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The SuFEx-based polycondensation between bisalkylsulfonyl fluorides (AA monomers) and bisphenol bis(t-butyldimethylsilyl) ethers (BB monomers) using [Ph3 P=N-PPh3 ]+ [HF2 ]- as the catalyst is described. The AA monomers were prepared via the highly reliable Michael addition of ethenesulfonyl fluoride and amines/anilines while the BB monomers were obtained from silylation of bisphenols by t-butyldimethylsilyl chloride. With these reactions, a remarkable diversity of monomeric building blocks was achieved by exploiting readily available amines, anilines, and bisphenols as starting materials. The SuFEx-based polysulfonate formation reaction exhibited excellent efficiency and functional group tolerance, producing polysulfonates with a variety of side chain functionalities in >99 % conversion within 10 min to 1 h. When bearing an orthogonal group on the side chain, the polysulfonates can be further functionalized via click-chemistry-based post-polymerization modification.

Abstract: Ionic liquids (ILs) are continuing as important media in which to effect various kinds of polymerizations, and it is particularly noteworthy that ionic polymerizations are being developed in IL solvents and that atom transfer radical polymerization (ATRP) catalysts are being attached to ILs to make them more easily recoverable in living polymerizations. In addition, the number of polymerizable ILs is steadily increasing, and ionic liquid polymers of polymerizable ionic liquid monomers have been produced as exotic polyelectrolytes. ILs are being used as plasticizers of various kinds of polymers and as key components in new classes of polymer gels. Polymers and inorganic substrates are being used to support ILs through covalent binding of the ILs, in which case the properties of the IL are modified to some extent, and polymer membranes and porous materials absorb ILs with concomitant changes in ionic conductivity and mobility. New applications of ILs include creating new classes of advanced materials, such as a new class of solvogels that are stimuli responsive and reversibly porate via pinned spinodal decomposition and the development of ILs derived from inorganic nanoparticle cores for use as new resin components for diverse materials and coatings applications. [Copyright &y& Elsevier]

Abstract: A series of soluble polyacrylates containing different azobenzene side chains have been synthesized via atom transfer radical polymerization (ATRP) technique, from which the side-chain nonlinear optical (NLO) polymers with controllable molecular weight and low polydispersity (1.1–1.4) have been obtained. The third-order NLO absorption and refraction coefficients were simultaneously determined by Z-scan technique. The polymerization activity of the azobenzene-containing acrylate monomers and the third-order NLO properties of the obtained polyacrylates were both dominated by the electronic effect of the different substituents in the azobenzene side chain. The results of Z-scan with and without an aperture showed that all the azobenzene-containing monomers and polymers have both nonlinear absorption and nonlinear refraction. The third-order NLO susceptibility (χ (3)) of all the azobenzene-containing samples under the laser irradiation is 1.0–5.0×10−11 esu. [Copyright &y& Elsevier]

A series of polyacrylates containing different substituted-azobenzene chromophores were synthesized and polymerized via atom transfer radical polymerization. Nonlinear optical homopolymers containing an azobenzene side chain, of controllable molecular mass and low polydispersity (1.1–1.4) were obtained. In addition, side-chain copolymers were prepared in which the composition of the copolymers was controlled by using different feed ratios of the azobenzene monomer and methyl methacrylate. The third-order nonlinear optical properties of azobenzene monomers and their polymers were measured using the degenerated four-wave mixing technique. Each of the polymers displayed a high χ (3) of about 10−11 esu and rapid response time in femto-second magnitude. The effect of substituents on the azobenzene group and the composition of the polymer chain on the third-order nonlinear optical properties of the polymers were investigated. [Copyright &y& Elsevier]

Thiol-functional polystyrene-CdS nanocomposites have been prepared via an in-situ method. The products were characterized in detail. The photoluminescence properties of products were also studied. The thiol fraction in thiol-functional polystyrene can be controlled by the copolymerization of styrene and 4-chloromethylstyrene. So, the CdS content in polymer and the photoluminescence properties of nanocomposites can be tuned up quantificationally. Results show that the fluorescence of nanocomposites depends on the CdS content. The charge-transfer mechanism of nanocomposites accords with ligand-to-metal charge-transfer (LMET) model. These nanocomposites can be used as potential optical materials. [ABSTRACT FROM AUTHOR]

Abstract: Microwave irradiation (MI) was applied to the atom transfer radical polymerization (ATRP) of azo-containing acrylates. The polymerization was greatly promoted and the reaction time was shortened from several days to about 1h. The polymerization was well-controlled within an incipient period but it was influenced by “hyperthermia effect” after a certain time. The functional polymers obtained under MI process have good third-order nonlinear optical (NLO) properties as those of polymers obtained under CH process. [Copyright &y& Elsevier]

