxides, was developed. This reaction was comprehensively studied for three different polymers, i.e., poly (methyl methacrylate), polystyrene and poly (n-butyl acrylate) (PBA), two different functional azo compounds with aliphatic alkyl and carboxy groups, three different functional diacyl peroxides with aliphatic alkyl, aromatic, and carboxy groups, and one peroxydicarbonate with an aliphatic alkyl group. The reaction mechanism was probed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The combination of PBA-I, iodine abstraction catalyst and different functional diacyl peroxides enabled higher chain-end modification to desired moieties from the diacyl peroxide. The dominant key factors for efficiency in this chain-end modification mechanism were the combination rate constant and the amount of radicals generated per unit of time. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cu(0)-catalyzed single-electron transfer-living radical polymerization (SET-LRP) has shown great potential for applications in which well-defined chain end-functionalized polymers are demanded as final products or as intermediates. However, the use of polar reaction media favoring the disproportionation of Cu(I)X species into Cu(0) and Cu(II)X2 was considered a limiting factor specially in the synthesis of complex hydrophobic polymers with functional chain ends. “Self-generated” biphasic systems, in which the polymer phase-separates from the homogeneous reaction mixture above a certain molecular weight, together with fundamental studies on the role of solvent, including catalytic solvent effect, and methodological developments such us the “mixed-ligand” concept served as inspiration, although sometimes in an unknown way, to solve this problem. Today, SET-LRP of both acrylic and methacrylic vinyl monomers is already feasible in both polar and non-polar non-disproportionating solvents using their corresponding bi(multi)phasic “programmed” mixtures with water. Under these conditions, SET-LRP is an interfacial process in which disproportionation and activation events occur independently in the aqueous and organic compartments, and the “self-controlled” reversible deactivation takes place at the interface. Consequently, this design entirely defeats the limiting requirement to exclusively use disproportionating solvents. After a brief discussion of the historical evolution of the field of LRP, starting with the landmark work of Otsu from 1950th, this feature article will describe the elaboration of “programmed” bi(multi)phasic SET-LRP systems starting from initial inspiration to development in laboratory large-scale experiments.

A mild organocatalyzed living radical polymerization method is studied for high molecular weight polymers (HMWPs), yielding low‐dispersity linear and star polymers (Đ = Mw/Mn = 1.03–1.28) up to Mn = 3.9 × 105 and monomer conversion = 80%, where Mn and Mw are the number‐ and weight‐average molecular weights, respectively. Even at high degrees of polymerization (DPs > 2000), this technique still features excellent control over molecular weights and Đ values, indicating the living character. The macroinitiators prepared at DP = 2000 are subsequently used for block polymerizations at high DPs (>2000) with functional methacrylates, yielding linear A‐B diblock, linear B‐A‐B triblock, and 3‐arm star A‐B diblock copolymers, suggesting the excellent block efficiency of macroinitiators synthesized at a high DP value (=2000). This mild organocatalyzed living radical polymerization technique can enhance the livingness of propagation radicals and kinetic chain length at high monomer conversions for monomers with moderate propagation rate coefficients (kps), reduce the persistent radical effect as much as possible, and hence enable HMWPs without the presence of metal catalyst, exogenous initiator, or harsh equipment. The obtained amphiphilic block copolymers present unique microphase separation behavior, and hold great potential in advanced materials applications, for example, thermosensitive nanocarriers. [ABSTRACT FROM AUTHOR]

This work reports the first use of organic chloride salts as catalysts for reversible complexation mediated living radical polymerization. Owing to the strong halogen‐bond forming ability of Cl−, the studied four tetraalkylammonium chloride catalysts (R4N+Cl−) successfully control the polymerizations of methyl methacrylate, yielding polymers with low dispersities up to high monomer conversion (>90%). Benzyldodecyldimethylammonium chloride is further exploited to other methacrylates and yields low‐dispersity block copolymers. The advantages of the chloride salt catalysts are wide monomer scope, good livingness, accessibility to block copolymers, and good solubility in organic media. Because of the good solubility, the use of the chloride salt catalysts can prevent agglomeration of catalysts on reactor walls in organic media, which is an industrially attractive feature. Among halide anions, chloride anion is the most abundant and least expensive halide anion, and therefore, the use of the chloride salt catalysts may lower the cost of the polymerization. [ABSTRACT FROM AUTHOR]

