Synthesis of Graft Polymers by Copolymerization of Macromonomers. II. Copolymerization Kinetics of Styrene-and Methacrylate-Terminatedpoly(2-Acetoxyethyl Methacrylate) Macromonomers

Styrene-terminated poly(2-acetoxyethyl methacrylate) macromonomer (EBA), methacrylate-terminated poly(2-acetoxyethyl methacrylate) macromonomer (MPA), and methacrylate-terminated poly(methyl methacrylate) macromonomer (MPM) were synthesized and subjected to polymerization and copolymerization by a free-radical polymerization initiator (AIBN). EBA and MPA were homopolymerized at various concentrations. EBA exhibited higher reactivity than styrene. The reactivity of MPA, however, was almost equal to that of glycidyl methacrylate. Cumulative copolymer compositions were determined by GPC analysis of copolymerization products. The reactivity ratios estimated were r_a = 0.95 and r_b , = 0.90 for EBA macromonomer (a)-methyl methacrylate (b) copolymerization. These values were not consistent with literature values for the styrene-methyl methacrylate and p-methoxy-styrene-methyl methacrylate systems. The reactivity ratios estimated for MPA and 2-bromoethyl methacrylate were r_a - 0.95 and r_b , = 0.98; equal to the glycidyl methacrylate-2-bromoethyl methacrylate system. MPA or MPM was also copolymerized with styrene, and the reactivity ratios were r_a = 0.40, r_a = 0.60 and r_a = 0.39, r_a = 0.58, respectively. These estimates were in good agreement with the reactivity ratios for glycidyl methacrylate and styrene. Thus, no effect of molecular weight was observed for both copolymerization systems.     

Tricarbonylchromium complexes of styrenes in radical copolymerization

The organometallic monomers styrenetricarbonylchromium and p‐methylstyrenetricarbonylchromium were copolymerized in ethyl acetate solutions with methyl methacrylate and butyl acrylate using azobisisobutyronitrile at 50 °C and a binary system including di‐tert‐butylperoxytriphenylantimony at 30 °C as the free‐radical initiators. Comonomers are proposed to form a molecular complex based on the results of ultraviolet and electron spin resonance spectroscopy. A kinetic study shows that chromium‐containing monomers at high concentrations in the mixture reduce the rate of copolymerization. The addition of styrenetricarbonylchromium to butyl acrylate significantly slows down the autoacceleration. The reactivity ratios of the comonomer pairs, namely, styrenetricarbonylchromium–methyl methacrylate, styrenetricarbonylchromium–butyl acrylate and p‐methylstyrenetricarbonylchromium–methyl methacrylate, were determined using the method of Kelen–Tudos for low conversion polymerizations.Copyright © 2001 John Wiley & Sons, Ltd.     

Dielectric properties of some photo crosslinking acrylate ester copolymers

Photo crosslinking due to the photo polymerization of unsaturated acrylic side-groups attached to copolymers of glycidyl methacrylate and methyl methacrylate (GMA-MMA) by reaction with acrylic acid in the presence of benzoin methyl ether as photolabile initiator has been investigated. The composition of these copolymers based on (GMA-MMA, 30:70) were determined by [¹H] NMR spectroscopy. The reactivity ratios for the GMA-MMA system were determined using the Kelen-Tüdös method.

The dielectric properties of copolymers based on GMA-MMA acrylate ester (30:70) and homopolymers of MMA in combination with different polyfunctional acrylate ester monomers before and after exposure to UV irradiation have been studied in a solid state matrix, over a frequency range of 100 Hz to 50 kHz and at temperatures in the range 20–70°C.     

Functional polymers. VI. Preparation and polymerization of methyl 3-vinylsalicylate,methyl 3-vinylacetylsalicylate, 3-vinylsalicylic acid,and 3-vinylacetylsalicylic acid

The title compounds were synthesized and their homopolymerizations and copolymerizations with styrene and a number of acrylic monomers were investigated. Methyl 3-vinylacetylsalicylate was prepared in a five-step synthesis from 2-ethylphenol in an overall yield of 40%. Methanolysis of this compound gave methyl 5-vinylsalicylate in 63% yield. Hydrolysis of methyl 3-vinylsalicylate gave a nearly quantitative yield of 3-vinylsalicylic acid which could be acetylated to 3-vinylacetylsalicyclic acid (3-vinyl aspirin). 3-Vinylsalicylic acid derivatives were readily homopolymerized and copolymerized with styrene, methyl methacrylate, and methacrylic acid, and 3-vinylsalicyclic acid was copolymerized with a number of vinyl and acrylic monomers. Copolymer compositions were determined by examination of ¹H-NMR spectra.     

