Methyl Methacrylate-methacrylic Acid Copolymers Research Articles

Preparation and thermal degradation of methyl methacrylate-methacrylic acid copolymers

Copolymers of methyl methacrylate with methacrylic acid, with the mole fraction of methacrylic acid units from 0.21 to 0.73, were prepared by radical copolymerization in the bulk. The influence of the composition of the copolymers on the features of their thermal degradation was examined by combined thermal analysis involving differential scanning calorimetry and thermogravimetry.

Influence of the silver ions on the physicochemical properties of methyl methacrylate-methacrylic acid copolymer films

The effect of silver ions on the physicochemical properties of methyl methacrylate-methacrylic acid copolymer films, namely, film-forming properties and resistance to fluorine-containing plasma, acid etchers, and temperature, was studied by lithography, derivatography, atomic-force microscopy, and optical spectroscopy. The activation energies were calculated for thermal transformations in the copolymer with and without silver ion additions, when heated in air to 300°C.

Spectral-luminescent and generation properties of rhodamine dyes in thin polymer films under optical excitation

A study was made of the absorption, fluorescence, and emission spectra of organic dyes Rhodamine 6Zh and Rhodamine C in thin (0.6–1.0 µm) layers based on methyl methacrylate-methacrylic acid copolymers formed by centrifugation on optically transparent glasses. The influence of a terbium salt on the properties of laser dyes in acrylic films was elucidated.

Thermal analysis and NMR studies of methyl methacrylate (MMA)-methacrylic acid copolymers synthesized by an unusual polymerization of MMA

Methyl methacrylate-methacrylic acid (MMA-MAA) copolymers were pre- pared from the polymerization reaction of the methyl methacrylate (MMA) monomer with concentrated nitric acid (65% HNO3) at different reaction times in the absence of other reagents in the reaction mixture. The hydrolysis degrees of the MMA-MAA (sodium salts) copolymers estimated by thermogravimetry (TG) corroborated the data obtained by chemical titration. By calorimetry (DSC), a relationship between the glass transition temperature (Tg) and the hydrolysis degree was obtained. The results pre- sented a deviation from linear behavior and it was related to the strength of the interactions involved in the copolymer chains. The equation that relates the glass transition temperature to the interaction parameter, x, for miscible binary polymer blends was applied for the MMA-MAA copolymers and demonstrated the composition dependence of x. The molecular mobility was determined by nuclear magnetic reso- nance (NMR) in the solid state and through the proton spin-lattice relaxation time in the rotating frame. The NMR data were in a good agreement with the results obtained by calorimetry. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 495-507, 2000

Pervaporation characteristics of methyl methacrylate-methacrylic acid copolymer membranes ionically crosslinked with metal ions for a benzene/cyclohexane mixture

Methyl methacrylate–methacrylic acid copolymer (MMA–MAA) membranes ionically crosslinked with Fe3+ and Co2+ ions (MMA–MAA–Fe3+ and –Co2+) were prepared, and characteristics of permeation and separation for a benzene/cyclohexane mixture of 50 wt % benzene through these membranes in pervaporation (PV) were studied. Although the introduction of the metal ions to the MMA–MAA membrane enhanced both benzene permselectivity and permeability for a benzene/cyclohexane mixture, the PV characteristics between the MMA–MAA–Fe3+ and –Co2+ membranes were significantly different. The difference in the PV characteristics between these membranes was strongly governed by the difference of these membrane structures based on the glass transition temperature, contact angle to methylene iodide, degree of swelling, and mixture composition absorbed in the membrane, and so on. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 233–241, 1999

Characterization of methacrylic polymers by calorimetry and infrared analyses

Methyl methacrylate-methacrylic acid (MMA-MAA) copolymers, prepared by the action of concentrated nitric acid (65% HNO 3 ) on methyl methacrylate in absence of other reagents, were characterized using calorimetry (DSC) and infrared (FTIR) analyses. DSC curves of ester/acid copolymers suggested the anhydride formation at ∼200°C, which was corroborated by thermogravimetry (TG). This structure was assigned by FTIR spectra. The results obtained by DSC data are in good agreement with the hydrolysis degree of the MMA-MAA copolymers obtained from chemical titration. The molecular weight of the copolymers were estimated by viscometry.

Fluorescence study of the interaction between metal ions and methyl methacrylate-methacrylic acid copolymers in aqueous solutions: thallium(I), calcium(II), and terbium(III)

