Radical Copolymerization of Vinylidene Chloride with 3(2-Methyl)-6-methylpyridazinone in Several Solvents

The radical copolymerization of vinylidene chloride (Vc, M₁) with 3(2-methyl)-6-methylpyridazinone (I, M₂) was carried out in benzene, ethanol, phenol, and acetic acid at 60 and 80°C. The monomer reactivity ratios were found to vary with the reaction conditions. The linear correlationships were obtained by plotting the values of log r₁ against those of ^V C[dbnd]O and ^V C[dbnd]C of monomers determined in the solvents.     

Radiation copolymerization of vinylene carbonate with isobutyl vinyl ether

The radiation-induced copolymerization of vinylene carbonate (M₁) with isobutyl vinyl ether (M₂) has been investigated over the temperature range of 40–80°C. The monomer reactivity ratios r₁ and r₂ were determined to be 0.118 and 0.148, respectively, and an activation energy of 7.6 kcal/mole (31.8 kJ/mole) was calculated for the copolymerization process.     

Copolymerization of 4-cyclopentene-1,3-dione with p-chlorostyrene and vinylidene chloride

The copolymerization of 4-cyclopentene-1,3-dione (M₂) with p-chlorostyrene and vinylidene chloride is reported. The copolymers were prepared in sealed tubes under nitrogen with azobisisobutyronitrile initiator. Infrared absorption bands at 1580 cm.^?1 revealed the presence of a highly enolic β-diketone and indicated that copolymerization had occurred. The copolymer compositions were determined from the chlorine analyses and the reactivity ratios were evaluated. The copolymerization with p-chlorostyrene (M₁) was highly alternating and provided the reactivity ratios r₁ = 0.32 ± 0.06, r₂ = 0.02 ± 0.01. Copolymerization with vinylidene chloride (M₁) afforded the reactivity ratios r₁ = 2.4 ± 0.6, r₂ = 0.15 ± 0.05. The Q and e values for the dione (Q = 0.13, e = 1.37), as evaluated from the results of the vinylidene chloride case, agree closely with the previously reported results of copolymerization with methyl methacrylate and acrylonitrile and confirm the general low reactivity of 4-cyclopentene-1,3-dione in nonalternating systems.     

Cationic copolymerization of 2-methylene-5,5-dimethyl-1,3-dioxane with 2-methylene-1,3-dioxolane and 2-methylene-1,3-dioxane

Copolymers of the cyclic ketene acetals, 2-methylene-5,5-dimethyl-1,3-dioxane, 3 , (M₁) with 2-methylene-1,3-dioxolane, 4 , (M₂) or 2-methylene-1,3-dioxane, 5 , (M₂), were synthesized by cationic copolymerization. An experimental method was designed to study the reactivity of these very reactive and extremely acid sensitive cyclic ketene acetal monomers. The reactivity ratios, calculated using a computer program based on a nonlinear minimization algorithm, were r₁ = 6.36 and r₂ = 1.25 for the copolymerization of 3 with 4 , and r₁ = 1.56 and r₂ = 1.42 for the copolymerization of 3 with 5. FTIR and ¹H-NMR spectra when combined with the values of r₁ and r₂ showed that these copolymers were formed by a cationic 1,2-polymerization (ring-retained) route. Furthermore the tendency existed to form very short blocks of M₁ or M₂ within the copolymers. Cationic copolymerization of cyclic ketene acetals have the potential to be used for synthesis of novel polymers. © 1996 John Wiley & Sons, Inc.     

Silyl enol ethers as monomer. III. Radical polymerization and copolymerizations of 2-trimethylsilyloxy-1,3-butadiene and desilylation of the resulting polymers

2-Trimethylsilyloxy-1,3-butadiene (TMSBD), the silyl enol ether of methyl vinyl ketone, was homopolymerized with a radical initiator to afford polymers with a molecular weight of ca. 10⁴. Radical copolymerizations of TMSBD with styrene (ST) and acrylonitrile (AN) in bulk or dioxane at 60°C gave the following monomer reactivity ratios: r₁ = 0.64 and r₂ = 1.20 for the ST (M₁)–TMSBD (M₂) system and r₁ = 0.036 and r₂ = 0.065 for the AN (M₁)–TMSBD (M₂) system. The Q and e values of TMSBD determined from the reactivity ratios for the former copolymerization system were 2.34 and ?1.31, respectively. The resulting polymer and copolymers were readily desilylated with hydrochloric acid or tetrabutylammonium fluoride as catalyst to yield analogous polymers having carbonyl groups in the polymer chains.     