An air‐tolerant reversible complexation mediated polymerization (RCMP) technique, which can be carried out without prior deoxygenation, is developed. The system contains a monomer, an alkyl iodide initiating dormant species, air (oxygen), an aldehyde, N‐hydroxyphthalimide (NHPI), and a base. Oxygen is consumed via the NHPI‐catalyzed conversion of the aldehyde (RCHO) to a carboxylic acid (RCOOH). The generated RCOOH is further converted to a carboxylate anion (RCOO−) by the base. The RCOO− generated in situ works as an RCMP catalyst; the polymerization proceeds with the monomer, alkyl iodide dormant species, and RCOO− catalyst. Thus, the system is not only air‐tolerant but also does not require additional RCMP catalysts, which is a notable feature of this system. (NHPI is used as an oxidation catalyst for converting RCHO to RCOOH.) This technique is amenable to methyl methacrylate, butyl methacrylate, benzyl methacrylate, 2‐hydroxyethyl methacrylate, and styrene, yielding polymers with relatively low‐dispersity (Mw/Mn = 1.20−1.49), where Mw and Mn are the weight‐ and number‐average molecular weights, respectively. [ABSTRACT FROM AUTHOR]

Kinetic studies have shown that the use of systems based on secondary and tertiary hydroperoxides with N, N-diethyldithiocarbamate copper (II) can be used as effective sources of free radicals in the polymerization of methyl methacrylate in moderately low temperatures region (323-343 K). The introduction of an aromatic ring in molecules of hydroperoxides (ethylbenzene hydroperoxide and cumene hydroperoxide) increases the reactivity of the initiating system «hydroperoxide - complex» in comparison with tertiary butyl hydroperoxide. The shift of the gel effect to the region of high conversions during the polymerization of methyl methacrylate was noted. Such systems allow not only to accelerate the polymerization of the monomer, but also to conduct it in a controlled mode. H1 NMR spectroscopy showed that the formed polymers contained end dithiocarbamate fragments. Such groups are labile. It has been shown that the obtained and isolated in the presence of the initiating system tertiary hydroperoxide - N,N-diethyldithiocarbamate of copper(II) polymers are macroinitiators that can initiate a new portion of the monomer. [ABSTRACT FROM AUTHOR]

Reversible addition–fragmentation chain transfer (RAFT) polymerization of 2‐(tert‐butoxycarbonyloxy)ethyl methacrylate (BHEMA) is carried out using 4‐cyano‐4‐((dodecylsulfanylthiocarbonyl)sulfanyl)pentanoic acid as the RAFT agent. The polymers with a controlled molecular weight and polydispersity are produced when a large amount of the RAFT agent is used. The RAFT polymerization of isobutyl methacrylate is also carried out using poly(2‐(tert‐butoxycarbonyloxy)ethyl methacrylate) (PBHEMA) as the macro‐RAFT agent in order to synthesize diblock copolymers with a narrow molecular weight distribution. It is revealed that the control of the polymerization of BHEMA is achieved under limited polymerization conditions. Then, the acid‐catalyzed deprotection of tert‐butoxycarbonyloxy groups of PBHEMA is performed in the presence of trifluoroacetic acid at room temperature to obtain polymers with a hydroxy group in the side chain. The hydroxy‐containing polymers are further reacted with 2‐isocyanatoethyl acrylate and methacrylate to synthesize precursor polymers used for a thermally curing system. [ABSTRACT FROM AUTHOR]

