Magnetic field effects on the copolymerization of water‐soluble and ionic monomers

The effect of magnetic field (MF) on the radical copolymerization of a series of water‐soluble and ionic monomers is presented including acrylamide (AM), acrylic acid (AA), its ionized form acrylate (A^?), and diallyldimethylammonium chloride (DADMAC). The following combinations have been studied: AM/AA, AM/A^?, AM/DADMAC, and AA/DADMAC. In addition to the MF, strong electrostatic interactions are present for the majority of monomer combinations and conditions. Although the monomer consumption rate (R_p) increased up to 65% applying a MF of 0.1 Tesla, the composition of the resulting copolymers was not affected under such conditions. Despite this increase of R_p by MF, the electrostatic repulsion between ionic monomers and charged growing radicals dominates R_p and governs the copolymer composition with and without MF. The order of the experimentally obtained reactivity ratios reflects the extent of electrostatic interaction: r_AM/AA (1.41) < r (3.10) < r_AA/DADMAC (4.25) < r_AM/DADMAC (6.95) and r_AA/AM (2.20) > r_DADMAC/AA (0.25) > r (0.17) > r_DADMAC/AM (0.03). Overall, weak MF offers to reduce the production time without modifying the product composition. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 373–383, 2009     

二乙基二烯丙基氯化铵与丙烯酰胺、丙烯酸共聚竞聚率

二乙基二烯丙基氯化铵;丙烯酰胺;丙烯酸;共聚合;竞聚率     

Copolymerization of acrylamide with allyl-acrylate quaternary ammonium monomers

A series of copolymers of N,N-morpholine-N-2-(ethoxycarbonyl)allyl allyl ammonium chloride, N,N-morpholine-N-2-(ethoxycarbonyl)allyl allyl ammonium bromide, N,N-piperidyl-N-2-(ethoxycarbonyl)allyl allyl ammonium chloride, N,N-morpholine-N-2-(t-butoxycarbonyl)allyl allyl ammonium bromide and diallyldimethylammonium chloride (DADMAC) with acrylamide (AAm) were prepared in water at 50-56°C using 2,2'-azo-bis(2-amidinopropane)dihydrochloride (V-50). The ethyl ester monomers showed high cyclization efficiencies during copolymerizations. The tert-butyl ester derivatives showed high cross-linking tendencies. The molar fractions of allyl-acrylate monomers in the AAm: allyl-acrylate copolymers were higher than the one of DADMAC in the AAm:DADMAC copolymers. The intrinsic viscosities of the copolymers measured in 0.09 M NaCl ranged from 2.5 to 7.5 dL/g.     

Propagation rate coefficients of isobornyl acrylate,tert‐butyl acrylate and 1‐ethoxyethyl acrylate: A high frequency PLP‐SEC study

Pulsed laser polymerization (PLP) coupled to size exclusion chromatography (SEC) is considered to be the most accurate and reliable technique for the determination of absolute propagation rate coefficients, k_p. Herein, k_p data as a function of temperature were determined via PLP‐SEC for three acrylate monomers that are of particular synthetic interest (e.g., for the generation of amphiphilic block copolymers). The high‐T_g monomer isobornyl acrylate (iBoA) as well as the precursor monomers for the synthesis of hydrophilic poly(acrylic acid), tert‐butyl acrylate (tBuA), and 1‐ethoxyethyl acrylate (EEA) were investigated with respect to their propagation rate coefficient in a wide temperature range. By application of a 500 Hz laser repetition rate, data could be obtained up to a temperature of 80 °C. To arrive at absolute values for k_p, the Mark‐Houwink parameters of the polymers have been determined via on‐line light scattering and viscosimetry measurements. These read: K = 5.00 × 10⁵ dL g⁻¹, a = 0.75 (piBoA), K = 19.7 × 10⁵ dL g⁻¹, a = 0.66 (ptBA) and K = 1.53 × 10⁵ dL g⁻¹, a = 0.85 (pEEA). The bulky iBoA monomer shows the lowest propagation rate coefficient among the three monomers, while EEA is the fastest. The activation energies and Arrhenius factors read: (iBoA): log(A/L mol⁻¹ s⁻¹) = 7.05 and E_A = 17.0 kJ mol⁻¹; (tBuA): log(A/L mol⁻¹ s⁻¹) = 7.28 and E_A = 17.5 kJ mol⁻¹ and (EEA): log(A/L mol⁻¹ s⁻¹) = 6.80 and E_A = 13.8 kJ mol⁻¹. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 6641–6654, 2009     

Polymerization of the 12-methacryloyloxydodecanoic acid and a corresponding phospholipid in monolayers at the liquid/gas interfaces

