Copolymerization of vinyl cyclohexane and α-methyl vinyl cyclohexane with acrylonitrile

Copolymerization of vinyl cyclohexane and α-methyl vinyl cyclohexane with acrylonitrile in the presence of a complexing agent AlEtCl₂ results in the formation of alternate copolymers. In the copolymerization of vinyl cyclohexane with acrylonitrile the copolymer composition depends on the ratio of acrylonitrile to AlEtCl₂. If this ratio is unity, alternating copolymers of the composition 1:1 are formed; with a ratio greater than unity statistical copolymers that contain more than 50% acrylonitrile units are produced. The ¹H-NMR spectroscopy measurements indicate that the interaction between the comonomers and the complexing agent leads to the formation of ternary donor–acceptor complexes of equimolar composition. The equilibrium constants of these complexes at ?60°C have been determined. The effects of temperature, nature of solvent and dilution on the yield, and composition of the copolymers of vinyl cyclohexane with acrylonitrile formed have been studied. By lowering the temperature the yield of copolymers increases but their composition remains equimolar. An increase in the polarity of the medium results in an increase in copolymer yield, whereas the yield decreases if the reaction is conducted in a donor-solvent medium. Dilution of the reaction mixture disrupts the alternation of units in the macrochain of copolymers. The kinetic pecularities of copolymerization have been investigated. The linear dependence of the copolymerization rate on the product of comonomer concentration is observed. The rate of copolymerization is proportional to the square root of the incident light intensity. Various additions of radical type and irradiation accelerate the process of copolymerization. The mechanism of alternating copolymerization of vinyl cyclohexane monomers with acrylonitrile in the presence of AlEtCl₂ is discussed in terms of homopolymerization of the comonomer complex.     

Copolymers from Castor Oil Prepolymers (COP). 1. Copolymerization of Acrylonitrile with COP

The copolymerization of castor oil prepolymer (COP) was attempted with vinyl monomers in the presence of a free radical initiator at 75°C. It was found that acrylonitrile copolymerizes with COP in good yield, The copolymers were yellow brown in color and were soluble in hot dimethylformamide. The percentage composition of the copolymers was determined by the nitrogen of the copolymers. Their reactivity ratios were determined to be r₁ = 0.53, r₂ = 1.53.     

Asymmetric selective copolymerization of propylene oxide with d-camphoric acid anhydride

The ring-opening copolymerization of propylene oxide with d-camphoric acid anhydride [α]_D ?3.4° was carried out with diethylzinc and triethylamine as catalysts. It was found that the products were alternating copolymers which were optically active. The optical rotatory dispersion curves were found to fit a simple Drude equation having a λ_c value of 201 mμ. The specific rotation increased with increasing intrinsic viscosity of the product. The propylene oxide recovered from the polymerization system was optically active. Its specific rotation increased with increasing polymerization time. It is thought that the asymmetric selective copolymerization of propylene oxide is caused by the influence of the optically active camphoryl group of the polymer end.     

HELIX SENSE-SELECTIVE COPOLYMERIZATION OF TRIPHENYLMETHYL METHACRYLATE WITH CHIRAL ANIONIC INITIATORS

Optically active copolymers of pairs of three monomers, triphenyl (methyl methacrylate)and one or two pyridyl substituted methyl methacrylate homologues, were obtained by helix-sense-selective copolymerization using complexes of organolithium with chiral ligand as anionicinitiators in toluene at low temperature. The copolymers obtained with (-)-sparteine (Sp) and(S,S)-(+)-and (R, R)-(-)-2, 3-dimethoxy-1, 4-bis (dimethylamino) butanes((+)-and (-)-DDB) complexes of organolithium showed low optical activity, but PMP complex with N, N-diphenylethyleneamine monolithium amide (PMP-DPEDA-Li) was effective in synthesizingcopolymers of high optical rotation ([α]_D~(25) about+320～1370°)which were comparable to thoseof relative homopolymers with one-handed helical structure.     

