Zakir M. O. Rzaev

Side-chain functionalization of polystyrene with maleic anhydride in the presence of lewis acids

Polystyrenes with different molecular weights were chemically modified with maleic anhydride by use of certain cationic catalysts of Lewis acid type (BF3·OEt2, AICI3, TiCL4, ZnCl2, FeCl3, and SnCl4) in chloroform. The effects of molecular weight of polystyrene, as well as type of Lewis acid used, on properties and structure of products were investigated. The interrelation between the molecular weight of polystyrene and content of carboxyl groups in the products was made. A direct relationship between the activity of catalyst used and the number of carboxyl groups was found. For characterization of side-chain functionalized polystyrene, fractional precipitation was applied which yielded carboxyl groups in all fractions. The carboxyl group concentrations were found to be the highest in the case of BF3·OEt2. Modified polystyrene samples containing COCHCHCOOH fragments in side chains are easily crosslinked at 140–150°C and by UV irradiation as proved by IR, DTA, and TGA analyses. Functionalized polymers obtained are characterized by their high thermostability, adhesion, and photosensitivity.

Complex-radical terpolymerization of glycidyl(methyl) methacrylates, styrene, and maleic anhydride

The ternary copolymerizations of glycidyl(methyl) methacrylates (GMA and MMA), styrene (St), and maleic anhydride (MA), considered as acceptor(A 1 )-donor-acceptor(A 2 ) systems, were carried out in methyl ethyl ketone in the presence of benzoyl peroxide as initiator at 50-80°C. Constants of copolymerization, complex formation, and some kinetic parameters for the monomer systems studied were determined by the methods of Hanna-Ashbaugh, Kelen-Tudos, and Seiner-Litt, as well as by dilatometry, respectively. The results show that terpolymerizations were carried out through primary complex mechanisms at near-binary copolymerization of GMA (or MMA) with the St...MA complex. The terpolymers synthesized which comprised free anhydride and epoxide reactive groups easily underwent crosslinking by thermotreatment and by UV irradiation, which was confirmed by DTA, TMA, and FTIR analyses.

Plasma surface modification of polyethylene with organosilicon and organotin monomers

Abstract Plasmochemical modification of a polyethylene (PE) film surface by several selected silicon and tin containing monomers, such as vinyltriethoxysilane (VTES), hexamethyldisiloxane (HMDS), 3-aminopropyltriethoxysilane (APTS), tetraethylstannane (TES) and hexabutyldistannoxane (HBDS) were all examined. The structure and properties of plasma polymers obtained and plasma modified PE film surfaces were studied by FTIR, photoacoustic FTIR spectroscopies and by using surface energy and swelling measurements. It is shown that the structure of plasma polymers formed either on the inorganic non-active or on the organic active (PE films) surfaces do not differ much from each other. In the structure of the organosilicon surface plasma polymers, mainly polysiloxane type fragments emerge; while for the organotin analogs primarily carboxylate fragments predominate. The plasma of organosilicon and organotin compounds were used to modify PE film surfaces to produce thin hydrophobic, biologically active and inactive surfaces. The results of surface energy studies as followed by the interaction with methylene iodide (non-polar) and ethylene glycol (polar components), and degree of swelling studies for both unmodified as well as plasma modified PE films, in xylene showed decrease in the latter and an increase of hydrophobic components as expected.

Effect of inorganic salts on the main parameters of the dilute aqueous poly(vinylpyrrolidone) solutions

Abstract The effect of inorganic salts (cosolute) on the main parameters of dilute aqueous poly(vinylpyrrolidone) (PVP) solutions, such as cloud points, phase diagram, θ temperature and viscosity was studied experimentally using various concentrations of salts and said polymer at varying temperatures. It is shown that, thermodynamic incompatibility of aqueous PVP-salts solutions strongly depends on the character of effect of salts (water-structure breakers or water-structure makers). Inclusion of salts into aqueous PVP solution leads to decreasing of the θ temperature and intrinsic viscosity which is caused by effect of the cosolute ions in enhancing the segment—segment interactions.

