Cationic polymerization of 4-methyl-1,3-dioxene-4 and copolymerization with tetrahydrofuran

A new monomer, 4-methyl-1,3-dioxene-4 was synthesized from allyl chloride and paraformaldehyde. The monomer was polymerized at room temperature or ?78°C. by boron trifluoride etherate catalyst, and the structure of the obtained polymer was determined by infrared, nuclear magnetic resonance spectra, and chemical analysis. It was ascertained that the polymerization process proceeded through a ring-opening mechanism at the dioxane ring. In the presence of tetrahydrofuran, the polymerization of 4-methyl-1–1,3-dioxene-4 led to copolymer. The mechanism of the copolymerization is described in detail.     

Characterization of chloroprene and maleic anhydride copolymer by 13C-NMR spectroscopy and pyrolysis GC/MS

The radical copolymerizations of chloroprene (CP) and maleic anhydride (MAH) were carried out with AIBN in 1,4-dioxane at 60°C. The monomer reactivity ratios were estimated as r₁ (CP) = 0.38 and r₂ (MAH) = 0.07. Microstructures in the copolymer of chloroprene (CP) and maleic anhydride (MAH) were investigated by 75.4 MHz ¹³C-and 300 MHz ¹H-NMR spectroscopies. Resonances were assigned to the monomer sequence dyads CC, CM, and MC (C = chloroprene, M = maleic anhydride). Well resolved fine structure in the ¹³C-NMR spectra showed that 1,2- and 3,4-structural chloroprene units were negligible in the copolymer. The pyrolysis characterization of the copolymer was also investigated by the pyrolysis gas chromatography mass spectrometry (GC/MS). The fragments of CP and MAH monomers and CP-MAH hybrid dimer, CO, and CO₂ were identified after pyrolysis of the copolymer. © 1994 John Wiley & Sons, Inc.     

Alternating copolymerization of ethylene with maleic anhydride

The copolymerization of ethylene with maleic anhydride was carried out with γ-radiation and a radical initiator, i.e., 2,2′-azobisisobutyronitrile and diisopropyl peroxydicarbonate under pressure at various reaction conditions. The homopolymerization of neither monomer was observed in this system. In the γ-ray-initiated copolymerization the G value (polymerized monomer molecules per 100 e.v.) was shown to be between 10³ and 10⁴. It was found that the dose rate exponent of the rate is approximately unity, and the rate is proportional to the amount of ethylene monomer. Apparent activation energies of 1.8 and 27.5 kcal./mole were obtained for γ-ray-initiated and AIBN-initiated copolymerization, respectively. Since the composition of copolymer is independent of monomer molar ratio and the molar ratio of ethylene to maleic anhydride in the polymer is approximately unity, the monomer reactivity ratios were obtained as r_E ? 0 and r_M ? 0 for γ-ray-initiated polymerization at 40°C. Alternating copolymerization was, therefore, concluded to occur. Infrared analysis of the copolymer is almost consistent with this. The copolymer in the solid state is amorphous. It is soluble in water, cyclohexane, and dimethylformamide and insoluble in lower alcohols, ether, and aromatic hydrocarbons. The aqueous solution of polymer gave a strong acid.     

Diels-Alder-Reaktionen mit aktivierten 4-Methyl-1,3-pentadienen

Diels-Alder Reactions with Activated 4-Methyl-1,3-pentadienes Ethyl 4-methyl-1,3-pentadienyl ether, trimethyl[(4-methyl-1,3-pentadienyl)oxy]silane, and 1-(4-methyl-1,3-pentadienyl)pyrrolidine and the corresponding piperidine analogue have been used in Diels-Alder reactions with acrylonitrile, ethyl acetylenedicarboxylate, maleic anhydride, and 2,6-dimethyl-p-benzoquinone.     