Boron subphthalocyanine polymers: Avoiding the small molecule side product and exploring their use in organic light‐emitting diodes

In this study, we set out the steps to efficiently synthesize boron subphthalocyanine (BsubPc)‐containing polymers while circumventing the formation of a known side product. The synthesis was achieved using the post‐polymerization coupling reaction of a carboxylic acid functional prepolymer with bromo‐BsubPc. We have earlier shown that when copolymerizing styrene and acrylic acid (AA) a significant amount of an undesired side product is formed. In this study, we have determined that this side product persisted when styrene was copolymerized with AA or n‐butyl acrylate but could be avoided when styrene was copolymerized with methacrylic acid (MAA), methyl methacrylate, or acrylonitrile. Therefore, MAA/styrene copolymer, synthesized by nitroxide‐mediated polymerization was chosen to be coupled to BsubPc. The resulting BsubPc polymer was found to have similar electrochemical properties, solution state absorption and photoluminescence characteristics when compared against a small molecule model compound although the solid‐state PL emission of the polymer was found to be excitation wavelength dependent. Finally, preliminary organic light‐emitting diodes (OLEDs) were fabricated to assess the potential role(s) of the BsubPc polymer in organic electronic devices. These OLEDs represent the first‐solution processed organic electronic devices containing BsubPc polymers as a functional material. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1996–2006     

Aminimides. IV. Homo- and copolymerization studies on trimethylamine methacrylimide

Trimethylamine methacrylimide (TAMI) has been homo- and copolymerized with methyl methacrylate, vinyl acetate, vinyl chloride, hydroxypropyl methacrylate, and acrylonitrile by free-radical initiators to soluble, low molecular weight polymers containing pendant aminimide groups along the backbone of the polymer chains. The reactivity ratios in the copolymerization of TAMI (M₁) with acrylonitrile (M₂) were determined: r₁ = 0.10 ± 0.01, r₂ = 0.37 ± 0.04. The Alfrey-Price Q and e values for TAMI were also calculated: Q = 0.18, e = ?0.60. This preliminary work indicates that TAMI has potential for the preparation of reactive polymers.     

Polyolefin graft copolymers via living polymerization techniques: Preparation of poly(n‐butyl acrylate)‐graft‐polyethylene through the combination of Pd‐mediated living olefin polymerization and atom transfer radical polymerization

Poly(n‐butyl acrylate)‐graft‐branched polyethylene was successfully prepared by the combination of two living polymerization techniques. First, a branched polyethylene macromonomer with a methacrylate‐functionalized end group was prepared by Pd‐mediated living olefin polymerization. The macromonomer was then copolymerized with n‐butyl acrylate by atom transfer radical polymerization. Gel permeation chromatography traces of the graft copolymers showed narrow molecular weight distributions indicative of a controlled reaction. At low macromonomer concentrations corresponding to low viscosities, the reactivity ratios of the macromonomer to n‐butyl acrylate were similar to those for methyl methacrylate to n‐butyl acrylate. However, the increased viscosity of the reaction solution resulting from increased macromonomer concentrations caused a lowering of the apparent reactivity ratio of the macromonomer to n‐butyl acrylate, indicating an incompatibility between nonpolar polyethylene segments and a polar poly(n‐butyl acrylate) backbone. The incompatibility was more pronounced in the solid state, exhibiting cylindrical nanoscale morphology as a result of microphase separation, as observed by atomic force microscopy. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2736–2749, 2002     

Homogeneous and multiphase poly(methyl methacrylate) graft polymers via the macromonomer method