Complex-radical copolymerization of 2,4,4-trimethylpentene-1 with maleic anhydride

Abstract The mechanism of radical copolymerization of 2,4,4-trimethylpentene-1 (TMP) as donor monomer with maleic anhydride (MA) as acceptor monomer in the presence of benzoyl peroxide is discussed. The constant of charge transfer complex ( K c ) and copolymerization parameters ( r 1 , r 2 , r 1c , r 1c1 , r 1c2 , Q 1 and e 1 ) have been determined; their values are as follows:xa0 K c =0.27±0.1 L/mol and 0.16±0.07 L/mol at 35°C in CH 3 COCH 3 -d 6 for TMP–TMA and n -octene–MA (model system) complexes; r 1 =0.12±0.005, r 2 =0.38±0.02, r 1c =0.0068, r 1c1 =0.127 and r 1c2 =0.0072; Q 1 =0.0012 and e 1 =0.49. Some kinetic parameters of the reaction and quantitative contributions of TMP–MA complex to reactivity ratios of the monomers have been studied and their contribution to chain growth are estimated as: k 12 / k 21 =3.51, k 1c / k 12 =0.98 and k 2c / k 21 =1.03. The copolymerization is found to proceed predominantly by the “mixed” mechanism with equal participation of complex-bound and free monomers in propagation. A solvent effect in radical copolymerization of TMP with MA is observed. The higher rate of copolymerization in the TMP–MA–dimethylformamide system is explained by the effect of the MA–solvent complex increasing the acceptor properties of the MA molecule.

Complex-radical alternating copolymerization of trans-stilbene with N-substituted maleimides

Radical copolymerization of donor-acceptor monomers, i.e. transstilbene (Stb) with N-maleimide (MI), N-ethylmaleimide (EtMI) and N-phenylmaleimide (PhMI), are studied. Constants of charge-transfer complex formation (K c ) and copolymerization (r 1 and r 2 ) are determined by HannaAshbaugh ( 1 H nuclear magnetic resonance) and Kelen-Tudos methods, respectively. The results obtained were analysed by use of the complex copolymerization model of Seiner-Litt. It is found that the tendency for complex formation and the tendency for alternation of monomers depend on the nature of the N-substituent in the maleimide molecule. K c is found to increase in the order EtMI EtMI > PhMI. It is shown by thermogravimetric analysis, differential thermal analysis and differential scanning calorimetry that the alternating copolymers synthesized have high thermostabilities. The copolymers synthesized show increased thermal stabilities, as well as glass transition temperatures, with the change of imide N-substituent. Stb-MI, Stb-EtMI and Stb-PhMI copolymers decompose through a one-step reaction at 456, 460 and 468°C, respectively.

Preparation and properties of invertase immobilized on a poly(maleic anhydride-hexen-1) membrane.

Poly(maleic anhydride-alt-hexen-1)(poly(MA-alt-H-1)) has been synthesized by radical polymerization and characterized by DSC, FT-IR, acid number determination, viscometric and NMR methods. Data showed that the co-polymer is an alternating co-polymer whose composition does not depend on the monomer feed composition. Invertase was immobilized onto a poly(MA-alt-H-1) membrane via glutaraldehyde and bovine serum albumin. The K m value of poly(MA-alt-H-1)-invertase was approximately 4.4-fold higher than the free enzyme, indicating decreased affinity by the invertase for its substrate (sucrose), whereas V max was lower for the immobilized invertase. Immobilization improved the pH stability of the enzyme, as well as its temperature stability. Immobilized samples obtained were stable and could be used many times over a period of 2 months without considerable activity loss.