Vinylhydroquinone. IV. Preparation and polymerization behavior of 2-methyl-5-vinylhydroquinone derivatives

As in the case of vinylhydroquinone (I), its alkyl-substituted derivative, 2-methyl-5-vinylhydroquinone (II) was found to copolymerize with methyl methacrylate by tri-n-butylborane in cyclohexanone at 30°C. II was prepared from the O,O′-bisether compound, 2-methyl-5-vinyl-O,O′-bis(1′-ethoxyethyl)hydroquinone (III). The monomer reactivity ratios (M₂ = II) were determined to be r₁ = 0.37 and r₂ = 0. No homopolymerization proceeded under the same conditions. Ordinary free-radical initiators, such as azobisisobutyronitrile and benzoyl peroxide, were not effective in the homopolymerization of II. 1:1 Copolymers were obtained from II and maleic anhydride by using tri-n-butylborane as an initiator. The copolymers exhibited no definite melting range and decomposed at 370–375°C endothermally (DSC). The polymerization behavior of III was also investigated. Although tri-n-butylborane did not initiate the homopolymerization of the monomer, azobisisobutyronitrile was capable of initiating the homopolymerization and copolymerization of III. The monomer reactivity ratios (M₁ = styrene) were determined to be r₁ = 0.83 and r₂ = 0.18. The ratios gave the following Q and e values; Q = 0.15 and e = ?2.2.     

Monomer-isomerization polymerization. XVIII. Monomer-isomerization copolymerizations of 4-phenyl-2-butene with 4-methyl-2-pentene and 3-heptene with Ziegler-Natta catalyst

4-Phenyl-2-butene (4Ph2B) undergoes monomer-isomerization copolymerization with 4-methyl-2-pentene (4M2P) and 2-and 3-heptene (2H and 3H) with TiCl₃–(C₂H₅)₃Al catalyst at 80°C to produce copolymer consisting exclusively of 1-olefin units. For comparison the copolymerization of 4-phenyl-1-butene (4Ph1B) with 4-methyl-1-pentene (4M1P) and 1-heptene (1H) was carried out under similar conditions. The composition of the copolymers obtained from these copolymerizations was determined from the ratios of optical densities D₁₃₈₀ and D₁₆₀₀ of infrared (IR) spectra of their thin films. The apparent monomer reactivity ratios for the monomer-isomerization copolymerization of 4Ph2B with 4M2P, 2H, and 3H in which the concentration of olefin monomer in the feed was used as internal olefin and those for the copolymerization of 4Ph1B with 4M1P and 1H were determined as follows: 4Ph2B(M₁)-4M2P(M₂); r₁ = 0.90, r₂ = 0.20, 4Ph1B(M₁)-4M1P (M₂); r₁ = 0.40, r₂ = 0.70, 4Ph2B(M₁)-2H(M₂); r₁, = 0.45, r₂ = 1.85, 4Ph2B(M₁)-3H(M₂); r₁ = 0.50, r₂ = 1.20, 4Ph1B(M₁)-1H(M₂); r₁ = 0.55, r₂ = 0.75. The difference in monomer reactivity ratios seemed to originate from the rate of isomerization from 2- or 3-olefins to 1-oletins in these monomer-isomerization copolymerizations.     

Synthesis and polymerization of N-[4-N′- (α-methylbenzyl)aminocarbonylphenyl]maleimide

A novel type of optically active N-[4-N′-(α-methylbenzyl)aminocarbonylphenyl]maleimide [(R)-MBCP] was synthesized from maleic anhydride, p-aminobenzoic acid, and (R)-methylbenzylamine. Radical homopolymerization of (R)-MBCP was performed in tetrahydrofuran (THF) at 50 and 70°C for 24 h to give optically active polymers having [α]²⁵_D = -141° and -129°, respectively. Anionic polymerization of (R)-MBCP with n-butyllithium in THF and N,N-dimethylformamide gave an optically active polymer having ?78 to ?81° of [α]²⁵_D. Radical copolymerizations of (R)-MBCP (M₁) were performed with styrene (ST, M₂) and methyl methacrylate (MMA, M₂) in THF at 50°C. The monomer reactivity ratios (r₁, r₂) and the Alfrey-Price Q-e values were determined as follows: r₁ = 0.009, r₂ = 0.091, Q₁ = 1.30, e₁ = 1.87 in the (R)-MBCP-ST; r₁ = 0.27, r₂ = 1.21, Q₁ = 0.93, e₁ = 1.46 in the (R)-MBCP-MMA system. Chiroptical properties of the polymers were also investigated. © 1992 John Wiley & Sons, Inc.     