Atom transfer radical polymerization (ATRP) of MMA was conducted using 2-(4-chloromethyl-phenyl)-benzoxazole as initiator, CuCl as catalyst, and PMDETA as ligand. The results show that the polymerization is a first order reaction with respect to monomer concentration. The polymerization displayed living character as evidenced by a liner increase of monomer weight with conversation and a relatively narrow distribution (Mn/Mw range from 1.30 to 1.45). The structure of PMMA was analyzed by 1H-NMR and proved the polymerization could be controlled to some degree. The optical property of the initiator was well preserved in the resulting PMMA, and the end-functionalized PMMA exhibited fluorescent emission at 360 nm whether in DMF solution or in film state. [ABSTRACT FROM AUTHOR]

Abstract: A polymeric copper complex PS–DCTACE–Cu(II) including cross-linked polystyrene as ligand, whose surface was modified by dicarbonyl tetraza-crown ether groups, was prepared and characterized. It was utilized as a heterogeneous catalyst for methyl methacrylate (MMA) polymerization in Na2SO3 aqueous solution at ambient temperature. The monomer conversion was high and reaction condition was mild. Moreover, the catalyst had good mechanical property and was very easy to be recycled from the reaction system. The polymerization mechanism was also proposed and confirmed by corresponding detections. The polymerization proceeded through a free radical way, in which the radicals were formed by the process of ‘chloridion leaving-hydrogen transfer’ in this PS–DCTACE–Cu(II)/Na2SO3/MMA system. [Copyright &y& Elsevier]

Abstract: Functionalized polystyrene (PSt) was synthesized utilizing atom transfer radical polymerization (ATRP), which was conducted by using 2-(4-chloromethyl-phenyl)-benzoxazole (CMPB) as initiator, CuCl/PMDETA as catalyst, and cyclohexanone as solvent. The mechanism of ATRP was proved by characterizing the structure of PSt via 1H NMR and preparing of PSt-b-PMMA block copolymer. The polymerization showed first order with respect to monomer concentration and relatively narrow polydispersity (M w/M n range from 1.30 to 1.50). Factors such as different reaction temperatures, mole ratio of monomer to initiator and so on, which can affect the ATRP system, were discussed in the paper. Moreover, CMPB showed high activity and could initiate styrene polymerization even at ambient temperature. The optical property of initiator was well preserved in the obtained PSt, and the end-functionalized PSt exhibited strong fluorescent emission at 351nm. [Copyright &y& Elsevier]

Abstract: Triphenylmethyl chloride (TPMCl) was employed for the first time as the initiator of atom transfer radical polymerization (ATRP) of styrene in the presence of CuCl/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) as catalyst and cyclohexanone as solvent. The kinetic plot was first-order with respect to monomer. A linear increase of number average molecular weight (M n) vs. monomer conversion was observed, and the molecular weight distribution (MWD) was relatively narrow (M w/M n =1.2–1.5). 1H NMR spectra revealed the ω-Cl group at the chain end. Another two initiators, benzyl chloride (BzCl) and diphenylmethyl chloride (DPMCl), were also employed in contrast with triphenylmethyl chloride to investigate the influence of phenyl numbers on the polymerization. [Copyright &y& Elsevier]

The atom transfer radical polymerization of styrene (St) in bulk using 1-(chloromethyl) naphthalene (1-CMN) as an initiator in the presence of CuCl N,N,N ,N , N -pentamethyldiethylenetriamine (PMDETA) was investigated at 125°C. The results showed that 1-CMN was an effective initiator with higher initiation efficiency in ATRP of St. The molecular weights of the obtained polystyrene (PS) increased linearly with monomer conversion and the corresponding polydispersity index of polymers remained relatively narrow (1.17-1.30), indicative of well controlled polymerization of St in the presence of 1-CMN CuCl PMDETA. The end functionalized PS with naphthalene-label exhibited fluorescence in N,N-dimethylformamide (DMF). [ABSTRACT FROM AUTHOR]

Atom transfer radical polymerization (ATRP) of styrene (St) proceeded using 5-chloromethyl-2-hydroxy-benzaldehyde as initiator, CuCl as catalyst, and N,N,N′,N′,N′-pentamethyldiethyltriamine (PMDETA) as ligand. The results show that the polymerization is a first order reaction with respect to monomer concentration. The polymerization displayed living character as evidenced by a liner increase of monomer weight with conversation and a relatively narrow distribution (Mn/Mw ranges from 1.25 to 1.50). The end structure of PSt was analyzed by 1H-NMR, and PSt initiated MMA to form block copolymer (PSt-b-PMMA), which also proved that the polymerization could be controlled. The effects of reaction temperature and monomer to initiator mole ratio on the polymerization displayed living character were discussed. [ABSTRACT FROM AUTHOR]