ABC‐type miktoarm star copolymers are synthesized using a single living radical polymerization (organocatalyzed living radical polymerization) via a "combinatorial" approach. The arm A is poly(butyl acrylate), the arm B is poly(methyl methacrylate), and the arm C encompasses hydrophobic and hydrophilic polyacrylates. A poly(butyl acrylate) with a vinyl chain end (macromonomer) is synthesized. A poly(methyl methacrylate) is subsequently connected to the reactive vinyl group to generate diblock copolymer. From the junction of the diblock copolymer, polymer C grew to yield star copolymers. An amphiphilic star copolymer is also synthesized, and its self‐assembly structure is studied in an aqueous solution. [ABSTRACT FROM AUTHOR]

Electrode binders have significant influences on lithium-ion battery performance. Good binders should be able to absorb electrolyte to accelerate lithium-ion transport while simultaneously maintaining adequate adhesion and mechanical strength after swelling. Currently, most polymer binders are based on homo or random copolymers so they may only meet one of these requirements, as an improvement in electrolyte swelling ability is detrimental to mechanical strength, and vice versa. This work investigates whether the design of chain sequence can resolve this contradiction. Reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization is employed to synthesize copolymer latex with different chain sequences as electrode binders, which are examined in both LiFePO4 cathode and silicon anodes. The results show a triblock copolymer chain sequence gives the best performance. The microphase separation in triblock copolymer distributes functionalities of electrolyte affinity and strength maintenance into disparate blocks and therefore satisfies both requirements simultaneously. The advantages of triblock chain sequence are demonstrated by superior ionic conductivity, mechanical strength after electrolyte absorption, and lithium-ion diffusion coefficient and then lead to better battery performance compared with random counterpart and commercial aqueous binders. [ABSTRACT FROM AUTHOR]

Two kinds of Schiff base, N,N′‐dibenzylidene‐1,2‐diaminoethane (NDBE) and N,N′‐disalicylidene‐1,2‐diaminoethane, have been found as efficient organic catalyst for reversible complexation‐mediated radical polymerization (RCMP) of methyl methacrylate (MMA) for the first time. The polymerization results show obvious features of "living"/controlled radical polymerization. Well‐defined and low‐polydispersity polymers (Mw/Mn = 1.20–1.40) are obtained in RCMP of MMA catalyzed by Schiff base at mild temperature (65–80°C). Moreover, Schiff base also exhibits a particularly high reactivity for RCMP of MMA with in situ formed alkyl iodide initiator. The polymer molecular weight and its polydispersity (Mw/Mn is around 1.20) are well controlled even with high monomer conversion. Notably, when the dosage of azo initiator is same as the dosage of iodine, the polymerization could also be realized in the presence of NDBE. The living feature of synthesized polymer is confirmed through the chain extension experiment. In short, Schiff base is a kind of high‐efficient catalyst for RCMP and reverse RCMP of MMA, which can be one of the most powerful and robust techniques for polymer synthesis. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1653–1663 [ABSTRACT FROM AUTHOR]

Block copolymers containing polytetrahydrofuran segments were synthesized by umpolung or propagating end of the cationic living polymer and successive anionic polymerization of methacrylates (RMAs) or radical polymerization of RMAs, acrylonitrile (AN), and styrene (St). Living polytetrahydrofuran (poly-THF) was prepared by cationic polymerization of tetrahydrofuran (THF), whose propagation end was reduced by samarium(II) iodide (SmI2). Anionic polymerizations of RMAs were conducted by addition of the monomers to the reduced poly-THF to obtain poly(THF-b-RMAs). On the other hand, the 2-bromoisobutyrate group, which can act as an initiator of radical polymerization, was introduced to the cationic propagating end of poly-THF by adding sodium 2-bromoisobutyrate. Block copolymers were synthesized by living radical polymerization of RMAs, St, or AN using the 2-bromoisobutyrate-capped poly-THF as a macroinitiator and copper(I) bromide (CuBr) as a catalyst. [ABSTRACT FROM AUTHOR]