Esterolytic activity of imidazole-containing polymers. Synthesis and characterization of copoly[1-alkyl-4- or 5-vinylimidazole/4(5)-vinylimidazole] and its catalytic activity in the hydrolysis of p-nitrophenyl acetate

The water-soluble monomers, 1-methyl-4-vinylimidazole, 1-methyl-5-vinylimidazole, 1-ethyl-5-vinylimidazole, and 1-propyl-5-vinylimidazole have been synthesized, polymerized, and copolymerized with 4(5)-vinylimidazole. The copolymers were characterized by ¹⁴C-labeling, NMR, pK_a determination and viscosity measurements. The monomer reactivity ratios determined by ¹⁴C counting are r₁ = 1.04; r₂ = 0.94 [M₁ = 4(5)-vinylimidazole, M₂ = 1-methyl-4-vinylimidazole] and r₁ = 1.01; r₂ = 0.86 [M₁ = 4(5)-vinylimidazole, M₂ = 1-methyl-5-vinylimidazole]. The esterolytic activity of the copolymers for the hydrolysis of p-nitrophenyl acetate (PNPA) at pH 7–8 in 28.5% ethanol–water was higher than that of the mixtures of homopolymers. At pH 5–6 the esterolytic activities of the copolymers and the mixtures were similar. The most efficient esterolytic activity for PNPA hydrolysis at pH 7.11 in 28.5% ethanol–water occurred for copolymers containing 75 mole % 4(5)-vinylimidazole and for copolymers containing 1-methyl-4-vinylimidazole rather than 1-methyl-5-vinylimidazole.     

Spontaneous copolymerization of 4-methylene-1,3-dioxolanes with maleic anhydride

The copolymerization of methylenedioxolanes, such as 4-methylene-1,3-dioxolane (I) and 2,2-dimethyl-4-methylene-1,3-dioxolane (II), with maleic anhydride (Manh) gives rise spontaneously to the alternating copolymers by the participation of charge-transfer (CT) complexes. The formation of CT complexes I-Manh and II-Manh was ascertained by UV and NMR spectroscopies. The equilibrium constants (K) could not be determined but were assumed to be small (K ? 1). For comparison with these systems an investigation of I-dimethyl maleate (DMM) and II-DMM systems was carried out to estimate K values 0.115 and 0.157 L/mol, respectively. To clarify the copolymerization mechanism I-Manh-acryronitrile was terpolymerized. Consequently it was concluded that the spontaneous copolymerization of I-Manh and II-Manh systems is effected by the CT complex monomer mechanism.     

Monomer-isomerization polymerization. XVII. Monomer-isomerizations copolymerizations of 2-butene with 3-heptenes and 4-methyl-2-pentenes with Ziegler-Natta catalyst

2-Butene(2B) copolymerizes with 3-heptene(3H) and 4-methyl-2-pentene(4M2P) by a monomer-isomerization copolymerization mechanism in the presence of TiCl₃–(C₂H₅)₃Al catalyst at 80°C to yield the copolymers of 1-olefin units. By comparison, the copolymerization of 1-butene(1B) with 4-methyl-1-pentene(4M1P) was also carried out under similar conditions. The composition of the copolymers obtained from these copolymerizations was determined from the ratios of optical densities D₇₂₃/D₁₃₈₀ and D₁₁₇₀/D₁₃₈₀ in their infrared (IR) spectra. The apparent monomer reactivity ratios for the monomer-isomerization copolymerization of 2B with 3H and 4M2P, in which the concentration of olefin monomer in the feed was used as 2-olefin, were determined as follows: cis-2B(M₁)/3H(M₂); r₁ = 4.00, r₂ = 0.20: trans-2B(M₁)/3H; r₁ = 3.50, r₂ = 0.20; 4M2P(M₁)-trans-2B(M₂): r₁ = 0.05, r₂ = 9.0. These results indicate that the isomerization of 2-olefins to 1-olefins was important to monomer-isomerization copolymerization.     

Cationic copolymerization of cyclic ketene acetals: The effect of substituents on reactivity

Cationic copolymerizations of 4-methyl-2-methylene-1,3-dioxane, 2 (M₁), with 2-methylene-1,3-dioxane, 1 (M₂); of 4,4,6-trimethyl-2-methylene-1,3-dioxane, 3 (M₁), with 2-methylene-1,3-dioxane, 1 (M₂); of 4-methyl-2-methylene-1,3-dioxolane, 5 (M₁), with 2-methylene-1,3-dioxolane, 4 (M₂); and of 4,5-dimethyl-2-methylene-1,3-dioxolane, 6 (M₁), with 2-methylene-1,3-dioxolane, 4 (M₂) were conducted. The reactivity ratios for these four types of copolymerizations were r₁ = 1.73 and r₂ = 0.846; r₁ = 2.26 and r₂ = 0.310; r₁ = 1.28 and r₂ = 0.825; r₁ = 2.23 and r₂ = 0.515, respectively. The relative reactivities of these monomers towards cationic polymerization are: 3 > 2 > 1; and 6 > 5 > 4. With both five- and six-membered ring cyclic ketene acetals, the reactivity increased with increasing methyl substitution on the ring. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 861–871, 1998     