The following surface-active monomers with methacrylic group at the end of hydrophobic tail: 12-methacryloyloxydodecanoic acid (12-MAODA) and 12-(methacryloyloxydodecanoyl)-glycerophosphatidylcholine 12-MAODPC) were synthesized and investigated. Both monomers are forming monolayers at the liquid/gas interfaces with liquid-expanded and liquid-condensed states at low and high surface pressures, respectively. These monomers have been polymerized in the monolayers just by soft UV-irradiation (254 nm). Dependences of polymerization rate vs. surface pressure for both monomers have maxima (3.33^*10⁻⁴ s⁻¹ for 12-MAODPC and 4.89^*10⁻⁴ s⁻¹ for 12-MAODA) at about 8–10 mN/m. The higher polymerization rate of 12-MAODA polymerization as compared to 12-MAODPC is due to the more dense packing of the acid molecules in monolayers as compared to the lipid. Areas per monomer unit in the obtained polymeric monolayers are much smaller than those for the monomer one. The collapse pressures increase after monomer polymerization that evidences the increase of the monolayer stability in case of polymer as compared to monomer.     

聚烯丙基氯化铵模板对AM/AA共聚物结构的影响

采用IR,1H-NMR和13C-NMR研究了聚烯丙基氯化铵(PAAC)模板对丙烯酰胺(AM)/丙烯酸(AA)共聚产物结构的影响,发现这种模板对共聚物P(AM/AA)序列结构和分子量有重要影响.由于共聚合体系中AA单体在PAAC模板聚合物上预组装,使得模板体系共聚物比无模板体系共聚物的AA和AM序列长度显著增加.这种类似多嵌段结构得到pKa′测定的进一步验证.另外模板分子量大小,模板和AA单体摩尔比,AM和AA摩尔比对共聚物结构的影响也进行了研究.应当指出这种模板聚合产物分离模板后仍有少量不能分离掉的PAAC聚合物存在.     

Synthesis of hyperbranched polymers from vegetable oil based monomers via ozonolysis pathway

In this work, a variety of hyperbranched polymers (HBPs), such as hyperbranched polycarbonates, polyesters, polyurethanes and polyacetals, was successfully synthesized from castor oil and soybean oil based monomers via a A₂ + B₃ polycondensation. First, B₃ monomer triols (TriOL), trialdehydes (TriAD), and tricarboxylic acids (TriAC) were obtained by ozonolysis of castor oil and soybean oil with following reductive or oxidative treatment. Their structures were characterized by ¹H NMR and ATR‐FTIR spectroscopy as well as electrospray ionization‐Time of Flight‐mass spectrometry. These trifunctional B₃ monomers were applied in the preparation of HBPs. The resulting HBPs had number averaged molar mass (M_n) up to 9400 g/mol and weight averaged molar mass (M_w) up to 40,000 g/mol. Through adjusting the initial molar ratio of A₂ to B₃ monomers, hydroxyl terminated (from TriOL monomers) or carboxylic acid (from TriAC monomers) terminated HBPs could be obtained. All the HBPs were characterized by ¹H NMR, size exclusion chromatography, and DSC. These HBPs are potential candidates for the synthesis of cross‐linked polymeric materials or in biomedical applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2104–2114     

A computational and experimental investigation of the interaction between the template molecule and the functional monomer used in the molecularly imprinted polymer

A computational approach to screening monomer for preparing molecularly imprinted polymer (MIP) was proposed, using the binding energy, ΔE, of a template molecule and a monomer as a measure of their interaction. For a specified template molecule, a monomer of higher ΔE is suitable for preparing the MIP. To examine the validity of this approach, theophylline (THO) was chosen as the template molecule and methacrylic acid (MAA), acrylamide (AA) and 2-(trifluoromethyl)acrylic acid (TFMAA) were as the functional monomers, respectively. Density functional theory (DFT) at B3LYP/6-31+G**//B3LYP/3-21G level was used to calculate ΔE. It was shown that TFMAA gave the largest ΔE while AA gave the smallest. The details of the interaction between the THO with these monomers were also given by this computing approach. The adsorption of THO on the MIP synthesized using different monomers was studied. The MIP synthesized using TFMAA as monomer showed the highest selectivity to THO while the MIP from AA gave the lowest, as predicted from the ΔE calculation. ¹H NMR spectroscopy showed that, compared to MAA and AA, a stronger H-bond interaction is formed between TFMAA and THO. FT-IR analysis of the MIPs prepared using these three monomers confirmed the existence of CO and OH groups, which forms H-bond with THO. The results described above have given an insight into the interaction between THO and the monomers, and shown the use of ΔE to facilitate the selection of monomers for the synthesis of MIP.     