The binding of the cations thallium(I), calcium(II) and terbium(III) to methyl methacrylate– methacrylic acid copolymers with different fractions of acid groups (x) has been studied in aqueous solution at various pH values using the fluorescence of covalently bonded 9-vinyl anthracene as a probe. In all cases, the extent of binding increases as a function of the charge of the polymer with either increasing fraction of carboxylic acids or of pH. However, differences are observed in the behavior of the three cations. With Tl(I), quenching of the anthracene group fluorescence is observed, indicating that the thallium(I) approaches the probe and suggesting that the alkylanthracene is probably in a relatively polar region. Binding constants have been determined from anthracene quenching data and from studies with the fluo-rescent-probe sodium pyrenetetra-sulfonate. Good agreement is obtained between the two methods, and values for the binding constants increase from 250 to 950 M-1 as x increases from 0.39 to 1. It is suggested that the cation is held in the polyelectrolyte domain, partly by Debye–Huckel effects and partly by more specific interactions. Stronger binding is found with calcium(II) and terbium(III), and in this case increases in fluorescence intensity are observed on complexation due to the anthracene group being in a more hydrophobic region, probably as a result of conformational changes in the polymer chain. In the former case the stoichiometry of the interaction was determined from the fluorescence data to involve two carboxylate groups bound per calcium. Association constants were found using murexide as an indicator of free calcium to vary from 8400 to 37 000 M-1 as x increases from 0.39 to 1. It is suggested that in this case specific calcium(II)–carboxylate interactions contribute to the binding. With terbium(III), a greater increase in the probe fluorescence intensity was observed than with calcium, and it is suggested that the interaction with the polymer is even stronger, leading to a more pronounced conformational change in the polymer. It is proposed that the terbium(III) interacts with six carboxylic groups on the polymer chain, with three being coordinated and three attracted by electrostatic interactions.

Studies on permeation through polymer latex films, III. Modification using soluble polymeric additives

AbstractThe influence of two distinct types of water leachable polymeric additives upon the transport properties across polymer latex films is considered. Hydroxypropyl methylcellulose, added as an aqueous solution, and a methyl methacrylate–methacrylic acid copolymer, added as latex particles, are both shown to be more effective than lower molecular weight rapidly water soluble additives, typified by sucrose, in enhancing solute transport and creating pathways for convective diffusion.

The compatibilization of methyl methacrylate-methacrylic acid copolymer and polystyrene through the functionalization of polystyrene

The compatibility of ionomer/polymeric acid blends has been studied for polymer pairs consisting of sodium salts of sulfonated polystyrene and methyl methacrylate-methacrylic acid copolymer using dilute solution viscometry. The intrinsic viscosities of the blends, prepared in three different weight fractions (25, 50 and 75%) using the solution-blending technique, were measured in two solvents with different polarities: dioxane ( ϵ = 2.24) and tetrahydrofuran ( ϵ = 7.26). The degree of compatibility of the blends was characterized using the Δb parameter. Results show that the percentage sulfonation, temperature and polarity of the solvent all affect the miscibility.

Composition distribution separation of methyl methacrylate-methacrylic acid copolymers by normal-phase gradient elution high-performance liquid chromatography

The characterization of copolymers requires the determination of chemical composition distribution in addition to molecular mass ( M) distribution. Techniques commonly applied to copolymer analysis provide either average bulk composition or a convolution of M and composition distributions. The application of gradient elution adsorption chromatography, under appropriate conditions, allows the separation of copolymers based solely upon their chemical composition in a M-independent mode. Separation independent of M requires the elimination of size-exclusion effects with the porous adsorbent and the minimization of precipitation contributions. For separation over a wide copolymer composition range, the relative contributions of adsorption and precipitation retention mechanisms change with solvent composition. Under gradient elution conditions where adsorption retention dominates, composition fractionation can be combined with subsequent size-exclusion chromatography to provide a complete composition/ M map of the copolymer.

Effect of ion association on the properties of ionomers obtained from methyl methacrylate-methacrylic acid copolymer

The solution behaviour of Na, Ba, Zn and Al ionomers of methyl methacrylate-methacrylic acid copolymer (P(MMA-MAA)) with different ion contents has been studied by viscosity and dipole moment measurements. Two solvents with different character are chosen for viscosity measurements: dioxane ( ε = 2.22) and acetone ( ε = 20.7). The expected polyelectrolyte behaviour of the ionomers in acetone is reflected by the viscometric measurements. Mean squared dipole moment 〈 μ 2〉 values are calculated over a temperature range of 20–100°C in dioxane. Effects of neutralization, cation size and cation charge are discussed for each ionomer.

Intramolecular anhydrization of methyl methacrylate-methacrylic acid copolymers in sulpholane

An investigation has been made of the laws governing the intramolecular anhydrization of an MMA-methacrylic acid copolymer under the action of acetic anhydride in a sulpholane medium in the temperature range 160–185°C. IR spectroscopy and 13C nuclear magnetic resonance have been used to study the composition and structure of the anhydride copolymer and it has been shown that cyclization of the initial copolymer leads to the formation of six-membered rings of the glutaric anhydride type in the macromolecules.

Assignments for the 1H-NMR of alkoxy groups in syndiotactic methacrylate copolymers—I : Methyl methacrylate-methacrylic acid copolymers and methyl methacrylate-diphenylmethyl methacrylate copolymers

Unusual assignments have been observed for the 1H-NMR of alkoxy groups in syndiotactic methyl methacrylate-methacrylic acid (MMA-MAA) copolymers and methyl methacrylate-diphenylmethyl methacrylate (MMA-DPMMA) copolymers. Thereby, the alkoxy groups OCH 3 and OCH show a degenerate pentad assignment, in as much as the two monomer units nearest to the central monomer unit exert no differentiating influence on chemical shift, in contrast to the two next-to-nearest monomer units. By the use of copolymers possessing a tendency toward alternation with respect to compositional statistics, it is possible to distinguish between a degenerate pentad and a normal triad assignment. The reason for the degenerate pentad assignment is seen in specific conformations of the pentads, leading to the elimination of the differentiating influence on chemical shift for the two monomer units nearest to the central unit.

