Synthesis and radical polymerization of methacrylic monomers with crown ethers in the ester residue: 1,4,7,10-tetraoxacyclododecan-2-ylmethyl methacrylate (original) (raw)
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Atom transfer radical polymerization of 1-phenoxycarbonyl ethyl methacrylate monomer
European Polymer Journal, 2004
Atom transfer radical polymerization conditions with copper(I) bromide/2,2 0-bipyridine (Cu/2,2 0-bpy) as the catalyst system were employed for the homopolymerization and random copolymerization of 1-phenoxycarbonyl ethyl methacrylate (PCMA) with methyl methacrylate (MMA). Temperature studies indicated that the polymerizations occurred smoothly in bulk at 110°C. Poly(PCMA)(polydispersity index ¼ 1.27) homopolymer was characterized and then used as macroinitiator for increasing its molecular weight. The homopolymerization of PCMA was also carried out under free radical conditions using 2,2 0-azobisisobutyronitrile as an initiator. The monomer and polymers were characterized by FT-IR and 1 H and 13 C-NMR techniques. The glass transition temperatures, the solubility parameters and average-molecular weights of the polymers were determined. Thermal stabilities of the polymers were given as compared with each other by using TGA curves. Thermal degradation products of poly(PCMA)s obtained by ATRP and free radical polymerization were compared with each other by using 1 H-NMR technique.
Journal of Polymer Science Part A: Polymer Chemistry, 1995
The synthesis of unsaturated monomers containing one or more hydroxyl groups by reaction between polyalcohols (number of OH, n 2 2) and monoacid chlorides has been theoretically analyzed. The difficulties were shown involved in the preparation of these monomers with a high degree of purity even in the most favorable case of the completely substituted compound. The calculated mole fractions of the two monomers that can be obtained by reaction between neopentylglycol and methacryloyl chloride were compared with the experimental ones. Kinetic experiments of the polymerization of 3-hydroxyneopentyl methacrylate and 2-hydroxyethyl methacrylate were carried out at different temperatures in 1,4-dioxane for the former monomer and dioxane and absolute ethanol for the latter. Dilatometric techniques and nonlinear least-squares methods were used to obtain kinetic data and to determine the kinetic constants, respectively. In homogeneous solution the values of k,,/k:'' for the 3-hydroxyneopentyl methacrylate and 2-hydroxyethyl methacrylate were higher than those given for methyl methacrylate. The stereostructure of the polymers derived from 3-hydroxyneopentyl methacrylate and 2-hydroxyethyl methacrylate was determined by 13C-NMR spectroscopy and the molar fractions of tactic triads and dyads were calculated from different resonance signals. The polymers are predominantly syndiotactic and follow a Bernoullian distribution of tactic sequences. Finally, the glass transition temperatures of both polymers, determined calorimetrically, were 145 and 89"C, respectively. 0 1995 John Wiley & Sons, Inc.
Journal of Polymer Science Part A: Polymer Chemistry, 1999
The kinetic behavior of the free-radical polymerization of 2-hydroxy-4-Nmethacrylamidobenzoic acid (4-HMA) and 2-hydroxy-5-N-methacrylamidobenzoic acid (5-HMA) in a solution of N,N-dimethylformamide is described. The methacrylic monomers 4-HMA and 5-HMA were isomers in which the phenolic and carboxylic functional groups were in different positions on the side aromatic ring with respect to the methacrylamide group. Semiempirical (AM1 and PM3 treatments) and ab initio (6-31G**) quantum mechanical calculations indicated the existence of intramolecular H-bonding between the phenolic and carboxylic groups. These calculations also indicated a slightly higher reactivity of 4-HMA with respect to 5-HMA under the same experimental conditions as obtained from the frontier orbital interactions between the highest molecular orbital of the monomers and the singly occupied molecular orbital of the radical obtained by the reaction of a methyl radical with the corresponding monomer. Gravimetric study of the free-radical polymerization of 4-HMA and 5-HMA at several temperatures ranging from 50 to 150°C demonstrated this behavior. The kinetic results obtained and the average molecular weights of the polymers prepared at different temperatures indicated that the monomer 4-HMA had a slightly higher reactivity at low temperatures (50 -90°C), whereas at higher temperatures (120 -150°C ), the reactivity of both monomers became similar as a consequence of the "dead-end" radical polymerization.