Cationic Lanthanide Luminescent Copolymer: Design,Synthesis and Interaction with DNA

Polymerizable rare earth complex Eu(AA)₃Phen was synthesized by complexion of europium ion, acrylic acid (AA), and 1,10-phenanthroline (Phen). The structure and fluorescence properties of the complex were studied by elemental analysis, ¹H-NMR spectroscopy, and fluorescence spectroscopy. Eu-containing copolymer poly(PEGMA-co-MMA-co-METAC-co-Eu(AA)₃Phen) (PPMMEu) was then synthesized by free radical copolymerization of Eu(AA)₃Phen and other functional monomers including poly(ethylene glycol) methyl ether methacrylate (PEGMA) and [2-(Methacryloyloxy) ethyl] trimethylammonium chloride (METAC). ¹H-NMR spectroscopy and fluorescence spectroscopy were used to characterize the copolymer and the interactions between the copolymer and DNA was investigated by TEM, fluorescence spectroscopy, and agarose gel electrophoresis. The desired luminescent cationic copolymer was successfully obtained. The copolymer can form micelles in water solution and can efficiently bind to DNA molecules through electrostatic interaction. The results suggest the potential use of PPMMEu in bioprobes and gene vectors.     

Reactivity Ratios of Diethyldiallylammonium Chloride with Acrylamide or Acrylic Acid

The compositions of copolymers of diethyldiallylammonium chloride (DEDAAC) with acrylamide (AM), acrylic acid (AA) or sodium acrylic acid (NaAA) at low conversion were determined by elemental analysis, and the reactivity ratios of monomers in copolymerization were obtained by Kelen-Tudos method. The results showed that the reactivity ratios rDE and rAM are 0.31 and 5.27 for DEDAAC with AM, rDE and rAA are 0.28 and 5.15 for DEDAAC with AA, and rDE and rNaAA are 0.40 and 3.97 for DEDAAC with NaAA, respectively. The copolymerizations for DEDAAC with AM, AA or NaAA are non-ideal copolymerization and the products are random copolymers.     

Gelation in the Copolymerization of Diallyldimethylammonium Chloride with Acrylamide

Diallyldimethylammonium chloride (DADMAC) was free-radical copolymerized with acrylamide (AA) in water at a total monomer concentration of 4 mol/L and 40°C with different monomer feed compositions. Gelation occurred only for 20/80 DADMAC/AA monomer feed although crosslinking was observed for all monomer feed compositions. The gel point was at 51% conversion, and the swelling ratios of the resulting gels were quite high, from 1400 to 700. Addition of 2‐propanol as a chain‐transfer reagent reduced crosslinking and prevented gelation. These results are mechanistically discussed in connection with the cyclopolymerizability of DADMAC, and significant allylic hydrogen abstraction by the growing polymer radical characteristic of allyl polymerization is proposed.     

Synthesis and kinetics of polymerization of hydrophilic monomers: 2,3-dihydroxypropylacrylate and 2,3-dihydroxypropylmethacrylate

Unsaturated monomers containing none, one, or two hydroxyl groups were obtained by the reaction of glycerol (1,2,3-trihydroxypropane) with acrylic and methacrylic chloride. The experimental values of the mole fractions of the different monomers were compared with those theoretically obtained by considering different mechanisms involving two or seven kinetic constants. Agreement between the theoretical and experimental results could only be achieved by assuming that the reactivity of the hydroxyl groups changed with the presence of the substituents. The investigation of the radical polymerizations 2,3-dihydroxypropylacrylate (GA) and 2,3-dihydroxypro- pylmethacrylate (GM) was carried out at several temperatures in water–dioxane solutions. Ultraviolet spectroscopic techniques were used to determine the kinetic constants, and the results were compared with those obtained in the same conditions for methyl acrylate, methyl methacrylate, 2-hydroxyethylacrylate, and 2-hydroxyethylmethacrylate. The values of the ratio k_p/k_t^1/2 for the methacrylic monomer GM were higher than 0.5 L^1/2 mol^−1/2 s^−1/2 at temperatures between 50 and 65 °C. These values exceeded 2 L^1/2 mol^−1/2 s^−1/2 for the acrylic monomer GA, perhaps the highest values reported for this kind of monomer. Electron paramagnetic resonance spectroscopy was also used to study the polymerization of GM. All the polymers were soluble in the reaction mixture until very high conversions, and the gel effect was never detected at monomer concentrations equal to or lower than 1 mol L⁻¹. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1843–1853, 2001     