Synthesis and Polymerization of N-(L-Menthylcarboxylatomethyl)maleimide

A new type of optically active N-(L-menthylcarboxylatomethyl)maleimide (MGMI) was synthesized from maleic anhydride, glycine, and L-menthol. Radical homopolymerization of MGMI was performed at 50°C for 24 h to give optically active polymer having [α]_D = -57°. Radical copolymerizations of MGMI (M ₁) were performed with styrene (ST, M ₂), methyl methacrylate (MMA, M ₂) in benzene at 50°C. From the results, the monomer reactivity ratios (r ₁, r ₂) and the Alfrey-Price Q, e values were determined as follows: r ₁ = 0.16, r ₂ = 0.006 for the MGMI-ST system; r ₁ = 0.15, r ₂ = 1.65 for the MGMI-MMA system, and Q ₁ = 0.72, e ₁ = 1.59 calculated from the MGMI-MMA system. Anionic homopolymerizations of MGMI were also carried out. Chiroptical properties of the polymers were investigated.     

Copolymerization of isopropenyl and isopropylidene oxazolones with styrene

2-Isopropenyl-4-isopropyl-2-oxazolin-5-one (M₂), was copolymerized with styrene (M₁), and the monomer reactivity ratios were determined to be r₁ = 0.31 ± 0.03, r₂ = 1.12 ± 0.10. New isomerized oxazolones (M₂), 2-isopropylidene-4-methyl-3-oxazolin-5-one, 2-isopropylidene-4-isopropyl-3-oxazolin-5-one, and 2-isopropylidene-4-isobutyl-3-oxazolin-5-one were prepared and copolymerized with styrene. The monomer reactivity ratios were: r₁ = 0.36 = 0.07, r₂ = 0.0; r₁ = 0.39 ± 0.06, r₂ = 0.00 ± 0.10; r₁ = 0.39 ± 0.10, r₂ = 0.0, respectively. The isomerized oxazolones showed no tendency towards homopolymerization by radical initiator. From the results of infrared and NMR spectra and hydrolysis of the copolymer, it was indicated that the isomerized oxazolones participated in copolymerization in the form of 1–4 polymerization of the conjugated dienes (exo double bond at C₂ and the C?N in the ring). Copolymers reacted with nucleophilic reagents such as amines and alcohols.     

Terpolymerization of maleic anhydride with vinyl monomers

The relative reactivity of vinyl monomers characterized by electron donor and electron acceptor properties in free radical terpolymerization with maleic anhydride has been compared on the basis of product composition analysis. Terpolymers containing ca. 50 mol % of maleic anhydride were obtained in systems containing two electron donor monomers and the relative reactivity of them increases in the following order: 1-hexene < propylene ≈ isobutylene < styrene < isoprene < 1,3-butadiene. In systems consisting of an electron donor monomer and two electron acceptor monomers (i.e., maleic anhydride and an acrylic monomer), the composition of the terpolymers formed depends essentially on the resonance stabilization of the electron donor monomer. With a rise of their resonance stabilization, the content of acrylic monomeric units decreases and the share of alternating sequences of the electron donor and maleic anhydride monomeric units increases. It was found that the relative reactivity of maleic anhydride in all such systems is much greater than that predicted on the basis of reactivity ratios determined in binary systems. The relative reactivity of the studied acrylic monomers decreases in the order: methyl methacrylate > methyl acrylate > acrylonitrile. In the presence of catalytic amounts of ZnCl₂ the content of acrylic monomeric units clearly increases in the products obtained, mainly as a result of homopropagation. The results obtained are discussed in terms of the classical mechanism of propagation and the complex participation model.     

SYNTHESIS AND THERMAL PROPERTIES OF A NEW CHOLIC ACIDCONTAINING COPOLYMER

A new copolymer was synthesized by free radical polymerization in solution from methyl 3α-methylacryloyl-7α, 12α-dihydroxy-5β-cholan-24-oate (MACAME) and maleic anhydride (MAN). The copolymer was characterized by FT-IR and functional group analysis. The reactivity ratios of the two monomers were estimated [r_1 = 11.6 (MACAME), r_2 = 0.01(MAN)] by conducting a series of copolymerizations with a variety of monomer feed compositions and analyzing thecopolymer composition. Thermogravimetric and differential scanning calorimetric analyses of the samples indicate that thecopolymer possesses good thermal stability. The temperature at which the copolymer samples experienced a 10% weight loss(T_(WL)) is over 287℃, and the T_g ranged from 174 to 185℃ for the copolymers.     