Photoinduced electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerization of acrylonitrile (AN) in miniemulsion was reported. PET-RAFT polymerization of acrylonitrile (AN) was successfully accomplished with 4-cyanopentanoic acid dithiobenzoate (CPADB) as chain transfer agent (CTA), sodium dodecyl sulfate (SDS) as emulsifier, hexadecane (HD) as co-stabilizer and TiO2 as photocatalyst at 25 °C. The linear first-order kinetic plots were observed in miniemulsion with different amounts of SDS. Excellent temporal control was demonstrated by switching between ON/OFF states multiple times, and the prepared PAN macro-CTA was used successfully to perform the chain extension experiments, indicating high retention of chain end functionality. Furthermore, the obtained PAN was amidoximated with NH2OH·HCl. The Cd2+ was extracted with amidoxime (–C(NH2)=NOH) from aqueous solutions. The maximum adsorption of 98.6% Cd2+ with 400 mg of the adsorbent was observed at pH 6.0 and an initial Cd2+concentration of 4 mmol/L. [ABSTRACT FROM AUTHOR]

In this work, we examined the synthesis of novel block (co)polymers by mechanistic transformation through anionic, cationic, and radical living polymerizations using terminal carbon–halogen bond as the dormant species. First, the direct halogenation of growing species in the living anionic polymerization of styrene was examined with CCl4 to form a carbon–halogen terminal, which can be employed as the dormant species for either living cationic or radical polymerization. The mechanistic transformation was then performed from living anionic polymerization into living cationic or radical polymerization using the obtained polymers as the macroinitiator with the SnCl4/n‐Bu4NCl or RuCp*Cl(PPh3)/Et3N initiating system, respectively. Finally, the combination of all the polymerizations allowed the synthesis block copolymers including unprecedented gradient block copolymers composed of styrene and p‐methylstyrene. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 465–473 The direct mechanistic transformation during "controlled"/living polymerizations of styrene derivatives was accomplished through anionic, cationic, and radical growing active species via terminal carbon–halogen bond. The terminal chlorination in the anionic polymerization proceeded quantitatively under an appropriate condition, which consequently produced a macroinitiator for living cationic and radical polymerizations. The transformation allowed the synthesis of novel block copolymers including gradient block copolymers composed of styrene and p‐methylstyrene. [ABSTRACT FROM AUTHOR]

In this article, photoinduced electron transfer–reversible addition–fragmentation chain transfer (PET‐RAFT) polymerization of methyl methacrylate (MMA) was investigated at moderate temperature in N,N‐dimethylformamide with ZnO as photocatalyst. The polymerization has a living characteristic: a linear increase in molecular weight (Mn,GPC), good agreement between experimental (Mn,GPC) and theoretical molecular weights (Mn,th), a decrease in molecular weight distribution (Mw/Mn) with increasing monomer conversion, and chain extension. The PET‐RAFT polymerization of MMA can be regulated by switching "ON" and "OFF" the light. [ABSTRACT FROM AUTHOR]

The reversible addition‐fragmentation chain transfer polymerization of diisopropyl fumarate (DiPF) was carried out using ethyl 2‐[[(dodecylthio)thioxymethyl]thio]‐2‐methylpropionate (T1) and 1,1′‐(1,2‐ethanediyl) bis[2‐[[(dodecylthio)thioxymethyl]thio]‐2‐methylpropionate] (T2) as the monofunctional and difunctional chain transfer agents (CTAs) to synthesize poly(diisopropyl fumarate) (PDiPF) with a rigid chain conformation. The obtained PDiPF had a well‐controlled molecular weight, molecular weight distribution, and structure of the chain ends. Size exclusion chromatography and NMR measurements revealed an excellent introduction efficiency (84–98%) of the terminal trithiocarbonate group into the polymer chain end. They were available as the monofunctional and difunctional macro‐CTAs to synthesize the AB and ABA block copolymers, respectively. While the well‐controlled block copolymers were solely obtained by the polymerization of 2‐ethylhexyl acrylate as the second monomer in the presence of PDiPF as the macro‐CTA, the block copolymerization of DiPF using poly(2‐ethylhexyl acrylate) as the macro‐CTA failed. The trithiocarbonate group at the chain end was completely removed by the reaction with n‐butylamine and it was valid for the improvement of the coloration and other optical properties of the transparent polymers. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 2584–2594 The reversible addition‐fragmentation chain transfer (RAFT) polymerization of diisopropyl fumarate was carried out using mono‐ and difunctional chain transfer agents (T1 and T2) to synthesize poly(diisopropyl fumarate) (PDiPF) with a well‐defined molecular weight, molecular weight distribution, and structure of the chain ends. They were available for the synthesis of the AB and ABA block copolymers with poly(2‐ethylhexyl acrylate) (P2EHA). The trithiocarbonate group at the chain end was removable by reduction to provide highly transparent polymers. [ABSTRACT FROM AUTHOR]