Cyclocopolymerization of allyl‐acrylate quaternary ammonium salts with diallyldimethylammonium chloride

A series of copolymers of N,N‐dialkyl‐N‐2‐(methoxycarbonyl)allyl allyl ammonium chloride, N,N‐dialkyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride, and N,N‐dialkyl‐N‐2‐(t‐butoxycarbonyl)allyl allyl ammonium bromide with diallyldimethylammonium chloride (DADMAC) were prepared in water at 60 °C with 2,2′‐azo‐bis(2‐amidinopropane)dihydrochloride. A strong effect of ester substituents on cyclopolymerization was observed. The methyl and ethyl ester monomers showed high cyclization efficiencies during homopolymerizations and copolymerizations. Unexpectedly, the t‐butyl ester derivatives showed high crosslinking tendencies. Water‐soluble copolymers were obtained only with a decrease in the molar fraction of t‐butyl ester monomer below 30%. Relative reactivities of the allyl‐acrylate monomers in photopolymerizations were compared with the relative reactivity of DADMAC. Allyl‐acrylate monomers were much more reactive than DADMAC; the photopolymerization rate decreased in the following order: N,N‐morpholine‐N‐2‐(t‐butoxycarbonyl)allyl allyl ammonium bromide > N,N‐piperidyl‐N‐2‐(t‐butoxycarbonyl)allyl allyl ammonium bromide > N,N‐dibutyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride > N,N‐piperidyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride ∼ N,N‐morpholine‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride ∼ N,N‐piperidyl‐N‐2‐(methoxycarbonyl)allyl allyl ammonium chloride > N‐methyl‐N‐butyl‐N‐2‐(ethoxycarbonyl)allyl allyl ammonium chloride. Intrinsic viscosities of the polymers measured in 0.09 M NaCl ranged from 1.06 to 3.20 dL/g. The highest viscosities were obtained for copolymers of the t‐butyl ester monomers with piperidine and morpholine substituents. The copolymer of the t‐butyl ester with piperidine substituent and DADMAC was hydrolyzed in acid to give a polymer with zwitterionic character. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 640–649, 2001     

Hydrophobically modified polyelectrolytes III. Reactivity ratio determination of FX14/AA,LA/AA and SA/AA

The reactivity ratios of three hydrophobic monomers, FX14, LA and SA, to hydrophilic monomer, acrylic acid (AA), were determined. For the fluorocarbon containing hydrophobic monomer FX14, elemental analysis was adopted to obtain the relative content of FX14 to AA. For two hydrocarbon monomers, ¹³C NMR was used. FR, KT linear method and EVM nonlinear method were applied in calculating reactivity ratios. It is found that the reactivity of LA and SA is lower than that of AA, for solution polymerization in cyclohexane. Whereas FX14 is more reactive than AA in benzene. Finally, the distribution of small amounts of these hydrophobic monomers along the polymeric chain is discussed and a random sequence is confirmed     

60Co-initiated copolymerization of styrene with vinyl acetate

The kinetic behavior of the ⁶⁰Co-initiated copolymerization at 25°C of styrene with vinyl acetate at 1100 and 2000 rad/hr was studied. As in the case of thermal and photochemical copolymerizations of these monomers, the growing chains are particularly rich in styrene units, and the overall rate is affected by a diluent effect due to the vinyl acetate monomer. However, in the case of the radiation copolymerization, this effect is partially counterbalanced by an increase of the initiation rate with the vinyl acetate concentration; the polymerization rate curve shows a maximum at a vinyl acetate molar fraction of 0.25. This effect is due to the very different free radical yields of these two monomers. The experimental results may be understood on the basis of a kinetic scheme which involves an energy transfer process from the excited vinyl acetate molecules to the styrene monomer and a termination reaction of the growing chains by very short styrene radicals when the mixture is rich in vinyl acetate.     

Free radical copolymerization in the presence of lewis acids. I. Alternating copolymerization of vinyl acetate with acrylic acid in the presence of GeCl4 and BCl3

Alternating copolymers of vinyl acetate (VAC) and acrylic acid (AA) were obtained by free radical polymerization in the presence of GeCl₄ and BCl₃. For the GeCl₄ system, the reaction rate was proportional to [initiator]^1/2. Optimum rate was obtained when the molar ratio of the monomers was 1:1. The chain transfer agent CCl₄ had no effect on the reaction. By means of ultra-violet spectra analysis, it was concluded that both VAC and AA formed complexes with GeCl₄. ESR analysis gave us the information that salt complexed acrylic acid radical had greater cationic characteristics than uncomplexed radical. Thus the nature of alternation may be due to both complexed AA radical and activated monomer complexes.     