Kinetic study of the radical polymerization behavior ofN-(1-phenylethylaminocarbonyl)methacrylamide
Journal of Polymer Science Part A: Polymer Chemistry, 2005
Polymerization of N-(1-phenylethylaminocarbonyl)methacrylamide (PEACMA) with dimethyl 2,2Ј-azobisisobutyrate (MAIB) was kinetically studied in dimethyl sulfoxide (DMSO). The overall activation energy of the polymerization was estimated to be 84 kJ/mol. The initial polymerization rate (R p) is given by R p ϭ k[MAIB] 0.6 [PEACMA] 0.9 at 60°C, being similar to that of the conventional radical polymerization. The polymerization system involved electron spin resonance (ESR) spectroscopically observable propagating poly(PEACMA) radical under the actual polymerization conditions. ESRdetermined rate constants of propagation and termination were 140 L/mol s and 3.4 ϫ 10 4 L/mol s at 60°C, respectively. The addition of LiCl accelerated the polymerization in N,N-dimethylformamide but did not in DMSO. The copolymerization of PEAC-MA(M 1) and styrene(M 2) with MAIB in DMSO at 60°C gave the following copolymerization parameters; r 1 ϭ 0.20, r 2 ϭ 0.51, Q 1 ϭ 0.59, and e 1 ϭ ϩ0.70.
Journal of Polymer Science Part A: Polymer Chemistry, 2004
Copolymerization and homopolymerization of benzyl methacrylate (BMA) and ethyl methacrylate (EMA) by the atom transfer radical polymerization method (ATRP) were performed at 90°C. ATRP of BMA was also carried out at 80, 100, and 110°C. The number-average molecular weight (M n) and polydispersities decreased with temperature. When BMA units increased in the copolymer system, the M n values and polydispersities decreased (1.63 Ͻ M w /M n Ͻ 1.13). The homopolymers and poly(BMAco-EMA) were characterized by Fourier transform infrared (FTIR), 1 H and 13 C NMR, and gel permeation chromatography (GPC) techniques. The compositions of the copolymers were calculated from 1 H NMR spectra. For the atom transfer radical copolymerization system, their monomer reactivity ratios were obtained by using the Kelen-Tü dös equation, as r 1 ϭ 0.812, r 2 ϭ 1.162 (r 1 is the monomer reactivity ratio of BMA). The initial decomposition temperatures of the resultant copolymers decrease with an increasing mol fraction of BMA, which indicates that the heat resistance of the copolymer has been improved by decreasing the BMA units. Blends of poly(BMA) and poly(EMA) obtained via the ATRP method have been prepared by casting films from a dichlorormethane solution. The blends have been characterized by differential scanning calorimetry and thermogravimetry. The measurements were comparable with those of copolymers synthesized.
Radical-initiated homo- and copolymerization of acetonyl methacrylate
Journal of Polymer Science Part A: Polymer Chemistry, 1988
As part of a continuing research program on the structure-reactivity relationships exhibited by vinyl monomers, in both their radical-initiated homo-and copolymerizations, the polymerization behavior of methacrylic esters containing heteroatoms at the a-position of alkyl groups has been investigated in our laboratory. In the preceding papers, we reported the results of kinetic studies of the radical polymerizations of chloromethyl methacrylate (ChMA),' cyanomethyl methacrylate (CYMA),~ methoxymethyl methacrylate (Mom): and methylthiomethyl methacrylate (MtMA).4 These investigations have revealed that the introduction of a heteroatoms into the methyl group increases the polar effects in the monomers and thus enhances monomer reactivity in radical polymerization.