Donor-acceptor complexes in copolymerization. L. Preparation and microstructure of chlorine-containing alternating conjugated diene–acceptor monomer copolymers

Neighboring monomer units cause significant shifts in the infrared absorption peaks attributed to cis- and trans-1,4 units in conjugated diene-acceptor monomer copolymers. Conjugated diene-maleic anhydride alternating copolymers apparently have a predominantly cis-1,4-structure, while alternating diene-SO₂ copolymers have a predominantly trans-1,4 structure. Alternating copolymers of butadiene, isoprene, and pentadiene-1,3 with α-chloroacrylonitrile and methyl α-chloroacrylate, prepared in the presence of Et_1.5AlCl_1.5(EASC), have trans-1,4 unsaturation. Alternating copolymers of chloroprene with acrylonitrile, methyl acrylate, methyl methacrylate, α-chloroacrylonitrile, and methyl α-chloroacrylate prepared in the presence of EASC-VOCl₃ have trans-1,4 configuration. The reaction between chloroprene and acrylonitrile in the presence of AlCl₃ yields the cyclic Diel-Alder adduct in the dark and the alternating copolymer under ultraviolet irradiation. The equimolar, presumably alternating, copolymers of chloroprene with methyl acrylate and methyl methacrylate undergo cyclization at 205°C to a far lesser extent than theoretically calculated, to yield five and seven-membered lactones. The polymerization of chloroprene in the presence of EASC and acetonitrile yields a radical homopolymer with trans-1,4 unsaturation.     

Helix‐sense‐selective copolymerization of triphenylmethyl methacrylate with chiral 2‐isopropenyl‐4‐phenyl‐2‐oxazoline

The asymmetric induction leading to a one‐handed helix was investigated in the anionic and radical copolymerization of triphenylmethyl methacrylate (TrMA) and (S)‐2‐isopropenyl‐4‐phenyl‐2‐oxazoline ((S)‐IPO), and highly isotactic copolymers with a reasonable optical activity were obtained. In the anionic copolymerization, the optical activity of the obtained copolymers depended on the polarity of solvents, and a highly optically active copolymer was produced in the copolymerization in toluene. The chiral oxazoline monomer functioned not only as a comonomer but also as a chiral ligand to endow the polymer with large negative optical rotation in the copolymerization with TrMA. The copolymers with small positive optical rotation were obtained in THF, indicating that IPO unit may work only as the chiral monomer that dictates the helical sense via copolymerization with TrMA. The isotacticity of the obtained copolymers depended on the contents of TrMA units in the copolymers, but was almost independent of the solvent for copolymerization. In the radical copolymerization, the obtained copolymers exhibited small optical activities. It seemed that the chiral monomer cannot induce one‐handed helical structure of TrMA sequences even if the sequences probably have a high isotacticity. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 441–447     

Copolymerization of optically active N-bornylmaleimide with vinyl monomers

Optically active N-bornylmaleimide (NBMI) was copolymerized with styrene, methyl methacrylate, and vinylidene chloride with a free-radical catalyst to obtain optically active copolymers. The monomer reactivity ratios for the radical copolymerization of NBMI (M₂) with styrene, methyl methacrylate, and vinylidene chloride were: ST-NBMI, r₁ = 0.13, r₂ = 0.05; MMA-NBMI, r₁ = 2.02, r₂ = 0.16; VCl₂-NBMI, r₁ = 1.15, r₂ = 0.47. The Q-e values for NBMI were Q₂ = 0.48 and e₂ = +1.47. The specific rotation and optical rotatory dispersion of these copolymers were measured. The correlation between the specific rotation and composition of these copolymers was not linear. The value of λ_c for each copolymer was independent of the copolymer composition and the comonomer, being 260 mμ for the St-NBMI system, 262 mμ for the MMA-system, and 260 mμ for the VCl₂-NBMI system. The effects of solvents and temperature on the specific rotation of these copolymers were investigated.     