Intramolecular charge transfer complexes. VIII. Poly[N-(2-hydroxyethyl) carbazolyl acrylate-co-2,4-dinitrophenyl methacrylate]

Radical copolymerization of N-(2-hydroxyethyl) carbazolyl acrylate (HECA, M₁) with 2,4-dinitrophenyl methacrylate (DNPM, M₂) can be described by a simple terminal mechanism having the relative reactivities r₁ = 0.14, r₂ = 1.10 (at 60°C); 0.28, 0.96 (80°C); and 0.41, 0.79 (100°C), respectively. The dependence of the reactivity ratio values on copolymerization temperature, analyzed by Arrhenius equation, takes place mainly through the frequency factor. The copolymers obtained are intramolecular charge transfer complexes. The intramolecular interaction is evidenced by the shift of the aromatic protons from the DNPM structural unit in the copolymers' ¹H-NMR (nuclear magnetic resonance) spectra. This shift depends on sequence distribution and chain conformation, but is not affected by the copolymerization temperature.     

Solution copolymerization of styrene and 2-hydroxyethyl mechacrylate.

The rate of solution copolymerization of styrene (M₁) and 2-hydroxyethyl methacrylate (M₂) was investigated by dilatometry. N,N-dimethyl formamide, toluene, isopropyl alcohol, and butyl alcohol were used as solvents. Polymerization was initiated by α,α′-azobisisobutyronitrile at 60°C. The initial copolymerization rate increased nonlinearly with increasing 2-hydroxyethyl methacrylate (HEMA)/styrene ratio. The copolymerization rate was promoted by solvents containing hydroxyl groups. Two different approaches were used for the prediction of copolymerization rates. The relationships proposed for the copolymerization rates calculation involve the effects of the total monomer concentration, mole fraction of HEMA, and of the solvent type. Different reactivity ratios were found in polar and nonpolar solvents: r₁ = 0.53, r₂ = 0.59 in N,N-dimethyl formamide, isopropyl alcohol and n-butyl alcohol; r₁ = 0.50, r₂ = 1.65 in toluene. The usability of these reactivity ratios was confirmed by batch experiments.     

二烷基锡聚合物的研究——Ⅲ.顺丁烯二酸二丁基锡酯与丙烯酸甲酯、丙烯酸丁酯的共聚合

Benzoyl peroxide (BPO) was used for initiator in copolymerization of dibutyltin maleate (DBTM, M₂) with methyl acrylate (MA, M₁) in benzene and the reactivity ratios of copolymerization r1 and r2 were found to be 12.67 and 0.03, respectively. But in copolymerization of DBTM (M₂) with butyl acrylate (BA, M₁) r1 and r2 were 11.1 and 0> respectively. The cc-polymerization conditions, such as amount of initiator, ratios of monomers and addition method of initiator were examined. Copolymers were characterized by ¹H-NMR,IR,elemental and TG analyses. MA-DBTM copolymer is a white and brittle solid, while BA-DBTM copolymer is a transparent elastomer at room temperature.     

Radical homo- and copolymerizations of methyl α-trifluoroacetoxyacrylate

Radical homo- and copolymerizations of methyl α-trifluoroacetoxyacrylate (MTFAA) are studied by using azo initiators at 40 and 60°C. The rate of the homopolymerization of MTFAA was lower than that of methyl α-acetoxyacrylate. Monomer reactivity ratios (r), and Q and e values were estimated to be r₁ = 0.03, r₂ = 0.27, Q₁ = 0.65, and e₁ = 1.38 from the copolymerization of MTFAA (M₁) and styrene (M₂) at 60°C. Preferential crosspropagation was observed in particular in the copolymerization of MTFAA and α-methylstyrene. The influence of replacing the hydrogens of the acetoxy moiety of the acyloxyacrylate with the fluorines upon the copolymerization reactivity is discussed on the basis of the ¹³C-NMR chemical shift of various acyloxyacrylates. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3537–3541, 1997     

Spontaneous alternating copolymerization of N-phenylmaleimide with ethyl α-phenylacrylate

