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This study established an environmentally friendly hydroxyl–yne click polymerization, which provides a new strategy for the preparation of color-tunable unconventional luminescent materials.

Compartmentalized micelles (CMs) are promising tailor-made soft matters that mimic natural designed structures and functions. Despite the structure of complex CMs, manipulating CM structures accessibly and reversibly remains elusive. Here, we report the fabrication of CMs via a generally valid noncovalent postmodification process. Starting from precursor micelles (PMs) based on one diblock copolymer, aromatic modification leads to the compartmentalization of PMs into well-defined spherical CMs. Control over compartment number, size and distribution in CMs, and segment distribution in their linear hierarchical assemblies is attained by simply tuning the postmodification degree and solvent composition. We also demonstrate the reversible transformation between PM and CMs during several heating-cooling cycles, which endows the micelles with potential in reversible functional transitions

Novel thermoresponsive nonconjugated fluorescent branched poly(ether amide)s with tunable LCST via t-BuP2-catalyzed oxa-Michael addition polymerization of N,N′-methylenebis(acrylamide) with triols.

Tadpole-like single-chain particle (TSCP) with a crosslinked PDMAEMA (poly(2-dimethylaminoethyl methacrylate)) chain as the head and a tethered POEGMA (oligo(ethylene glycol) monomethyl ether metha...

Tertiary amine-structured compounds containing stimulating response groups such as diethylaminoethyl isobutyrate and N-(2-(dimethylamino)ethyl)methyl, were synthesised by an acid chloride esterific...

Self-designed bis(4-vinylbenzyl)-oxalate (DBE) was synthesized successfully. The branched polystyrene was prepared by using an atom transfer radical polymerization method with copper bromide (CuBr)...

Here, we coined the term "clayene" for a single layer of clay and "few-layer clayene" for clays with 2-10 layers. Few-layer clayenes, which are Fe2+-rich and mica-type, were prepared hydrothermally at 200 °C and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM)/high-resolution transmission electron microscopy (HRTEM) to determine the crystalline phases and morphology, respectively. Chemical composition by energy-dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy confirmed the iron-rich mica composition, and the latter also revealed the presence of both Fe2+ and Fe3+. Mossbauer spectroscopy further confirmed the presence of Fe2+ and Fe3+ and their proportions in the mica-type few-layer clayenes. All of the synthesized mica-type few-layer clayenes except one exhibited high specific surface areas (SSAs) ranging from 94 to 149 m2/g as determined by N2 adsorption-desorption isotherms and the Brunauer-Emmett-Teller (BET) equation. The high surface areas are in conformity with the crystal sizes calculated from XRD peaks and also as revealed by HRTEM. Taking advantage of the interfacial reactions of the high surface area of few-layer clayenes, two potential applications of clayenes were demonstrated in materials and environmental fields.

The random-branched and the star-like branched polystyrenes were prepared by atom transfer radical polymerization (ATRP). Then the random-branched polystyrene and star-like polystyrene were blended...

In this research, we developed an efficient approach to prepare hyperbranched polymers at room temperature via phosphazene-base t-BuP2 catalyzed oxa-Michael addition polymerization from commercially available trifunctional hydroxyl and diacrylate monomers. The branching structure of the obtained polymers and the polymerization process were investigated by nuclear magnetic resonance (NMR) spectroscopy and triple-detection size-exclusion chromatography (TD-SEC) analysis. It was revealed that acrylic double bond terminated branched polymers with high molecular weights and high degrees of branching (Mw.MALLS > 2.8 × 105 g mol−1, DB ≥ 0.8) were produced by t-BuP2 catalyzed oxa-Michael addition polymerization of a trimethylolpropane (TMP) with a double molar 1,6-hexanediol diacrylate (HDDA) in DMF at room temperature, even at 0 °C. The study of the branching process showed that t-BuP2 catalyzed oxa-Michael addition branching polymerization is rapid, and that significant branched structures formed when the polymerization was performed at 3 min. Most importantly, the prepared branched polymers can be further post-functionalized via aza- or thio-Michael addition reactions, due to the polymers retaining the acrylic double bond functionality. This research provides a versatile and efficient method for the preparation of hyperbranched polymers from commercially available monomers, and it is feasible to prepare functional branched polymers for application in various fields.