The resveratrol imprinted polymer prepared by RAFT reagent was used for separation and enrichment of real sample.Resveratrol imprinted polymer was synthesized by a reversible addition-fragmentation chain transfer(RAFT)polymerization method, combining molecular imprinting with living radical polymerization techniques, using the dibenzyltrithiocarbonate(DBTTC)as reversible RAFT reagent, resveratrol as the imprinted compound, and acrylamide(AM)as functional monomers,ethyleneglycoldim ethacrylate(EDMA)as cross-linker and 2,2-azob isisobuty ronitrile(AIBN)as initiator. The effects of the ratio of monomer to crosslinker, initiator dosage, solvent dosage, reaction time and reaction temperature on the morphology, recognition ability and separation efficiency of imprinted polymers were investigated by scanning electron microscopy(SEM), infrared spectroscopy(IR)and high performance liquid chromatography(HPLC). Results indicated that the polymer was selective for resveratrol with a combined amount(Q)of 1 283μg/g. Living radical polymerization method was applied to synthesize the resveratrol imprinted polymer with a better morphology and a higher adsorption efficiency for the target. [ABSTRACT FROM AUTHOR]

Copyright of Kobunshi Ronbunshu is the property of Society of Polymer Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Ab initio emulsion polymerization of methyl methacrylate (MMA) using a water‐soluble organotellurium chain transfer agent in the presence of the surfactant Brij 98 in water is reported. Polymerization proceeded under both thermal and visible light‐irradiation conditions, giving poly(methyl methacrylate) (PMMA) with controlled molecular weight and low dispersity (Đ<1.5). Despite the formation of an opaque latex, the photoactivation of the organotellurium dormant species took place efficiently, as demonstrated by the quantitative monomer conversion and temporal control. Control of polymer particle size (PDI<0.030) was also achieved using a semi‐batch monomer addition process. The PMMA polymer in the particles retained high end‐group fidelity and was successfully used for the synthesis of block copolymers. [ABSTRACT FROM AUTHOR]

ABSTRACT The benzaldehyde derivatives, such as 2,4-dimethoxy benzaldehyde (PC1) and p-anisaldehyde (PC2), were successfully used as photoredox catalysts (PCs) in combination with typical RAFT agent 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid (CTP) for the controlled photoinduced electron transfer RAFT polymerization (PET-RAFT) of methyl methacrylate (MMA) and benzyl methacrylate (BnMA) at room temperature. The kinetics of the polymerizations showed first order with respect to monomer conversions. Besides, the average number molecular weights ( Mn) of the produced polymers increased linearly with the monomer conversions and kept relatively narrow polydispersity (PDI = Mw /Mn). For example, the Mn of PMMA increased from about 3400 to 17,300 g mol−1 with the increasing in monomer conversion from 11% to 85%, and the PDI maintained around 1.36. The living features of polymerizations with the PC1 and PC2 as catalysts have also been further supported by chain extension and synthesis of PMMA- b-PBnMA diblock copolymer. As a result, the simplicity and efficiency of benzaldehyde derivatives catalyzed PET-RAFT polymerization have been demonstrated under mild conditions. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 229-236 [ABSTRACT FROM AUTHOR]