The spontaneous copolymerization of N-phenylmaleimide (NPMI) (M₁) with ethyl α-phenylacrylate (EPA)(M₂) were carried out in dioxane at 85°C. A high alternating tendency was observed. The monomer reactivity ratios were r₁ = 0.07 ±0.01 and r₂ = 0.09 ± 0.02. The maximum copolymerization rate and molecular weight occurs at 70–80 mol% (M₁) in feed ratio. The spontaneous alternating copolymerization is considered to be carried out via a contact-type charge transfer complex (CTC) formed between the monomers. Thermogravimetric analyses (TGA) indicate the resulting copolymers have high thermal stability. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 2927–2931, 1998     

Effect of Solvent on the Radical Copolymerizability of Styrene with 3(2-Methyl)-6-methylpyridazinone

Abstract

The radical copolymerization of styrene (St, M₁) with 3(2-methyl)-6-methylpyridazinone (I, M₂) has been carried out in several p-substltuted phenols at 60 and 70°C. Monomer reactivity ratios (r₁) and activation parameters of copolymerization were found to be affected by phenols. The values of the activation energy (δδE?) and entropy (δδS?) increased with the increase of the interaction of I with the solvents. Linear relationships were observed between the [sgrave]-values of p-substituents of phenols and the values of log 1/r₁ and also of δδE? and δδS?. The radical copolymerization of St (M₁) with 6-substituted 3(2-methyl)-pyridazinone was also carried out.     

Copolymerization of styrene and methyl methacrylate. Reactivity ratios from conversion–composition data

A method for the determination of reactivity ratios from conversion–composition data has been outlined. The conversion–composition changes during the copolymerization of styrene (M₁) and methyl methacrylate (M₂) have been studied at 60°C. By a method of graphical intersection, the integrated form of Skeist's equation has been used to determine the reactivity ratios (r₁ = 0.54 ± 0.02 and r₂ = 0.50 ± 0.06) in reasonably good agreement with values reported in the literature. The area of intersection was used as a measure of the precision of the data.     

Copolymerization of 2-Hydroxypropyl Methacrylate with Alkyl Met hacrylates

2-Hydroxypropyl methacrylate (2-HPMA) has been copolym-erized with ethyl methacrylate (EMA), n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (EHMA) in bulk at 60°C using benzoyl peroxide as initiator. The copolymer composition has been determined from the hydroxyl content. The reactivity ratios have been calculated by the Yezrielev, Brokhina, and Raskin method. For copolymerization of 2-HPMA (M₁) with EMA (M₂), the reactivity ratios are r₁ = 1.807 ± 0.032 and r₂ = 0.245 ± 0.021; with BMA (M₂) they are n = 2.378 ± 0.001 and r₂ = 0.19 ± 0.01; and with EHMA the values are r₁ = 4.370 ± 0.048 and r₂ = 0.103 ± 0.006. Since reactivity ratios are the measure of distribution of monomer units in copolymer chain, the values obtained are compared and discussed. This enables us to choose a suitable copolymer for synthesizing thermoset acrylic polymers, which are obtained from cross-linking of hydroxy functional groups of HPMA units, for specific end-uses.     

Copolymerization of 2-Hydtoxypropyl Methacrylate with Alkyl Methacrylates

2-Hydroxypropyl methacrylate (2 HPMA) has been copolym-erized with ethyl methacrylate (EMA), n-butyl methacrylate (BMA), and 2-ethylhexyl methacrylate (EHMA) in bulk at 60°C using benzoyl peroxide as initiator. The copolymer composition has been determined from the hydroxyl content. The reactivity ratios have been calculated by the YBR method. For copolymerization of 2-HPMA (M₁) with EMA (M₂), the reactivity ratios are: r₁=1.807 ± 0.032, r₂=0.245 ± 0.021; with BMA (M₂) they are r₁=2.378 ± 0.001, r₂=0.19 ± 0.01; and with EHMA the values are r₁=4.370 ± 0.048, r₂=0.103 ± 0.006. Since the reactivity ratios are the measure of distribution of monomer units in a copolymer chain, the values obtained are compared and discussed. This enables us to choose a suitable copolymer for synthesizing thermoset acrylic polymers, which are obtained from cross-linking of hydroxy functional groups of HPMA units, for specific end uses.     