The ring-forming behavior of polymers with an odd number of arms in highly dilute solutions has been studied using tri-arm polystyrene (PSt3) as a model through combining atom transfer radical polymerization (ATRP) and atom transfer radical coupling (ATRC) technologies. The star polymer, PSt3, with three arms and a central core was obtained by ATRP of styrene using a designed initiator with three active Br terminals and ester groups, followed by the Br terminal–Br terminal radical coupling of PSt3, which was implemented via intramolecular ATRC under high dilution conditions. A tadpole-shaped cyclic polymer (tadpole-PSt) was successfully prepared, proving that there no intermolecular side reactions that occur during the intramolecular ATRC of PSt3. Interestingly, the tadpole-PSt not only possesses a cyclic topology, but also contains a living chain, in contrast to other cyclic analogues that have been previously reported. Finally, the tadpole-PSt was used as a building block to construct a type of barbell polymer (barbell-PSt) by removing most of the solvent via vacuum distillation at the end of the intramolecular ATRC of PSt3. Size exclusion chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, 1H nuclear magnetic resonance spectroscopy and hydrolysis experiments proved that high-purity cyclic polymers (tadpole-PSt and barbell-PSt) were successfully prepared. The thermal properties of the cyclic and star polymers were analyzed using differential scanning calorimetry and thermogravimetric analysis. The results demonstrated that the formation of a cyclic topology makes a huge contribution to the increase in the glass transition temperature (Tg) and thermal stability of the polymer.

Phosphazene base, t-BuP2, was employed to catalyze the proton transfer polymerization (PTP) of 2-hydroxyethyl acrylate (HEA), and PTP was further combined with ring-opening polymerization (ROP) to exploit a new type of hybrid copolymerization. The studies on homopolymerization showed that t-BuP2 was a particularly efficient catalyst for the polymerization of HEA at room temperature, giving an excellent monomer conversion. Throughout the polymerization, transesterification reactions were unavoidable, which increased the randomness in the structures of the resulting polymers. The studies on copolymerization showed that t-BuP2 could simultaneously catalyze the hybrid copolymerization via the combination of PTP and ROP at 25 °C. During copolymerization, HEA not only provided hydroxyl groups to initiate the ROP of e-caprolactone (CL) but also participated in the polymerization as a monomer for PTP. The copolymer composition was approximately equal to the feed ratio, demonstrating the possibility to adjust the polymeric structure by simply changing the monomer feed ratio. This copolymerization reaction provides a simple method for synthesizing degradable functional copolymers from commercially available materials. Hence, it is important not only in polymer chemistry but also in environmental and biomedical engineering.

The anionic polymerization of methyl methacrylate (MMA) was carried out using phosphazene base t-BuP4 and ethyl acetate (EA) as the catalyst and the initiator, respectively. Gas chromatography (GC), size exclusion chromatography (SEC) measurements, and nuclear magnetic resonance (NMR) analyses were used to reveal the polymerization mechanism and to confirm the polymer structure. The results confirmed the proposed polymerization mechanism and the polymer structure, while the initiator efficiency was low. Meanwhile, the initiation by methoxy anion coming from hydrolysis of the ester bond in MMA was also observed. As a result, there is a marked deviation between the theoretical molecular weight and the measured molecular weight, and it is essential to carry out the polymerization at excessive dosage of t-BuP4 for preparing polymers with narrow molecular weight distribution.