Alternating copolymerization of benzofuran with crotononitrile and α-chloroacrylonitrile

The copolymerizations of benzofuran with α,α- or α,β-disubstituted acrylic monomers were studied. The alternating copolymer of benzofuran and crotononitrile was prepared in the presence of an excess amount of crotononitrile with respect to benzofuran, ethylaluminum dichloride, and azobisisobutyronitrile. The intrinsic viscosity of copolymers was 0.1–0.2 dl/g. Crotononitrile is known to possess a polar carbon–carbon double bond from ¹³C-NMR spectroscopy but the alternating copolymerizability with benzofuran is low. It was found that the order of alternating copolymerizability of acrylic monomers is as follows: This fact may be attributed to the steric hindrance of the β-methyl of crotononitrile. The induced shifts by complexation with ethylaluminum dichloride on ¹³C-NMR spectra of the two isomers of crotononitrile are almost same but the copolymerizability of cis isomer is higher than that of trans isomer. α-Chloroacrylonitrile shows the highest alternating copolymerizability with benzofuran in the presence of weak Lewis acid such as ethoxyaluminum chloride. Alternating copolymerizability of acrylic monomers seems to be in proportion to their e value. The reactivity of cis- and trans-crotononitrile may depend on the nature of a ternary complex composed of aluminum compound, crotononitrile, and benzofuran.     

Alternating copolymerization of isoprene and butadiene with acrylonitrile

Copolymerizations of acrylonitrile and isoprene or butadiene were carried out in the presence of a new catalytic system containing Cr(O-tert-Bu)₄ and AlEtCl₂. It was found that the copolymer compositions have a highly alternating structure, even with varying feed ratios of monomer. The nuclear magnetic resonance spectra of the copolymers obtained with this catalytic system were observed and are discussed in terms of the alternation.     

Greffage radiochimique de l'acrylonitrile sur le poly(methacrylate de methyle)

The radiation-induced polymerization of acrylonitrile with dissolved PMMA exhibits kinetics similar to those found with the pure monomer. The addition of PMMA to the monomer at first leads to an increase in polymerization rate; a maximum in rate is observed for 60 per cent acrylonitrile in the mixture. The unreacted PMMA was quantitatively extracted by toluene from the reaction mixture. In contrast, polyacrylonitrile could not be separated from the graft copolymer by fractional precipitation, presumably due to association of the graft copolymer with the precipitated homopolymer. The free radical yield of PMMA “G_R effective” derived from these results was found to be 8 to 10 in mixtures containing small amounts of monomer. It rapidly decreased as the monomer concentration increased.The solubilities of the graft copolymers were characterized by the precipitation γ determined for several precipitants in DMF solutions. A maximum in solubility was found for copolymers containing 25 to 35 per cent acrylonitrile in DMF-alcohol mixtures. The glass transition temperatures (T_g) of the graft copolymers were measured using a penetrometer. T_g increased with the MMA content in the copolymer. A small minimum of T_g appeared to exist for copolymers containing 90 per cent acrylonitrile.     

Preparation of Graft Copolymers By Means of Uv Photolysis of Poly(Methyl Vinyl Ketone) and Reverse Osmosis Performance of the Membranes from the Oximes of the Copolymers

ABSTRACT

An attempt was made to prepare a graft copolymer consisting of poly(methyl vinyl ketone) (PMVK) as a backbone chain and polyacrylonitrile, poly(4-vinylpyridine), or polystyrene as a graft chain by UV irradiation of a solution of PMKV in the presence of acrylonitrile, 4-vinylpyridine, or styrene. the influence of reaction conditions on the yield, composition, and viscosity of the resulting graft copolymers was investigated. It was suggested from NMR and gel permeation chromatography that those graft copolymers contained a high molecular weight fraction of narrow distribution and block copolymers as well. the reverse osmosis membranes derived from the oxime and amidoxime of the graft copolymers showed a characteristic performance of exhibiting a maximal difference between rejections against NaCl and CoCl₂ at a certain addition ratio of crosslinking agent, which was not observed in the membranes from copolymers by conventional radical copolymerization. the relationship between these phenomena and the branching structure of the graft copolymers was discussed.     