Effects of complex formation and cyclization in radical copolymerization of allyl(metha)acrylates with maleic anhydride

Radical copolymerization of allyl acrylate (AA) and allyl methacrylate (AMA) as bifunctional monomers of donor (allyl)–acceptor (acryl) type with maleic anhydride (MA) as an acceptor monomer were carried out in metrhyl ethyl ketone (MEK) at 50–70°C in the presence of 2,2′-azoisobutyronitrile (AIBN) as initiator. Constants of complex formation (Kc), cyclization (kcl), and copolymerization (r1, r2, r1c, r1c1, and r1c2) as well as energies of activation for cyclization (Eac) and copolymerization reactions (Ea), and orders for the monomer (m) and initiator (n) concentrations were determined. The following values were found, for AA and AMA, respectively: Kc = 0.038 and 0.11 L/mol in deutered acetone at 35 ± 0.1°C, kcl = 6.45 and 6.53, r1 = 0.083 ± 0.005 and 0.028 ± 0.002, r2 = 0.027 ± 0.002 and 0.063 ± 0.003 (by the Kelen–Tudos method), r1c = 0.04 and 0.025, r1c1 = 0.128 and 0.176, r1c2 = 0.127 and 0.177 (by the Seiner–Litt equation), Eac = 28.9 and 28.7 kJ/mol, Ea = 67.0 and 87.9 kJ/mol, m = 1.53 and 1.45, and n = 0.50 and 0.52. The presence of cyclic, unsaturated, and anhydride fragments in the macromolecules was confirmed with FTIR data and chemical (iodometrical and potentiometric titrations) analysis. It was established that complex formation in the monomer systems studied is the main factor for alternating cyclocopolymerization leading to formation of copolymers containing lactone and linear-unsaturated fragments in the macromolecular chain.

Alternating cyclopolymerization of allyl trans-cinnamate and maleic anhydride

Abstract Some features of the radical copolymerization of allyl cinnamate bifunctional monomers, containing donor (allyl)-acceptor (β-phenylacryl) double bonds in the molecule, with maleic anhydride have been revealed. The kinetic parameters of the reactions, including their complex-formation, cyclization and copolymerization constants, as well as the ratios of chain growth rates for the participation of monomeric charge-transfer complexes and free monomers, are all determined. It has been established that an alternative cyclocopolymerization reaction is realized, which is carried out via a complex mechanism with the formation of macromolecules with unsaturated cyclo-linear structures. The synthesized copolymers show high sensitivity to ultraviolet irradiation, electron beams and X-rays, but their negative resists differed, with high lithographic parameters and plasma stability.

Synthesis and photochemical reactions of functional organotin macromolecules

Abstract The alternating copolymers of allyl chloroacetate (ACA) and allyl propionate (AP) with maleic anhydride (MA) and their organotin derivatives were synthesized by radical copolymerization in the presence of benzoyl peroxide as initiator in benzene at 70°C and by the polymer-analogous reaction of anhydride-containing copolymers prepared with hexa-n-butyldistannoxane, respectively, and all were characterized. The alternating copolymers of monoallyl maleate (MAM) and tri-n-butylstannylallyl maleate (TBSAM) with styrene (St) and MA were also synthesized by radical copolymerization in methylethylketone in the presence of benzoyl peroxide at 60°C. Photochemical reactions and structure-property correlations in the synthesized copolymers containing Sn, Oue5fbC, Cl and Cue5fbC (side-chain allyl or vinylene groups) were studied by using u.v.-irradiation with monochromatic light at 405 nm, Fourier transform infrared (FTi.r.) spectroscopy, differential thermal analysis (d.t.a.) and thermogravimetric analysis (t.g.a.). It is shown that unlike anhydride-containing copolymers which decompose easily upon u.v.-irradiation, the organotin derivatives cross-link under similar conditions. It is explained that the relatively low values of the quantum efficiency, ϕcrl = 0.035 – 0.11 mol Einstein−1, of the photochemical conversion and the high photosensitivity, S = 6.8–21.6 cm2J−1, for the organotin copolymers is provided by coordination-bound organotin fragments with sensitive CH2ue5f8Sn groups which transfer readily to the intermolecular carboxylate form under the conditions of photooxidation.