Anionic and group transfer polymerization processes were used to synthesize controlled molecular weight methacryloyloxy functionalized poly(dimethylsiloxane) and poly(methyl methacrylate) macromonomers having a narrow molecular weight distribution and high percent functionality. These macromonomers were anionically copolymerized with methyl methacrylate (MMA) to afford poly(methyl methacrylate)-graft-poly(methyl methacrylate) (PMMA-g-PMMA) and poly(methyl methacrylate)-graft-poly(dimethylsiloxane) (PMMA-g-PDMS) polymers having not only narrow molecular weight distribution graft parts but also backbone parts. The PMMA-g-PDMS system was fractionated using supercritical chlorodifluoromethane to determine its chemical composition distribution (CCD). The CCD for the PMMA-g-PDMS copolymerized in a living manner was substantially more narrow than the free radically copolymerized material. The PMMA-g-PMMA system was used to study the dilute solution properties of branched homopolymers. The appropriateness of the universal calibration gel permeation chromatography (GPC) method for branched systems exhibiting long chain branching was reaffirmed.     

A novel synthetic procedure of vinylacetamide and its free radical polymerization

The pyrolysis of N-(α-methoxyethyl) acetamide, which was obtained by one-step reaction of acetamide, acetaldehyde, and methanol, gave N-vinylacetamide (NVA) in a good yield. The polymerizability and copolymerizability of NVA were studied. Free radical polymerization was carried out in the presence of radical initiator or by γ-ray irradiation. The monomer reactivity ratios of NVA were estimated in the copolymerization with acrylamide, vinyl acetate, and methyl methacrylate. The solvents were found to influence the monomer reactivity ratio. NVA showed a typical copolymerizability as nonconjugated vinyl monomer, and Q and e values were obtained in DMF as 0.16 and ?1.57, respectively.     

Polymerization and copolymerization in associated monomer aggregates

The polymerization of acrylic acid in bulk is controlled by linear plurimolecular H-bonded aggregates of the monomer which lead to the formation of a syndiotactic polymer. Polar solvents do not dissociate these aggregates unless high dilutions are reached. In contrast, “normal” kinetics are observed in the presence of 10–20 per cent toluene, n-hexane or chloroform. The polymerization of methacrylic acid is not affected to the same extent by molecular aggregates. In the copolymerization of acrylic acid with methyl acrylate or acrylonitrile, the reactivity ratios are altered by solvents. The acrylic acid content is higher in copolymers formed in bulk than in toluene solution. But similar effects are observed in the presence of DMF which does not dissociate the aggregates of acrylic acid; moreover, copolymerization data obtained with methacrylic acid indicate that other factors may be involved in determining reactivity ratios.Acrylamide also forms H-bonded aggregates and its copolymerization behaviour is strongly affected by solvents. No simple correlation holds, however, between reactivity ratios and extent of association.A very strict control of chain propagation occurs when 4-vinylpyridine is polymerized in the presence of polycarboxylic acids. A considerable rate increase was observed when vinylpyridine was grafted into polytetrafluoroethylene films which contained poly(acrylic acid) branches. This effect is explained by assuming that the pyridine groups form strong associations with the carboxylic sites, thereby providing a very favourable orientation of the vinyl groups for chain propagation.     

Grafting onto Wool. IX. Graft Copolymerization of Vinyl Monomers by Use of Vanadium Oxyacetylacetonate as Initiator

Methyl methacrylate (MMA), acrylic acid (AAc), and vinyl acetate (VAc) were graft copolymerized onto Himachali wool in an aqueous medium by using vanadium oxyacetyl acetonate as initiator. Graft copolymerization was studied at 45, 55, 65, and 75°C for various reaction periods. The percentage of grafting was determined as functions of concentration of monomers, concentration of initiator, time, and temperature. The maximum percentage of grafting with each monomer occurred at 55°. Several grafting experiments were carried out in the presence of various additives which include HNO3, DMSO, and pyridine. Nitric acid was found to promote grafting of MMA. All these additives had adverse effects on grafting of VAc and AAc. MMA, VAc, and AAc were found to differ in reactivity toward grafting and followed the order MMA > AAc > VAc.     