Accelerated controlled radical polymerization of methacrylates
Polymer International, 2008
BACKGROUND: Nitroxide adducts 1,1-ditertbutyl-1-(1-methyl-1-cyanoethoxy)-amine (AIBN/DBN), 1,1-ditertbutyl-1-(benzoylperoxy)-amine (BPO/DBN) and 2,2,6,6,-tetramethyl-4-oxo-1-(1-methyl-1-cyanoethoxy)-piperidine (AIBN/4-OXO-TEMPO) were prepared and evaluated as stabilized unimolecular initiators for controlled radical polymerization of methacrylate monomers using sulfuric acid as an accelerating additive. Their effectiveness was evaluated from polymerization rates, molecular weight control and dispersity (D) of the polymers. Thermal stabilities of the polymers were also examined. The monomers used were methyl methacrylate, triethylene glycol dimethacrylate (TEGDMA) and ethoxylated bisphenol A dimethacrylate (EBPADMA). RESULTS: Polymerization was accomplished at 70 and 130 • C in 5 min to 144 h. The value of D of poly(methyl methacrylate) (PMMA) was 1.05-1.22. The glass transition temperature (T g) for PMMA was 122-127 • C. The activity of the chain ends was established by chain extension and controlled polymerization was established by plotting M n versus monomer conversion. First-order kinetics in monomer consumption was established and an electron paramagnetic resonance study was conducted. Decomposition temperature (T d) for PMMA was 360-380 • C, for poly(TEGDMA) was 300-380 • C and for poly(EBPADMA) was 360-440 • C. Photoinitiation without additive yielded no polymer. Thermal initiation by AIBN/4-OXO-TEMPO was the fastest. CONCLUSIONS: The initiators are applicable in low-temperature additive-enhanced controlled polymerization of methacylates and dimethacrylates, producing polymers with excellent attributes and a low value of D.
Atom transfer radical polymerization of cyclohexyl methacrylate at a low temperature
Journal of Polymer Science Part A: Polymer Chemistry, 2005
The atom transfer radical polymerization of cyclohexyl methacrylate (CHMA) is reported. Controlled polymerizations were performed with the CuBr/ N,N,NЈ,NЉ,NЉ-pentamethyldiethylenetriamine catalytic system with ethyl 2-bromoisobutyrate as the initiator in bulk and different solvents (25 vol %) at 40°C. The polymerization of CHMA in bulk resulted in a controlled polymerization, although the concentration of active species was relatively elevated. The addition of a solvent was necessary to reduce the polymerization rate, which was dependent on the dipole moment. Well-controlled polymers were obtained in toluene, diphenyl ether, and benzonitrile solutions. Poly(cyclohexyl methacrylate) as a macroinitiator was used to synthesize the poly(cyclohexyl methacrylate)-b-poly(tert-butyl methacrylate) block copolymer, which allowed a demonstration of its living character. In addition, two difunctional initiators, 1,4-bis(bromoisobutyryloxy) benzene and 1,2-bis(bromoisobutyryloxy) ethane, were used to initiate the atom transfer radical polymerization of CHMA. The experimental molecular weights of the obtained polymers were very close to the theoretical ones. These, along with the relative narrow molecular weight distributions, indicated that the polymerization was living and controlled. For confirmation, two different poly(tert-butyl methacrylate)-b-poly(cyclohexyl methacrylate)-b-poly(tert-butyl methacrylate) triblock copolymers were also synthesized.
The synthesis and polymerization of methacrylate macromonomers
1998
Macromonomers of a range of functional methacrylate monomers are prepared using a catalytic chain transfer agent. The lower molecular weight oligomers, e.g. dimer, trimer, are isolated by reduced pressure distillation and characterised by IR and *H and 13C NMR spectroscopy. It has previously been established in the published literature that methacrylate macromonomers can undergo three different types of reaction when added to radical polymerizations. They can copolymerize or undergo an addition- fragmentation reaction ((5-scission) or they can undergo a depropagation mechanism along the backbone to yield the starting materials. This (5-scission mechanism is utilised to prepare a range of telechelic methacrylate polymers using functional dimers, some of which have been shown to undergo further reactions. The chain transfer constants of MMA dimer, MMA trimer and BMA trimer in bulk polymerizations of MMA and BMA are determined using an integrated form of the Mayo equation. The trends s...