The work aims to interpret the phase behavior of multi-polymers in super critical CO 2 via a spatially dependent structural parameter, the monomer sequence distribution, rather than traditional statistical factors. Well-defined statistical copolymers based on three CO 2 -philic monomers, vinyl acetate, vinyl butyrate and vinyl butyl ether, were synthesized with reversible addition-fragmentation chain transfer free-radical polymerization by combining their kinetic behaviors and pairwise reactivity ratios into the Alfrey–Goldfinger–Skeist model. The corresponding cloud point pressures become nonlinear with the polymer composition and possess upper critical solution pressure behavior. Additionally, their diad and triad monomer sequence distributions were calculated by simple theoretical arithmetic. While analyzing the cloud point pressure measurements, we found that both the differences in composition and symmetrical structure of the monomer triads could impact the CO 2 -philicity of triads, which were close to the properties of the products, and thus, the variations in the triad sequence distribution could reasonably predict the phase behavior of the products. [ABSTRACT FROM AUTHOR]

Amphiphilic random copolyacrylamides bearing hydrophilic poly(ethylene glycol) (PEG) and hydrophobic dodecyl pendants induce precision self-assembly to produce quite small uniform and/or necklace micelles (≈10 nm) in water. The size, structure, and thermoresponsive properties of the micelles are controlled by the primary structure (composition and chain length) of the copolymers. For this, random copolymers with different composition, chain length, and molecular weight distribution are synthesized by iron-catalyzed living or free radical copolymerization of PEG acrylamide and dodecyl acrylamide (DAAm). The copolymers with controlled molecular weight (degree of polymerization: ≈40) intermolecularly self-assemble and/or self-fold to form uniform (multichain or unimer) micelles in water; the size increases with increasing hydrophobic DAAm content (19-57 mol%: Mw = 43 900-191 000). In contrast, random copolymers with relatively small DAAm content (<35 mol%) and broad molecular weight distribution provide both uniform and necklace micelles in water. [ABSTRACT FROM AUTHOR]

ABSTRACT Herein, we clarified the ring-expansion cationic polymerization with a cyclic hemiacetal ester (HAE)-based initiator was versatile in terms of applicable vinyl ether monomers. Although there was a risk that higher reactive vinyl ethers may incur β-H elimination of the HAE-based cyclic dormant species to irreversibly give linear chains, the polymerizations were controlled to give corresponding cyclic polymers from various alkyl vinyl ethers of different reactivities. Functional vinyl ether monomers were also available, and for instance a vinyl ether monomer carrying an initiator moiety for metal-catalyzed living radical polymerization in the pendant allowed construction of ring-linear graft copolymers through the grafting-from approach. Furthermore, ring-based gel was prepared via the addition of divinyl ether at the end of the ring-expansion polymerization, where multi HAE bonds cyclic polymers or fused rings were crosslinked with each other. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3082-3089 [ABSTRACT FROM AUTHOR]

Different types of the styrene − methyl methacrylate −acrylonitrile terpolymers were synthesized according to the recently proposed concept of the living nitroxide-mediated terpolymerization. Random azeotropic and gradient terpolymers were prepared using the living TEMPO-mediated polymerization. Block random terpolymer was obtained via the living terpolymerization initiated by macro-alkoxyamine polystyrene-SG1. In all systems, terpolymerization proceeds in the living manner even in the presence of TEMPO. Upon complete polymerization at high conversions of monomers, the molecular weight of terpolymers linearly increases with the monomer conversion. The resultant terpolymers were characterized by the methods of turbidimetric titration, GPC, DSC, and TGA, and their characteristics were compared with their non-living analogs synthesized by the conventional radical polymerization. The effect of the macromolecular structure on the thermal stability of the terpolymers was studied. [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]

Copyright of Kobunshi Ronbunshu is the property of Society of Polymer Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A low-intensity (6 W) light-emitting diode (LED) effectively activated an organotellurium chain transfer agent and the dormant species, promoting well-controlled radical polymerization. The use of the LED provided many advantages over the previously reported high-intensity Hg lamp, including high energy efficiency during the polymerization, and easy availability of the low-cost light source. Structurally well-defined poly(methyl methacrylate), poly(methyl acrylate), and polystyrene, with narrow molecular weight distributions, were synthesized under LED irradiation with or without a neutral density filter.