Oligomerization and Copolymerization of Endo-N-Benzylbicyclo[2,2,1]Hept-2-Ene-5,6-Dicarboximide

ABSTRACT

endo-N-Benzylbicyclo[2,2,1]hept-2-ene-5,6-dicarboximide (BZN or endo-BZN), one of the norbornene derivatives, was prepared from N-benzylmaleimide (BZMI) and cyclopentadiene (CPD) according to the Diels-Alder reaction. Yields of homopolymers, insoluble in methanol, were about 20 wt%. No BZN could be polymerized in bulk without radical catalysts under 220°C. At 220°C for 1 h, endo-BZN was converted to exo-BZN in a 50-mol% yield. the polymerization of BZN over 300°C for 1 h gave the polymer in about 100% yield. It was found that the polymer consisted of a mixture of BZN, BZMI, and an adduct obtained from BZN and CPD. BZN was copolymerized with styrene, methyl methacrylate, and vinyl acetate with radical initiators. the copolymerizabilities of BZN with VAc were better than those for other systems. the monomer reactivity ratios and Alfrey-Price Q-e values were determined.     

Synthesis and properties of graft copolymers based on poly(3-hydroxybutyrate) macromonomers

Graft copolymers of poly(methyl methacrylate) with poly(3-hydroxybutyrate), PHB, segments as long side chains were prepared by the macromonomer method. PHB macromonomers were prepared from the esterification of oligomers with 2-hydroxyethyl methacrylate at their carboxylic acid end. Esterification products displayed low polydispersity indices (ca. 1.2) and a functionality of over 83%, with a Mn of 2,020. Using free radical polymerization methods, the macromonomers were copolymerized with methyl methacrylate to yield graft (comb type) copolymers at different comonomer feed ratios. The graft copolymers contained from 0.5 to 14 mol-% of PHB blocks, with a glass transition temperature decreasing from 100 to 3 degrees C.     

Copolymerization of acrylonitrile with 3-chloro, 2-hydroxy-propyl acrylate and methacrylate

Acrylonitrile (AN) was copolymerized with 3-chloro, 2-hydroxy propyl acrylate (CHPA) and 3-chloro, 2-hydroxy-propyl methacrylate (CHPMA) in water and water-acetone medium at 40°C with potassium persulfate and sodium metabisulfite as redox initiators. Copolymer composition was determined from the nitrogen content. The reactivity ratios for the AN-CHPMA system were also calculated by the Kelen–Tudos method. The reactivity ratio r₂ (CHPMA) was higher for the AN-CHPMA system in both media, which indicated higher reactivity of CHPMA toward the propagation species. Addition of acetone decreases r₂ and increases r₁. It was found that the copolymers prepared in water medium were not completely soluble in dimethylformamide (DMF); the insoluble fraction was rich in CHPA/CHPMA and increased with increasing comonomer composition. The influence of the acrylate comonomer on properties such as solubility and intrinsic viscosity was also studied.     

Mechanical Activation of Inorganic Powders by vibromilling

Mechanochemical polymerization of vinyl monomers on vibromilled aluminum, iron and silica powders were examined at 293 K. It was found that aluminum and silica powders were effective as an initiator for the polymerization even after milling. The order of the monomer reactivity on the vibromilled silica powder was vinyl acetate < styrene < methyl methacrylate < acrylonitrile and it was in agreement with the order of monomer reactivity in anionic polymerization. The activity of examined powders as the initiator for the polymerization of methyl methacrylate was iron < aluminum ? silica and it was explained by the emission intensities and the kinetic energies of exoelectron emitted from powders.     

Synthesis and copolymerization of new phosphorus‐containing acrylates

Two phosphorus‐containing acrylate monomers were synthesized from the reaction of ethyl α‐chloromethyl acrylate and t‐butyl α‐bromomethyl acrylate with triethyl phosphite. The selective hydrolysis of the ethyl ester monomer with trimethylsilyl bromide (TMSBr) gave a phosphonic acid monomer. The attempted bulk polymerizations of the monomers at 57–60 °C with 2,2′‐azobisisobutyronitrile (AIBN) were unsuccessful; however, the monomers were copolymerized with methyl methacrylate (MMA) in bulk at 60 °C with AIBN. The resulting copolymers produced chars on burning, showing potential as flame‐retardant materials. Additionally, α‐(chloromethyl)acryloyl chloride (CMAC) was reacted with diethyl (hydroxymethyl)phosphonate to obtain a new monomer with identical ester and ether moieties. This monomer was hydrolyzed with TMSBr, homopolymerized, and copolymerized with MMA. The thermal stabilities of the copolymers increased with increasing amounts of the phosphonate monomer in the copolymers. A new route to highly reactive phosphorus‐containing acrylate monomers was developed. A new derivative of CMAC with mixed ester and ether groups was synthesized by substitution, first with diethyl (hydroxymethyl)phosphonate and then with sodium acetate. This monomer showed the highest reactivity and gave a crosslinked polymer. The incorporation of an ester group increased the rate of polymerization. The relative reactivities of the synthesized monomers in photopolymerizations were determined and compared with those of the other phosphorous‐containing acrylate monomers. Changing the monomer structure allowed control of the polymerization reactivity so that new phosphorus‐containing polymers with desirable properties could be obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2207–2217, 2003     