Alternating polyampholytes prepared by hydrolysis of copolymer of maleic anhydride and N-vinylsuccinimide

Alternating polyampholytes (MA-VA) containing two acidic groups and one basic group were prepared by the copolymerization of maleic anhydride (M₁) and N-vinylsuccinimide (M₂) at 60°C with AIBN as the initiator, followed by acid hydrolysis with 1N hydrochloric acid at 140°C for 24 hr. The monomer reactivity ratios r₁ and r₂ are 0.025 and 0.06, respectively. The structure of polymers was discussed on the basis of the data of their elementary, infrared (IR), and thermal analyses and the binding ability of heavy metal ion. Polyampholytes were soluble in strong acidic and basic media but were precipitated in the pH range 3–4. An isoelectric point at pH 3 was determined by potentiometric titration and the turbidimetric method. By thermal treatment above 205°C the polyampholyte turned quantitatively into a cyclized lactam. This suggests that the polyampholyte MA–VA has an intramolecular hydrogen bond between the amino and γ-carboxyl groups. The binding of Cu²⁺ and Hg²⁺ by the polyelectrolyte was evaluated by equilibrium dialysis.     

Copolymerization of 2-sulfoethyl methacrylate

Copolymers of 2-sulfoethyl methacrylate, (SEM) were prepared with ethyl methacrylate, ethyl acrylate, vinylidene chloride, and styrene in 1,2-dimethoxyethane solution with N,N′-azobisisobutyronitrile as initiator. The monomer reactivity ratios with SEM (M₁) were: vinylidene chloride, r₁ = 3.6 ± 0.5, r₂ = 0.22 ± 0.03; ethyl acrylate, r₁ = 3.2 ± 0.6, r₂ = 0.30 ± 0.05; ethyl methacrylate, r₁ = 2.0 ± 0.4, r₂ = 1.0 ± 0.1; styrene, r₁ = 0.6 ± 0.2, r₂ = 0.37 ± 0.03. The values of the copolymerization parameters calculated from the monomer reactivity ratios were e = +0.6 and Q = 1.4. Comparison of the monomer reactivities indicates that SEM is similar to ethyl methacrylate with regard to copolymerization reactivity in 1,2-dimethoxyethane solution. The sodium salt of 2-sulfoethyl methacrylate, SEM^?Na^⊕, was copolymerized with 2-hydroxyethyl methacrylate (M₂) in water solution. Reactivity ratios of r₁ = 0.7 ± 0.1 and r₂ = 1.6 ± 0.1 were obtained, indicating a lower reactivity of SEM^?Na^⊕ in water as compared to SEM in 1,2-dimethoxyethane. This decreased reactivity was attributed to greater ionic repulsion between reacting species in the aqueous medium.     

Copolymerization of Tri-n-butyltin Acrylate and Tri-n-butyltin Methacrylate Monomers with Vinyl Monomers Containing Functional Groups

A new approach to obtaining thermoset organotin polymers, which permits control of crosslinking site distribution and, through it, a better control of properties of organotin antifouling polymers, is reported. Tri-n-butyltin acrylate and tri-n-butyltin methacrylate monomers were prepared and copolymerized, by the solution polymerization method with the use of free-radical initiators, with several vinyl monomers containing either an epoxy or a hydroxyl functional group. The reactivity ratios were determined for six pairs of monomers by using the analytical YBR method to solve the differential form of the copolymer equation. For copolymerization of tri-n-butyltin acrylate (M₁) with glycidyl acrylate (M₂), these reactivity ratios were n = 0.295 ± 0.053, r₂ = 1.409 ± 0.103; with glycidyl methacrylate (M₂) they were r₁ = 0.344 ± 0.201, r₂ = 4.290 ± 0.273; and with N-methylolacrylamide (M₂) they were r₁ = 0.977 ± 0.087, r₂ = 1.258 ± 0.038. Similarly, for the copolymerization of tri-n-butyltin methacrylate (Mi) with glycidyl aery late (M₂) these reactivity ratios were r₁ = 1.356 ± 0.157, r₂ = 0.367 ± 0.086; with glycidyl methacrylate (M₂) they were r₁ = 0.754 ± 0.128, r₂ = 0.794 ± 0.135; and with N-methylolacrylamide (M₂) they were r₁ ?4.230 ± 0.658, r₂ = 0.381 ± 0.074. Even though the magnitude of error in determination of reactivity ratios was small, it was not found possible to assign consistent Q,e values to either of the organotin monomers for all of its copolymerizations. Therefore, Q,e values were obtained by averaging all Q,e values found for the particular monomer, and these were Q = 0.852, e = 0.197 for the tri-n-butyltin methacrylate monomer; and Q = 0.235, e = 0.401 for the tri-n-butyltin acrylate monomer. Since the reactivity ratios indicate the distribution of the units of a particular monomer in the polymer chain, the measured values are discussed in relation to the selection of a suitable copolymer which, when cross-linked with appropriate crosslinking agents through functional groups, would give thermoset organotin coatings with an optimal balance of mechanical and antifouling properties.     