The homogeneous atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was successfully carried out under pulsed microwave irradiation (PMI), using N,N-dimethylformamide (DMF) as a solvent, with ethyl 2-bromobutyrate (EBB)/CuCl/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) as an initiating system. Plots of ln([M]0/[M]) vs. time and molecular weight with narrow dispersities, 1.1 < Mw/Mn < 1.5, vs. conversion showed a linear dependence. The dependences of the rate of polymerization on mole ratios of [MMA]0/[EBB]0/[CuCl]0/[PMDETA]0 and the concentrations of ligand were presented. In comparison with the identical ATRP of MMA under the conventional heating (CH), the apparent rate constant of polymerization (kpapp) under PMI was 5.3–12.8 times larger than that under CH, indicating a significant increase of the polymerization rate of homogeneous ATRP of MMA under PMI. [ABSTRACT FROM AUTHOR]

The influence of the presence of an inorganic carrier in the polymerization systems was investigated in this paper. Ten polymerization systems that contained different inorganic carriers such as Al2O3, SiO2 were studied. The ten polymerization systems are dibutyltin Maleate (DBTM) and allyl thiourea (AT), DBTM and stearic acid vinyl ester (SAVE), SAVE and maleic anhydride (MH), SAVE and acrylamide (AM), itaconic acid (IA) and AM, SAVE and IA, AM and MH, IA, sodium acrylate (AANa), AM. It was found that the activity of monomer can be changed in the presence of a carrier and furthermore, the different species of carrier influence the activity of same monomer differently in the polymerization. [ABSTRACT FROM AUTHOR]

Abstract: Atom transfer radical polymerization (ATRP) of MMA was conducted successfully at ambient temperature (25°C) using 2-bromomethyl-4,5-diphenyloxazole as initiator, CuBr/2,2′-bipyridine (BPY) as catalyst, and 1,4-Dioxane as solvent. Factors such as the reaction temperature, mole ratio of monomer and catalyst to initiator, solvent and so on, which can affect the ATRP system, were discussed in the paper. Chain extension was conducted using polymer as the macro-initiator which was characterized via 1H NMR. The optical property of initiator was well preserved in the obtained PMMA, and the end-functionalized PMMA exhibited obvious fluorescent emission at 367nm. [Copyright &y& Elsevier]

Abstract: The self-initiated atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in cyclohexanone (CHO) in the presence of CuCl2/N,N,N′,N″,N″-pentamethyldiethylenetriamine (PMDETA) is reported. The linear semilogarithmic plot of ln([M]0/[M]) vs time, the linear increase of number-average molecular weight (M n) with conversion, and rather narrow molecular weight distributions (MWDs) have been observed, which are in agreement of the characteristics of living/controlled polymerization. The NMR spectrum revealed the existence of terminal chlorine. The chain extension further proved the living characteristic. The polymerization can only be successful using CHO as the solvent, and is well controlled at the temperature as low as 50°C. The effects of ligand, solvent, temperature and monomer to catalyst ratio are all discussed. [Copyright &y& Elsevier]

Abstract: The pH-responsive amphiphilic copolymer poly(SDMA-co-OEGMA) (PSO) was prepared from the pH-sensitive hydrophobic monomer 2-styryl-1,3-dioxan-5-yl methacrylate (SDMA) and the hydrophilic monomer oligo(ethylene glycol) methyl ether methacrylate (OEGMA) by radical polymerization. Polymeric aggregates with about 130nm diameter were obtained by the self-assembly of PSO in neutral aqueous solution. The critical aggregation concentration of the copolymer was determined to be 6.5mg/L (1.2×10−7 M). Cinnamic aldehyde (CA) small molecules are broken away from PSO side chains after the hydrolysis of acid-labile cyclic acetal in cultured A375 human melanoma cells and further suppress the proliferation of this kind of tumor cells. Furthermore, the PSO aggregate was demonstrated to be a drug carrier for encapsulating Nile Red as model drug in in vitro testing. Based on the pH-responsive characteristic, the Nile Red molecules loaded in self-assembly process could be released from the aggregate inside cultured B16 mouse melanoma cells. [Copyright &y& Elsevier]

Abstract: A novel initiator containing proflavine derivative moiety, 3,6-dibromo-isobutyramide acridine (DIA), was synthesized and initiated the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). A water-soluble monomer, N,N-dimethylacrylamide (DMAA) was also initiated by DIA for comparison. The obtained fluorescent polymers, PMMA–DIA and PDMAA–DIA, were characterized by 1H NMR, GPC and TGA. The emission spectra of the fluorescent polymers exhibit obvious changes in color and fluorescence intensity along with pH varied in range of 3.0–9.0. In addition, the obtained polymers present good film-forming capacity and the films also have a high quantum yield and pH response. Both oil-soluble PMMA–DIA and water-soluble PDMAA–DIA have steady optical and chemical properties by containing proflavine moiety in the main chain. [Copyright &y& Elsevier]

