Supramolecular structure and electro‐optical properties of functionalized maleic anhydride copolymers

New amphiphilic maleic acid copolymers containing oxadiazole rings as pendent groups were synthesized. Most of them form excellent Langmuir‐Blodgett films. The polymers were characterized by UV/Vis‐ and fluorescence spectroscopy and show electroluminescent behavior in the green‐yellow light region.     

The molecular structure of SEBS grafted with maleic anhydride through ultrasound initiation

The molecular structure of SEBS grafted with maleic anhydride(SEBS-g-MAH) through ultrasound initiation was investigated by nuclear magnetic resonance(NMR). It can be confirmed that the grafting groups mainly exist on the terminus of the ultrasound initiated SEBS-g-MAH. However, it was difficult to detailedly confirm the block of the SEBS on which MAH is grafted through characterization of 1H-NMR due to the complex structure of the SEBS. Moreover, the temperaturedependent infrared spectra of the ultrasound initiated SEBS-g-MAH were also analyzed by the perturbation correlation moving window 2D(PCMW2D) correlation spectroscopy. It could confirm that the broken point existed at the joint between poly(ethylene-co-1-butene)(EB block) and polystyrene block(S block). Therefore, the grafting groups were attached to not only the S block but also the EB block. In addition, in order to well understand the aggregation structure of the ultrasound initiated SEBS-g-MAH, the possible grafting mechanism and aggregation model of the ultrasound initiated SEBS-g-MAH at room temperature were also proposed.     

Effect of the initial maleic anhydride content on the grafting of maleic anhydride onto isotactic polypropylene

A series of ¹³C‐enriched maleic anhydride grafted isotactic polypropylene samples were prepared in solution at 170 °C by changes in the initial maleic anhydride content. The NMR spectra of the samples showed that the signals of the maleic anhydride attached to the tertiary carbons of the isotactic polypropylene chains increased considerably with increasing maleic anhydride content, whereas the signals of the maleic anhydride on the radical chain ends (with a single bond) arising from β scission did not. On the other hand, the signals of the maleic anhydride on the radical chain ends with double bonds increased markedly with increasing maleic anhydride content, and this suggested that β scission could occur extensively after maleic anhydride was attached to the tertiary carbons. As a result, the molecular weight of the grafted polypropylene decreased significantly with increasing maleic anhydride content in this study. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5529–5534, 2005     

Grafting of maleic anhydride to n-eicosane

Maleic anhydride was grafted to the linear hydrocarbon, n-eicosane, at 165°C in the presence of the free radical initiator, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne. The anhydride has a low solubility in eicosane and a multiple addition procedure was adopted. Grafted product which separated from the reaction mixture was fractionated and analyzed. The fractions contained on average 2–5.5 anhydride units/eicosane residue. ¹H- and ¹³C-NMR studies show that the grafts consist of single succinic anhydride rings. At the concentrations of maleic anhydride chosen for homogeneous reaction ( < 0.02 M) and at 165°C, poly(maleic anhydride) is above its ceiling temperature, so that succinic anhydride radicals cannot add maleic anhydride to form polymer side chains. Instead, these radicals abstract hydrogen atoms to yield grafts consisting of single anhydride units.     

热重法测定高马来酸酐含量苯乙烯-马来酸酐共聚物的组成

高马来酸酐含量苯乙烯-马来酸酐共聚物(SMA)是一种具有优良耐热性、刚性和尺寸稳定性的新型高分子材料.由于SMA分子中含有极性很强、反应活性很高的酸酐官能团,所以它被广泛应用于涂料、粘合剂的改性剂、地板抛光的乳化剂、复合材料和颜料的分散剂、水处理剂等领域[1-5].     