We reported a facile and effective method for the preparation of highly branched polymers by combining the concepts of self-condensing vinyl polymerization (SCVP) and iodine transfer polymerization (ITP). This procedure used a chain transfer monomer synthesized in situ from a commercially available chloride compound, p-chloromethylstyrene (CMS). The efficiencies of the halogen exchange from the alkyl chloride (−CH2Cl) to the alkyl iodide (−CH2I) at room and high temperature were studied using CMS and benzyl chloride as model halogenated compounds. The structures of the resulting polymer and the branching behavior were analyzed by nuclear magnetic resonance (NMR) spectroscopy and size-exclusion chromatography (SEC) equipped with a differential refractive index detector, a multiangle laser light scattering detector, and a viscometer detector. The model study using small molecules revealed that −CH2Cl could efficiently halogen exchange with sodium iodide (NaI) at both room and high temperature. The model lin...

A typical multicyclic branched-topology polystyrene (c-BPS) with high molecular weight (30 K ≤ Mw MALLS ≤ 300 K g mol−1) and narrow dispersity (1.2 ≤ Đ ≤ 1.3) was efficiently synthesized by combining atom transfer radical polymerization (ATRP) and atom transfer radical coupling (ATRC) techniques. The topological constraints imposed by the presence of cyclic units and branch points had a marked influence on the entanglement behaviors of the polymer chains in solution. Therefore, c-BPS possesses the lowest loss modulus (G′′) and viscosity (η), the highest diffusion coefficient (D0), the largest mesh size (ξ) and the fastest terminal relaxation (TR), compared with branched and linear precursors.

The amide bond is one of the most pivotal functional groups in chemistry and biology. It is also the key component of proteins and widely present in synthetic materials. The majority of studies have focused on the formation of the amide group, but its postmodification has scarcely been investigated. Herein, we successfully develop the Michael additions of amide to acrylate, acrylamide, or propiolate in the presence of phosphazene base at room temperature. This amide Michael addition is much more efficient when the secondary amide instead of the primary amide is used under the same conditions. This reaction was applied to postfunctionalize poly(methyl acrylate-co-acrylamide), P(MA-co-Am), and it is shown that the amide groups of P(MA-co-Am) could be completely modified by N,N-dimethylacrylamide (DMA). Interestingly, the resulting copolymer exhibited tailorable fluorescence with emission wavelength ranging from 380 to 613 nm, which is a desired property for luminescent materials. Moreover, the emissions of the copolymer increased with increasing concentration in solution for all excitation wavelengths from 320 to 580 nm. Therefore, this work not only develops an efficient t-BuP4-catalyzed amide Michael addition but also offers a facile method for tunable multicolor photoluminescent polymers, which is expected to find a wide range of applications in many fields, such as in anticounterfeiting technology.

The radical polymerization of multivinyl monomers usually provides crosslinking polymers. It is a significant challenge how to control the structure of the polymers and to obtain soluble polymers in a high yield. In this work, the radical branching polymerizations of two asymmetrical divinyl monomers, allyl methacrylate (AMA) and furfuryl methacrylate (FMA), were investigated in detail. Both of the reactivity of the bonds and the weak transfer of isopropyl alcohol (IPA) were used to control the development of branching polymerizations and avoid gelation, without any other additives. As a result, the soluble branched PAMAs and PFMAs with extremely high molecular weights (106∼107) were successfully obtained. The branching factor (g’) of PAMA is very low (0.01–0.02), and that of PFMA is the higher (about 0.3) due to the weaker reactivity of furfuryl groups. Comparing with the results of using thiol chain transfer agent, the chain transfer of IPA had no obvious influence on the chain propagation at the early stage of the polymerizations, but could delay the gelation successfully at the later stage. Furthermore, the development of the branching structure could be studied in detail on the branching factor and rms radius since the gelation process was extended from several minutes to several hours.

Several branched polystyrenes were prepared by free radical emulsion polymerization in the presence of α-mercaptohexyl methacrylate (MHM) as the chain transfer monomers, potassium peroxodisulfate a...