Free Radical Copolymerization of N‐Cyclohexylmaleimide with Cyclohexene

The radical copolymerization of cyclohexene (M₁) and N‐cyclohexylmaleimide (M₂) was carried out with 2,2′‐azobis(isobutyronitrile) as an initiator in various solvents at 55°C. The copolymerization of cyclohexene with N‐cyclohexylmaleimide in chloroform, dioxane and benzene proceeded in a homogeneous system to give an alternating copolymer when the monomer of cyclohexene was over 40 mol% in the feed. It was found that the initial rate of the copolymerization (R_p), as well as the number‐average molecular weight of copolymers, were dependent on the monomer composition and was at maximum at about 30 mol% of cyclohexene in the feed. The effects of solvents on the R_p and reactivity ratios were also investigated in this copolymerization system. The copolymerization in dioxane produced a higher R_p than that in chloroform and benzene, and the monomer reactivity ratios were found to be r₁=0, r₂=0.032 in chloroform; r₁=0, r₂=0.065 in benzene and r₁=0, r₂=0.14 in dioxane, respectively.     

N-vinylpyrrolidone and 4-vinyl Benzylchloride Copolymers: Synthesis,Characterization and Reactivity Ratios

The copolymers prepared in this study by free radical copolymerization of N-vinylpyrrolidone (M ₂) with 4-vinylbenzylchloride (M ₁) using 2,2′-azobisisobutyronotrile (AIBN) initiator in 1,4-dioxane solvent at 70°C were characterized by FTIR, ¹H-NMR and ¹³C-NMR techniques. Polymer solubility was tested in both polar and nonpolar solvents. The thermal properties were studied by thermogravimetric analysis (TGA) and differential scanning calorimeter (DSC). Copolymer compositions were established by H¹-NMR spectra, while reactivity ratios of the monomers were computed using the linearization methods viz., Fineman-Ross (FR) (r ₁ = 1.67 and r ₂ = 0.67), Kelen-Tudos (KT) (r ₁ = 1.77 and r ₂ = 0.65) and extended Kelen-Tudos (EK-T) (r ₁ = 1.72 and r ₂ = 0.63) methods at lower conversion. Furthermore, reactivity ratios in nonlinear error-in-variables method (RREVM) also compute the reactivity ratios (r ₁ = 1.76 and r ₂ = 0.66); these are found to be in good agreement with each other. The distribution of monomer sequence along the copolymer chain was calculated using a statistical method based on the calculated reactivity ratios.     

Copolymerization of glycidyl methacrylate with alkyl acrylate monomers

A newer approach to obtaining acrylic thermoset polymers with adequate hydrophilicity required for various specific end uses is reported. Glycidyl methacrylate (GMA) was copolymerized with n-butyl acrylate (n-BA), isobutyl acrylate (i-BA), and 2-ethylhexyl acrylate (2-EHA) in bulk at 60°C. with benzoyl peroxide as free radical initiator. The copolymer composition was determined from the estimation of epoxy group. Reactivity ratios were calculated by the Yezrielev, Brokhina, and Roskin method. For copolymerization of GMA (M₁) with n-BA (M₂) the reactivity ratios were r₁ = 2.15 ± 0.14, r₂ = 0.12 ± 0.03; with i-BA (M₂) they were r₁ = 1.27 ± 0.06, r₂ = 0.33 ± 0.031; and with 2-EHA (M₂) they were r₁ = 2.32 ± 0.14, r₂ = 0.13 ± 0.009. The reactivity ratios were the measure of distribution of monomer units in a copolymer chain; the values obtained are compared and discussed.