Statistical radical copolymerization of styrene and methyl methacrylate in a room temperature ionic liquid

Use of a room temperature ionic liquid as the medium for conventional free radical copolymerization of styrene and methyl methacrylate resulted in reactivity ratios that were significantly different from those obtained in conventional organic solvents or in bulk, demonstrating that polymerization in this alternative medium offers potential to create copolymers having new monomer sequences.     

Effect of Glycerol in the Polymerization of Methyl Methacrylate by Mn(III) Acetate

The kinetics of the mechanism of the polymerization of methyl methacrylate initiated by the glycerol/Mn(III) acetate redox system has been investigated in aqueous sulfuric acid medium in the temperature range of 40 to 50 °C. The effects of glycerol, methyl methacrylate, metal ion, acetic acid, and sulfuric acid on the rates of polymerization have been studied. One striking observation is that the increase in monomer concentration steadily decreases the rate of polymerization, contrary to what was observed in the case of acrylonitrile. On the basis of these observations, an appropriate kinetic scheme and rate expression have been developed.     

Tacticity control in the radical polymerization of 2,2,2-trifluoroethyl methacrylate with fluoroalcohol

The free-radical polymerization of 2,2,2-trifluoroethyl methacrylate (TEMA) was carried out in fluoroalcohols to achieve stereoregulation. The polymerization reactivity at low temperature and syndiotactic specificity were enhanced by the use of fluoroalcohol as a solvent. The polymer having triad syndiotacticity (rr) of 70% was obtained in perfluoro-t-butyl alcohol. It was noted that the stereochemistry was nearly independent of reaction temperature. The stereoeffect of fluoroalcohols seemed to be due to the hydrogen-bonding interaction between the alcohol and the monomer or growing species. The hydrogen-bonding formation was determined by FTIR. The copolymerization of TEMA with methyl methacrylate (MMA) in hexafluoroisopropanol afforded a copolymer with syndiotactic specificity. By this method, a cladding material for an optical fiber based on poly(methyl methacrylate) (PMMA) with high mechanical strength and low refractive index could be obtained.     

Chain transfer constants for vinyl monomers polymerized in methyl oleate and methyl stearate

Chain transfer constants were obtained for styrene, methyl methacrylate, methyl acrylate and vinyl acetate, polymerized in methyl oleate and methyl stearate at 60°C. Transfer constants increased in the order: methyl methacrylate < styrene < methyl acrylate ? vinyl acetate in both solvents. Average values of the transfer parameters were: for methyl oleate, Q_tr = 2.04 × 10^?4, e_tr = 1.08; for methyl stearate, Q_tr = 0.373 × 10^?4, e_tr = 1.01. Indication that polar species predominate in the transition state is supported by the observed order of reactivity. The usual rate dependence appeared to be followed by all of the monomers except vinyl acetate, which was retarded, severely in methyl oleate. Transfer in methyl oleate was about 5.8 times greater than that found in methyl stearate for these four monomers. The internal allylic double bond of methyl oleate had about the same reactivity in transfer as had the terminal unsaturation in N-allylstearamide at 90°C. Rough estimates were obtained of the monomer transfer constants for the long side-chain homologs of these four monomers from the respective monomer transfer constants and the experimental transfer constants, corrected for transfer to the labile groups of the solvent. It was concluded that the rate of polymerization would determine in large measure the degree of polymerization for the reactive 18-carbon homologs but that the molecular weight of poly(vinyl stearate) and (oleate) will be regulated primarily by transfer to monomer.