Controlled radical copolymerization of β‐pinene and acrylonitrile

The feasibility of the radical copolymerization of β‐pinene and acrylonitrile was clarified for the first time. The monomer reactivity ratios evaluated by the Fineman–Ross method were r_β‐pinene = 0 and r_{acrylonitrile} = 0.66 in dichloroethane at 60 °C with AIBN, which indicated that the copolymerization was a simple alternating copolymerization. The addition of the Lewis acid Et₂AlCl increased the copolymerization rate and enhanced the incorporation of β‐pinene. The first example for the synthesis of an almost perfectly alternating copolymer of β‐pinene and acrylonitrile was achieved in the presence of Et₂AlCl. Furthermore, the possible controlled copolymerization of β‐pinene and acrylonitrile was then attempted via the reversible addition–fragmentation transfer (RAFT) technique. At a low β‐pinene/acrylonitrile feed ratio of 10/90 or 25/75, the copolymerization with 2‐cyanopropyl‐2‐yl dithiobenzoate as the transfer agent displayed the typical features of living polymerization. However, the living character could be observed only within certain monomer conversions. At higher monomer conversions, the copolymerizations deviated from the living behavior, probably because of the competitive degradative chain transfer of β‐pinene. The β‐pinene/acrylonitrile copolymers with a high alternation degree and controlled molecular weight were also obtained by the combination of the RAFT agent cumyl dithiobenzoate and Lewis acid Et₂AlCl. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2376–2387, 2006     

Alternating copolymer of styrene–acrylonitrile obtained with vanadium-based complex catalyst in presence of monomers

Vanadium-based catalyst complexes prepared in the presence of monomers have been used for the copolymerization of styrene and acrylonitrile. VOCl₃–Al(i-C₄H₉)₃ catalyst system seems to yield an alternating copolymer. The copolymers are easily soluble in DMF and have low softening points.     

Synthesis of highly photostable blue-emitting 1,8-naphthalimides and their acrylonitrile copolymers

Two novel highly photostable blue-emitting 1,8-naphthalimides, containing active fragments of a hindered amine radical scavenger and an s-triazine UV absorber were designed as multifunctional additives capable of simultaneous fluorescent brightening and photostabilization of polymers. Their light absorption and fluorescence properties have been determined and discussed. The ability of the combined fluorescent brighteners to copolymerize with acrylonitrile was demonstrated by obtaining acrylonitrile copolymers with an intense blue fluorescence. Photodegradation of the new fluorophores and their influence on the photostability of the fluorescent copolymers have been studied and compared to other similar 1,8-naphthalimides, not containing either UV absorber or hindered amine fragment in their molecules as well as not containing both of them. Novel fluorophores showed the best photostability in both solution and polymer. A significant photostabilizing effect towards photodegradation of polyacrylonitrile was found.     

Fluorescent 2-(2′-hydroxybenzofuran)benzoxazole (HBBO) borate complexes: synthesis,optical properties,and theoretical calculations

The multi-step synthesis, structural and optical properties of original luminescent borate complexes derived from 2-(2′-hydroxybenzofuran)benzoxazole (HBBO) are reported. Functionalization at position 3 of the benzofuran ring was readily achieved through an electrophilic cyclization key step followed by a Sonogashira cross-coupling reaction. The optical properties of the resulting boron difluoride dyes highlight different photophysical behaviors depending on the nature of the substitution at position 3 of the benzofuran core (^tBu-phenylacetylene or NⁿBu₂-phenylacetylene). The NⁿBu₂-phenylacetylene moiety favors a sizeable intramolecular charge transfer as evidenced by a strong solvatochromism; a feature further confirmed by ab initio calculations.     

Carbon-13 NMR. The analysis of the relaxation times T1 of benzofuran and of a series of its methyl derivatives. Correlations between molecular motions and structural properties

Carbon-13 relaxation times (T₁) and nuclear Overhauser enhancements (η) have been measured for benzofuran and a series of its methyl derivatives. The contributions of dipolar (T₁ ^DD) and spin rotation (T₁^SR) mechanisms have both been determined. The temperature dependence of T₁ has been studied. The relationships between molecular motions and structural properties have been emphasized. The overall motional anisotropy of the benzofuran molecule is increased by substitution in positions 2 and 5. The internal rotation of a methyl group may change depending on its position in the molecule and on the influence of other methyl groups in its close neighbourhood.     