Copolymerization of 2-phenylvinyl alkyl ethers and maleic anhydride

A series of 2-phenylvinyl alkyl ethers (I) having as alkyl group methyl, ethyl, n-propyl, n-butyl, 2-methylbutyl, 3-methylpentyl, and optically active 1-methylpropyl of (S) absolute configuration, were copolymerized with maleic anhydride to alternating copolymers. The copolymerizations were carried out in bulk at 70°C in the presence of AIBN as initiator. Monomer I (R = Et) was also polymerized with lauroyl and benzoyl peroxide as initiator. The yield and molecular weight were highest when equimolar amounts of both monomers were used. The equilibrium constant of charge-transfer complex of monomer I (R = Et) and maleic anhydride was determined by the transformed Benessi-Hildebrand NMR method and has a value of 0.28 mole/1.     

Synthesis of poly(4-vinylbenzocyclobutene) and its reaction with dienophiles

4-Vinylbenzocyclobutene ( 1 ) was prepared by the nickel-catalyzed coupling reaction of 4-bromobenzocyclobutene with vinylbromide in 70% yield. Radical homopolymerization of 1 at 60°C for 24 h afforded poly(4 vinylbenzocyclobutene) [poly( 1 )] in 89% yield and radical copolymerizations of 1 with styrene (St) or methyl methacrylate (MMA) were carried out to obtain the corresponding copolymers. The Q = 1.07, e = 0.046. As a model reaction of the polymer reaction of the polymer reaction of poly( 1 ) and poly(4-vinylbenzocyclobutene-co-styrene) [copoly( 1 -St)] with dienophiles, the Diels-Alder reaction of benzocyclobutene with N-phenylmaleimide (MI) or maleic anhydride (MANH) was carried out to determine the optimum reaction conditions. Under the optimum condition, the Diels-Alder reaction of poly( 1 ) and copoly( 1 -St) with MI and MANH in the presence of 4-tert-butyl-catechol as an inhibitor were carried out to yield the corresponding polymers in good yields. The properties (solubilities, T_g, and temperature of 10% weight loss) of the products obtained from the polymer reaction were different from these of poly( 1 ). © 1995 John Wiley & Sons, Inc.     

A study of the relative reactivity of maleic anhydride and some maleimides in free radical copolymerization and terpolymerization

Composition data for the free radical copolymerization of maleic anhydride with N-phenylmaleimide in toluene at 60°C have been obtained. Relative reactivity ratios in terminal and penultimate models using nonlinear least-squares optimization routine have been determined. The standard error was found to be somewhat smaller in the penultimate model, but is still larger than the uncertainty estimated for the copolymer composition. Terpolymers of maleic anhydride and styrene with maleimide, N-butylmaleimide, N-phenylmaleimide, and N-carbamylmaleimide were obtained. On the basis of analysis of the product composition at various monomer feeds the relative reactivity of maleic anhydride and maleimides in these reactions is compared and the influence of the structure of thesemonomers on the rate of some chain growth reactions is discussed.     

Polymerizable Tautomers. VII. Radical Copolymerization of Ethyl 3-oxo-4-Pentenoate and Ethyl 4-Methyl-3-oxo-4-Pentenoate with Methyl Methacrylate

Abstract

Ethyl 3-oxo-4-pentenoate (EAA) and ethyl 4-methyl-3-oxo-4-pentenoate (EMAA) exhibit the coexistence of the ketonic and enolic forms in most organic solvents. Radical copolymerizations of EAA and EMAA with methyl methacrylate (MMA) were carried out at 60 °C in various solvents, and monomer reactivity ratios were estimated. There are minor solvent effects on monomer reactivity ratios r_MMA in both EAA/MAA and EM A A/MM A systems. On the other hand, r_EAA and r_MMA values greatly change with the solvent: The values decrease with an increase in the ketonic fraction of the polymerizable tautomers (EAA and EMAA). Regression analysis of the monomer reactivity ratios with the solvatochromic parameters reveals that polarity of the solvent is the major factor governing the relative reactivity.