Di­chloro­maleic anhydride

Although mol­ecules of the title compound, 3,4‐di­chloro‐2,5‐dihydro­furan‐2,5‐dione (di­chloro­maleic anhydride, C₄Cl₂O₃), (I), possess approximate non‐crystallographic C_2v symmetry, the two chlorine substituents deviate from the ring plane. Their deviations are in the same direction, but with values of 0.0356 (17) and 0.0167 (17) Å, they differ significantly in magnitude. The closest intermolecular contact is of 2.888 (2) Å between a carbonyl O atom and the C atom of a carbonyl group, with the O?C direction orthogonal to the C=O bond [O5?C2ⁱ=O2ⁱ 93.6 (2)°; symmetry code: (i) ? x, ?½ + y, z]. These contacts form infinite chains of mol­ecules running parallel to the crystallographic b direction.     

Copolymerization of styrene with acrylonitrile and maleic anhydride

The complex formation constants for styrene (donor)-acrylonitrile (acceptor) and styrene-maleic anhydride (acceptor) systems are found to be 0.19 ± 0.01 and 0.28 ± 0.01 l/mol (¹H NMR, CCl₄, 298 K); the same values are characteristic for three-component systems of these monomers. The calculated ΔH ₀ values (the AM1 method) for styrene-acrylonitrile (C₁) and styrene-maleic anhydride (C₂) complexes comprise ?1.24 and ?2.30 kJ/mol. Changes in charges on double bonds of complex-bonded molecules are in the range from 0.001 to 0.006 au. These values are typical of π-π complexes. By analyzing the composition and rate of bulk copolymerization (333 K, 0.03 mol/l AIBN), we have shown that two complexes are involved in chain propagation: r ₁ = $ k_{2C_1 } /k_{2C_2 } $ = 0.26 ± 0.015 and r ₂ = $ k_{3C_2 } /k_{3C_1 } $ = 4.17 ± 0.143.     

Radiation-induced solid-state copolymerization of maleic anhydride and acenaphthylene

Radiation-induced solid-state copolymerization of the maleic anhydride–acenaphthylene system was carried out for the purpose of studying the solid-state polymerization of vinyl compounds in a binary system. Melting point measurement confirmed that this binary monomer system forms a eutectic mixture in the solid state. The solid-state polymerization of these monomers proceeds at maximum rate at the eutectic composition, and the polymerization products consist of a mixture of polyacenaphthylene and 1:1 maleic anhydride–acenaphthylene alternating copolymer. Since the 1:1 copolymer was obtained in solution polymerization also and maleic anhydride did not homopolymerize in solid state, it is considered that the solid-state copolymerization of maleic anhydride and acenaphthylene occurs in a liquidlike state at the boundary of the two monomer crystals.     

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.     

Copolymerisation of maleic anhydride with electron-acceptor monomers

Copolymerisation of maleic anhydride with tert.-butyl methacrylate and trimethylsilyl methacrylate was studied. Both monomers form random copolymers with maleic anhydride and in both cases the acceptor monomer is incorporated preferentially into the copolymer. Maleic anhydride which does not homopolymerise has reactivity ratios of approximately zero. The esters have reactivity ratios of 12.8 for trimethylsilyl methacrylate and 2.95 for tert.-butyl methacrylate. Thermal behavior and molar masses were investigated as a function of composition. Conditions for hydrolysis of the trimethylsilyl ester groups to give free acid groups have been established.     

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.     

Photoinduced polymerization of maleic anhydride in dioxane

Maleic anhydride (MAn) was irradiated with ultraviolet light in dioxane at 35°C without initiator, and predominantly a MAn oligomer was obtained with a small quantity of cyclic dimer of MAn. Mass spectrometric, NMR, and elementary analysis investigation of the oligomer showed that it is composed of about four MAn units and one dioxane molecule per molecule.     

Reactions of furfuryl alcohols with maleic anhydride

The reactions of some furfuryl alcohols with maleic anhydride have been reinvestigated and, for the first time, conditions defined for the production of intramolecular Diels-Alder adducts. In basic conditions these adducts yield phthalides in high yields.