Abstract: A novel functional monomer incorporating quinoline derivative moiety as the side group, 2-[4-(2,7,7-trimethyl-3-ethoxycarbonyl-5-oxo-1,4,5,6,7,8-hexhydricquinoline)phenoxyl] ethylmethacrylate (HQPEMA), was synthesized and polymerized utilizing atom transfer radical polymerization (ATRP) technique. 2-(4-Chloromethylphenyl)benzoxazole (CMPB) and CuCl/PMDETA were used as the initiator and catalyst, respectively. GPC, 1H NMR and fluorescent emission spectroscopy were conducted for characterization of polymers. The linear increase of number average molecular weight (M n) versus conversion and the relatively narrow molecular weight distribution (M w/M n) of the obtained polymers confirmed that ATRP of HQPEMA was carried out successfully. In addition, the fluorescence “structural self-quenching effect” was observed in the DMF solution of the monomer HQPEMA, which bearing both electron-donating chromophore group and electron-accepting Ce also found that the fluorescence properties of the newly obtained polymers containing quinoline chromophore depended on both the monomer concentration in solution and the polarity of solvents. The emission of the polymer film showed that the emission peak maxima of the polymer film shifted 50nm towards high wavelength with respect to the polymer in DMF solution due to the intermolecular or intramolecular interactions of the polymer chains. [Copyright &y& Elsevier]

Abstract: A series of fluorescent polymers with tunable di-color emission, P(NVS) n –NAPHs, were prepared via well-controlled atom transfer radical polymerization (ATRP). Each of the obtained polymers with different molecular weights has a composite emission spectrum comprising a blue component originated from the monomer, 1-(4-vinylstyryl)naphthalene (NVS), and a green component originated from the initiator, 2-(2,3-dihydro-2-(4-methoxyphenyl)-1,3-dioxo-1H-phenalen-7-ylamino)-ethyl-2-chloroacetate (NAPH). The intensity of the blue and green emission bands can be easily tuned by changing the polymer chain length. The blue emission part is enhanced with increasing the molecular weight of the fluorescent polymer in both DMF solution and film state. [Copyright &y& Elsevier]

The atom transfer radical polymerization (ATRP) of n-octyl acrylate (OA) was successfully carried out using ethyl-2-bromobutyrate as an initiator, and CuBr/2,2′-bipyridine (bpy) as a catalyst under microwave irradiation (MI) at 76.8 °C. The polymerization of n-octyl acrylate under MI showed linear first-order rate plots, a linear increase of the number-average molecular weight Mn with conversion, and low polydispersities, 1.1, where Mw is weight-average molecular weight. The ATRP of n-octyl acrylate is well controlled. Under the same experimental conditions, the apparent rate constant, kpapp, under MI is larger apparently than that under conventional heating. In addition, the effects of concentration of catalyst and other factors on polymerization are reported. [Copyright &y& Elsevier]

Emulsion polymerization of methyl methacrylate (MMA) under pulsed microwave irradiation (PMI) with higher peak pulse power was studied. The effects of various parameters of PMI on the polymerization were analyzed and compared with that under conventional heating (CH) process. The results were summarized, as compared with that under CH, as follows. The amount of initiator used to reach constant conversion reduced by 50% at the same polymerization time; at the same initiator concentration 0.15 and 0.2 wt.%, the polymerization rate increased by 131% and 163%, respectively. The molecular weight of polymer obtained was 1.1–2.0 times larger than that under CH; at the same irradiation energy, the conversion achieved using a lower pulse power was greater than that using a higher pulse power. There seemed to be a factor of the irradiation energy efficiency; in other words, for the monomer conversion, the irradiation energy of low pulse power had a higher efficiency. The conversion achieved using a 3.5 μs pulse width was almost the same as that using a 1.5 μs pulse width. The results indicated that PMI had a significant non-thermal effect on the emulsion polymerization of MMA so as to effectively enhance the polymerization rate. The glass transition temperature (Tg), the polydispersity index (PDI) and the regularity of the polymer obtained using two processes were similar, indicating that the physical properties and microstructure of the polymer were not modified by the use of microwaves. [Copyright &y& Elsevier]

Polymerization of methyl methacrylate was carried out in the presence of 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN). The results exhibit controlled polymerization characters: well-controlled molecular weight, narrow polydispersity (minimal value: 1.09), molecular weight linearly increasing with conversion and first-order kinetics of polymerization. The polymer can be used to synthesize methyl methacrylate–styrene copolymer with narrow polydispersity (minimal value: 1.22). The polymers were characterized by 1H NMR and GPC. The effect of molar ratio among MMA/CNDB/AIBN on polymerization was investigated. [Copyright &y& Elsevier]