This paper reports a new type of click chemistry via a phosphazene bases-catalyzed oxa-Michael addition of an alcohol to an acrylate. The studies on the reactions between small molecules showed that only 5 mol% phosphazene base, t-BuP2, could catalyze the reaction between the acrylate double bonds and a primary alcohol and drive the reaction to completion within a few minutes under solvent-free conditions at room temperature. Additionally, t-BuP2 was a particularly efficient catalyst for the oxa-Michael addition of secondary alcohols to acrylate double bonds under similar conditions. Moreover, applying this reaction to the synthesis of polymers could successfully afford degradable poly(ester-ether)s with excellent monomer conversions under mild conditions. Throughout the polymerization, transesterification reactions were unavoidable, which increased the randomness in the structures of the resulting polymers. Considering the remarkable features of this method, such as the ready availability of the alcohol substrates, this work provides a simple, easy, and versatile method for synthesizing degradable polymers from commercially available compounds and will be useful in polymer chemistry.

Aliphatic polyesters have been widely used in environmental and biomedical engineering, but a lack of functional groups limits their applications. Here, we reported a facile approach to synthesize vinyl functional polyester via the ring opening copolymerization of e-caprolactone (CL) and allyl glycidyl ether (AGE). NMR analysis confirmed the copolymeric structures and suggested that the copolymerization depended on the epoxide ring of AGE rather than vinyl group. The amount of AGE incorporated into the copolymers (FAGE) increased with the amount of epoxide monomer feed with a maximum incorporation of 16.7%. Increasing temperature helped AGE to incorporate into the copolymer, however, accompanying with lots amount of AGE homopolymers. The resulting copolymer was successfully post-functionalized by thiol-end click, epoxidation, and bromination reactions depending on the reactivity of pendent ally groups. This facile and efficient approach can be used to functionalize biodegradable polymers and synthesize some new polymers under mild conditions.

In this paper, we report radical polymerization in the presence of a peroxide monomer for the preparation of branched vinyl polymers. The peroxide monomer, tert-butyl peroxyacetate methacrylate (BPAMA), was designed and prepared in high purity from commercially available reagents via classic organic reactions. Triple-detection size-exclusion chromatography (TD-SEC) measurements, NMR analyses, and hydrolysis experiments were used to reveal the polymerization procedure and to confirm the branching structure of the prepared polymers. Branched polymers of styrene, methyl methacrylate (MMA), and vinyl acetate (VAc) were prepared under solvent-free conditions through radical polymerization in the presence of a peroxide monomer. Furthermore, radical polymerization in the presence of the peroxide monomer can be operated in a simple polymerization composition involving only the peroxide monomer BPAMA with MMA or VAc. The obtained branched polymers exhibited high molecular weights (Mw.MALLS > 106 g mol−1) and relatively narrow molecular weight distributions (2.5 ≤ PDI ≤ 6.8). Generally, radical polymerization in the presence of a peroxide monomer as the initiator and the branching agent can make the preparation of branched vinyl polymers almost equally as facile as the preparation of their linear analogs. This approach is applicable to a wide variety of monomers and can be performed with a simple polymerization composition in the bulk under moderate conditions compared with the reported strategies.

Here, we report the reversible complexation-mediated copolymerization (RCMcP) of vinyl and divinyl monomers for the synthesis of highly branched polymers. A conventional azo radical initiator, 2,2′-azobisisoheptonitrile (V65), a free-radical polymerization inhibitor (I2), and a highly reactive but inexpensive salt (NaI) were used to initiate and control the polymerization. The highly branched structures and process of branching were confirmed and thoroughly investigated. The reactivity of the vinyl groups incorporated into the copolymer was found to be similar to that of the monomers used in the RCMcP reaction. Large numbers of branched structures occurred when the conversion of MMA (conv.MMA) reached 56.6%, at which point the amount of pendant vinyl groups in the polymer reached a maximum value. The most significant branching occurred when the conv.MMA approached 90% because of intermolecular reactions between macromolecules. The polymerization reaction can also be performed without deoxygenation, with no obvious prolongation of induction. This work provides a simple, easy, and versatile method for the synthesis of highly branched polymers from commercially available compounds.