含金鸡纳碱的光活性聚合物──Ⅰ．金鸡纳碱／丙烯酰胺共聚物的合成与表征

研究了金鸡纳碱与丙烯酰胺的自由基共聚反应。发现在氯仿／乙醇混合溶剂中采用硫酸奎宁作为金鸡纳碱共聚单体可以合成收率和金鸡纳碱含量均较高的新型水溶性共聚物。对共聚物用元素分析、核磁共振、粘度和旋光度测定等方法进行表征，发现在假定丙烯酰胺链节为非光活性的条件下共聚物中金鸡纳碱链节的比旋光度随聚合配方中金鸡纳碱含量的增加而增加。     

Copolymers containing a spiro orthoester moiety that undergo no shrinkage during cationic crosslinking

A spiro orthoester with an exomethylene group (exoSOE) was radically copolymerized with acrylonitrile or vinyl acetate at several feed ratios to obtain the corresponding copolymers having spiro orthoester moieties in the side chain. The obtained copolymers could be crosslinked via the double ring‐opening polymerization of the spiro orthoester moieties in their side chain by a treatment with BF₃OEt₂. The volume changes upon the crosslinking of the copolymers were evaluated by density measurements with a micromeritics gas pycnometer. The copolymers experienced less than 1% volume expansion instead of volume shrinkage during typical cationic crosslinking, regardless of the copolymer compositions. Negligible shrinkage was observed during the thermal cationic crosslinking of a film cast from a nitrobenzene solution of the copolymers containing a benzylthiophenium salt as a thermally latent cationic initiator. The constantly low volume changes during the crosslinking of the copolymers from exoSOE probably depended on the almost zero volume change during the cationic polymerizations of spiro orthoester derivatives. This indicates that exoSOE is an effective monomer for crosslinkable polymers without volume changes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3666–3673, 2006     

新型光活性串型液晶共聚物合成与表征

以对苯二甲酰氯,２ ,５ 二［４ （（Ｓ） ２ 甲基丁氧基） 苯甲酰氧基］ 对苯二酚和己二醇为单体,采用溶液共缩聚的方法,合成了一系列新的光活性串型液晶共聚物．共聚物通过ＧＰＣ、ＤＳＣ、ＴＧ、ＷＡＸＤ、偏光显微镜和旋光仪等方法表征．发现所有的共聚物加热至各自的熔点以上都能形成液晶态,在液晶态可以观察到沙地织构或破碎焦锥织构．通过变温Ｘ 射线衍射证明它们为手性近晶Ｃ（Ｓ＊Ｃ） 相．所有共聚物的熔点（ Ｔｍ） 和液晶态清亮点（ Ｔｉ） 随共聚物中己二醇用量的改变呈规律性变化．共聚物有很高的旋光性,在合成反应中旋光性保持．     

Donor-Acceptor Complexes in Copolymerization. XXXV. Alternating Diene-Dienophile Copolymers. 3. Copolymerization of cis- and trans-1, 3-Pentadiene with Maleic Anhydride and Acrylonitrile… AlEt1.5CI1.5

Abstract

The copolymerization of the cis or trans isomers of 1,3-pentadiene with maleic anhydride in the presence of a peroxide catalyst yields identical equimolar, alternating copolymers in which the pentadiene units have a cis-1, 4 configuration (IR, NMR). The copolymerization of the cis or trans isomers of 1, 3-pentadiene with acrylonitrile in the presence of ethyl aluminum sesquichloride yields identical equimolar, alternating copolymers in which the pentadiene units have a trans-1,4 configuration (IR, NMR). Although the trans isomer forms cyclic adducts with both maleic anhydride and acrylonitrile, the cis isomer does not undergo the Diels-Alder reaction with these dienophlles. The formation of identical copolymers from cis- and trans-1, 3-pentadiene is attributed to isomerization of the diene-dienophile charge transfer complex in the excited state, resulting in the generation of the same homopolymerizable exciplex from both isomers.