二甲基二烯丙基氯化铵/丙烯酸共聚凝胶的辐射合成与性质研究

采用γ辐射溶液聚合法合成了几种二甲基二烯丙基氯化铵 丙烯酸 (DADMAC AA)共聚凝胶 .实验结果表明单位体积溶液中二组分单体总摩尔数和丙烯酸 (AA)相对含量的增加使共聚凝胶力学强度明显增高 .在两种单体等摩尔比的情况下共聚体的凝胶含量随剂量增加而增加 ,且明显高于聚N ,N′ 二甲基二烯丙基氯化铵 (PolyDADMAC)凝胶 .体系中少量κ 卡拉胶 (KC)的加入可增强共聚凝胶韧性但对凝胶含量和强度影响甚微 .共聚凝胶溶胀性能测定结果表明DADMAC与AA摩尔比为 1∶2时凝胶溶胀比与体系pH值的关系呈现聚两性电解质性质 ,等电点pH值接近 4 5 .这种聚两性电解质性质在对铼Re(Ⅶ )离子浓集中也有所表现     

Polymerization of novel trifluorovinyl ethers: Insight into the mechanisms of termination and chain transfer

New trifluorovinyl ether polymers were synthesized with the view toward overcoming the high chemical and thermal stabilities commonly associated with fluoropolymers. Trifluorovinyl ether copolymers, with fluorinated pendant groups, have previously been prepared to overcome limitations in processibility. To further enhance solubility in common organic solvents and to improve processibility, we prepared three new trifluorovinyl ether monomers, having hydrocarbon ether pendant groups, for polymerization: 1-[2-(2-ethoxy ethoxy)ethoxy]-1,2,2-trifluoroethene (Et-TFVE), 1-[2-(2-t-butoxy ethoxy)ethoxy]-1,2,2-trifluoroethene (t-Bu-TFVE), and 1-(2-phenoxy ethoxy)-1,2,2-trifluoroethene (Ph-TFVE). Homopolymers of these three monomers were prepared by aqueous emulsion polymerization with the use of a redox initiator. Poly(Et-TFVE) and poly(Ph-TFVE) were prepared with a range of molar masses, the highest of which had weight average molar masses of 33,800 g mol⁻¹ and 59,000 g mol⁻¹, respectively. As a result of monomer reactivity and structure, the polymerization mechanism was complicated, resulting in β-scission termination/chain transfer for all three polymers and hydrogen abstraction chain transfer for poly(Et-TFVE) and poly(t-Bu-TFVE). To the best of our knowledge, this is the first example of hydrogen abstraction from the pendant group of the trifluorovinyl ether itself. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3301–3308, 1999     

Scandium‐Catalyzed Self‐Assisted Polar Co‐monomer Enchainment in Ethylene Polymerization

Direct coordinative copolymerization of ethylene with functionalized co‐monomers is a long‐sought‐after approach to introducing polyolefin functionality. However, functional‐group Lewis basicity typically depresses catalytic activity and co‐monomer incorporation. Finding alternatives to intensively studied group 4 d⁰ and late‐transition‐metal catalysts is crucial to addressing this long‐standing challenge. Shown herein is that mono‐ and binuclear organoscandium complexes with a borate cocatalyst are active for ethylene + amino olefin [AO; H₂C=CH(CH₂)_nNR₂] copolymerizations in the absence of a Lewis‐acidic masking reagent. Both activity (up to 4.2×10² kg mol⁻¹⋅h^−1> atm^−1>) and AO incorporation (up to 12 % at 0.2 m [AO]) are appreciable. Linker‐length‐dependent (n) AO incorporation and mechanistic probes support an unusual functional‐group‐assisted enchainment mechanism. Furthermore, the binuclear catalysts exhibit enhanced AO tolerance and enhanced long chain AO incorporation.     

High-Molecular-Weight Alternating Copolymers from Thermal Copolymerizations of N-Alkylcitraconimides with Styrene

Radical copolymerizations of eight N-alkylcitraconimides (1) and styrene (2) were carried out in the presence or absence of a radical initiator. Alternating copolymers with number-average molecular weights higher than 7 × 10⁵ were obtained from the thermal copolymerizations (monomer molar ratio = 1:1) in bulk at 60°C. The spontaneous copolymerization is considered to be by induced radicals produced via an intermediate Diels-Alder dimer and minary a contact-type charge transfer complex between N-alkylcitraconimide and styrene. Thermogravimetric analyses indicate the resulting copolymers have high thermal stabilities.