In this work, reversible complexation-mediated polymerization (RCMP) was modified to suit self-condensing vinyl polymerization (SCVP) aimed at the synthesis of highly branched polymers. For this purpose, two azo-containing pre-inimers with divinyl (DMACPO) or monovinyl (MACPO) substitution groups were synthesized and copolymerized with methyl methacrylate (MMA). The effects of the pre-inimer structure, the feed ratio, and oxygen on the monomer conversions and on the degree of branching of the obtained polymers were investigated thoroughly. The polymerization process and the branching behaviour were also studied in detail. The study of the DMACPO system revealed that the branched structures were synthesized from the beginning of the polymerization and that substantial branching occurred when the MMA conversion reached 54.7%. At the end of the polymerization, the MMA conversion was greater than 80%. The use of a small amount of additional azo initiator substantially increased the CC bond content among the inimers and the MMA conversion, affording polymers with a high degree of branching. The study of the MACPO system suggested that the monovinyl-functional inimer was much more effective than the divinyl-functional inimer, as the MMA conversion reached as high as 98.0% without inducing gelation. Moreover, the present synthesis could be conducted without additional deoxygenation irrespective of the pre-inimer employed. The current work provides a simple, easy, and versatile method for the synthesis of highly branched polymers from commercially available compounds and will facilitate the application of this method in various highly branched polymer syntheses.

Several inverse emulsions were prepared with different hydrophilic-lipophilic balance (HLB) values using different water/oil ratios, temperatures and monomer and emulsifier concentrations by uniform stirring for more than 30 min. The stability of inverse emulsion was characterized by centrifugal coefficient. The emulsion form, either oil/water (O/W) or water/oil (W/O) was characterized by optical microscope and conductivity measurements. The results showed that HLB value, water/oil ratio and temperature could have an effect on the emulsion stability and emulsion form. When the HLB value of emulsifier is about 8.4, the water to oil ratio is about 1:1 and the temperature is at about 25 °C, inverse emulsion in the form of water in oil (W/O) was found to be the most stable. Here, the stablilty of emulsions was studied in relation to temperature and we found that 25 °C (room temperature) is the best for obtaining the most stable inverse emulsion, which is also most suitable for the redox initiation in this system. In the present study, we showed that temperature has a significant influence on the structure morphology and stability of inverse emulsion and hence, it is necessary to select the appropriate reaction temperature for inverse emulsion polymerization. This is a novel result. A decrease of the content of hydroxyethyl methacrylate in aqueous solution with an increase of emulsifier concentration in emulsion was found to elevate the stability of inverse emulsion. The addition of trace electrolytes in the emulsion, however, led to greatly reduced stability of the inverse emulsion.

The aerobic radical polymerization of methyl methacrylate (MMA) in N,N-dimethylformamide (DMF) catalyzed by ppm-level complexes of copper(II), cobalt(II), or iron(III), leading to high-molecular-weight polymer (PMMA), was investigated in detail. No active radicals were formed, although DMF could reduce these complexes into their intermediates in the low oxidation state. Oligo(MMA peroxide)s formed in situ as multifunctional initiators decomposed into oxyl radicals to initiate polymerization under catalysis of these complexes. It was further revealed that these complexes undertook two-step O 2 activation. They initially catalyzed the interpolymerization of MMA with O 2 to afford oligo(MMA peroxide)s and then reduced oligo(MMA peroxide)s into alkyloxyl radicals to initiate polymerization of MMA in DMF, which played a triple role as the O 2 -rich solvent, the ligand, and the reducing agent.