Association between acidic and basic copolymers by low angle laser light scattering photometry

Measurements of both apparent molecular weight and second virial coefficient of solutions of styrene-4-vinylpyridine copolymer in ethyl benzoate containing varying concentrations of methyl methacrylate-methacrylic acid copolymer isorefractive with ethyl benzoate were carried out by low angle laser light scattering. The apparent molecular weight depended very little on the acidic copolymer concentration. The second virial coefficient first decreased rapidly, then increased and finally tends to level off as the acidic copolymer concentration was raised. Great association is observed when the visible polymer is in excess.

A novel approach to o-nitrobenzyl photochemistry for resists

We have developed a two-component (resin-solution inhibitor) resist system having good photosensitivity in the 230–300 nm range. The resin is an optically transparent methyl methacrylate-methacrylic acid copolymer that is soluble in aqueous alkali. The second component is one of a family of o-nitrobenzyl carboxylates that are initially insoluble in the alkaline developer but are cleaved to soluble components upon irradiation. A number of o-nitrobenzyl alcohol esters have been prepared and examined for use in this two-component system. They have proven useful in the development of sensitive high-resolution short-wavelength photoresists which are described.

Effect of molecular weight on the viscosity of moderately concentrated solutions of polymethylmethacrylate and of methyl methacrylate-methacrylic acid copolymers

The viscosities of solutions in dimethylformamide of polymethylmethacrylate and of methyl methacrylate-methacrylic acid copolymers with M>10 5 have been measured over a wide range of temperatures and shear stresses. The properties of solutions of methyl methacrylate-methacrylic acid copolymers prepared by radical copolymerization and by hydrolysis have been compared. It is shown that the concentration of methyl methacrylate links in the copolymer has almost no effect on the solutions' viscosity. The ways in which the viscosity and activation parameters for the viscous flow of the systems depend on molecular weight have been studied. It has been found that the value of α in the relationship ν ∼ M α is greater than the figure of 3·4 associated with melts and solutions of flexible-chain non-polar polymers.

1H-NMR of the esterification of syndiotactic poly(methacrylic acid) with carbodiimides—I. Esterification with methanol

The esterification of syndiotactic poly(methacrylic acid) with methanol in the presence of dicyclohexylcarbodiimide as a condensing agent has been studied, evaluating triads by 1H-NMR. The reaction proceeds via a cyclic anhydride as an intermediate, which with methanol then forms the ester. This mechanism leads to a limiting conversion and to a tendency toward alternation for the sequencing of esterified and unesterified monomer units along the chain. The statistics of the methyl methacrylate-methacrylic acid copolymers can be approximated by conditional probabilities of first order.

NMR Study of the Chain Microstructure of P(MMA-co-MAA)

The usefulness of proton and carbon-13 NMR spectroscopy in characterizing the chain microstructure (i.e., sequence distribution and tacticity) of methyl methacrylate-methacrylic acid (MMA-MAA) copolymers has been investigated. Because the comonomers have such similar structures, assessment of chain tacticity and sequence distribution required computer simulation of spectra to circumvent the problems of resonance overlap. The computer analysis used 1H and 13C chemical shift data on homopolymers and sterically-defined copolymers, Bernoullian and Markovian statistics for the respective tactic and sequence distributions, and a Lorentzian lineshape program to generate a theoretical spectrum. The generating parameters that produced simulation of both the 1H and 13C spectra provided the basis for describing the triad microstructure of the copolymers. This method of characterizing the microstructure was applied to copolymers of similar composition but different preparative histories. The results indicated that free-radical polymerization in toluene yielded a heterogeneous copolymer system while free-radical polymerization in tetrahydrofuran (THF) and emulsion polymerization yielded relatively homogeneous systems.

The vapour sorption kinetics for dimethylformamide by methyl methacrylate-methacrylic acid copolymers

The kinetics of vapour sorption for DMF by films of methyl methacrylate-methacrylic acid copolymers (up to 21 mole% of the second component) have been found to give a peak on the kinetic curves which becomes rapidly smaller as the acid content increases. One can explain this effect on the basis of porometry as due to the mechanism of sorption by pores (channels) in combination with the relaxation rearrangement of the supermolecular organization of the copolymers.

New photosensitive polymers derived from glycidyl cinnamate

New photosensitive polymers were derived from glycidyl cinnamate with which methylmethacrylate-methacrylic acid copolymer (I) or an acid anhydride (II) was allowed to react. The product from (I) showed better photosensitivity than that from (II) from the point of view of insolubility in tetrahydrofuran. Infra-red spectroscopy can be used to follow changes during irradiation.