Terpolymer Of Methyl Methacrylate Research Articles

Design of New Polyacrylate Microcapsules to Modify the Water-Soluble Active Substances Release.

Despite the poor photochemical stability of capsules walls, polyacrylate is one of the most successful polymers for microencapsulation. To improve polyacrylate performance, the combined use of different acrylate-based polymers could be exploited. Herein butyl methacrylate (BUMA)-based lattices were obtained via free radical polymerization in water by adding (i) methacrylic acid (MA)/methyl methacrylate (MMA) and (ii) methacrylamide (MAC) respectively, as an aqueous phase in Pickering emulsions, thanks to both the excellent polymer shells’ stability and the high encapsulation efficiency. A series of BUMA_MA_MMA terpolymers with complex macromolecular structures and BUMA_MAC linear copolymers were synthesized and used as dispersing media of an active material. Rate and yield of encapsulation, active substance adsorption onto the polymer wall, capsule morphology, shelf-life and controlled release were investigated. The effectiveness of the prepared BUMA-based microcapsules was demonstrated: BUMA-based terpolymers together with the modified ones (BUMA_MAC) led to slow (within ca. 60 h) and fast (in around 10 h) releasing microcapsules, respectively.

Towards Novel Fluorinated Methacrylic Coatings for Cultural Heritage: A Combined Polymers and Surfaces Chemistry Study.

In this work, new co- and ter-polymers of methyl methacrylate (MMA), ethyl methacrylate (EMA), and N-butyl methacrylate (nBuMA), containing just 1% mol × mol−1 of a fluorinated co-monomer, 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluoro-octyl methacrylate (POMA), were synthesized. After an UV accelerated aging test, the photo-chemical stability of the polymers prepared was determined by 1H NMR and FT-IR spectroscopy, size exclusion chromatography, differential scanning calorimetry and wettability measurements. The polymers were applied to Botticino tiles to achieve better performances in terms of water repellency and consequently deterioration resistance. One-year prolonged exposure to a real environment was conducted and the properties of the coated materials and their performances were studied using different surface techniques such as water contact angle (WCA) and colorimetric measurements (CIELaB), capillary absorption, permeability (RVP) tests and soluble salts determination. The effectiveness of the fluorinated methacrylic coatings was clearly demonstrated; among all the resins, the co-polymer MMA_POMA seems to be the most performing one. Furthermore, both the UV photo-chemical resistance and the easiness of removal was successfully studied.

Study of Processing Parameters of Preparation of Wood-Polymer Composite by Synthesis of Terpolymer in Wood Porous Structure

Inspired from the natural porous structure of wood, a novel wood-polymer composite combining both advantages of wood with high strength-to-weight ratio as a natural renewable resource and polymer as a reinforcer was manufactured by synthesis of terpolymer of methyl methacrylate (MMA), Styrene (St) and Vinyl Acetate (VAc) inside wood. The three kinds of monomers with a few of 2,2'- azobisisobutyronitrile (AIBN) as an initiator, as well as some additives were first impregnated into wood porous structure under a pressure condition, and then initiated for terpolymerization through a catalyst-thermal treatment. The impregnating conditions containing pressure value and pressure time, and polymerizing crafts including heating temperature and heating time, as well as additive content were confirmed according to rate of monomer loading and rate of polymer loading inside wood. Results indicate that among these influencing factors, pressure and temperature were the significant influencing factors; and the rate of monomer loading and rate of polymer loading linearly positive correlated to them, respectively. SEM observation shows that the terpolymer fully filled in wood porous structure under the optimum manufacturing craft.

Photophysical characterization of pyrromethene 597 laser dye in silicon-containing organic matrices

Samples of dipyrromethene-BF2 dye PM597 incorporated in copolymers of 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) with methyl methacrylate (MMA) and 2-hydroxyethylmethacrylate (HEMA), and in terpolymers of MMA, HEMA and TMSPMA are characterized. The absorption cross-section spectra, stimulated emission cross-section spectra, and the excited-state absorption cross-section at 527 nm are determined. The fluorescence quantum distributions and fluorescence lifetimes are measured. The photo-degradation is studied under cw laser excitation conditions and quantum yields of photo-degradation are extracted. PM597 solid state samples are compared with PM597 in liquid ethyl acetate solution. The fluorescence quantum yield of PM597 is higher in doped samples (around 70%) compared to PM597 in ethyl acetate (43%). The excited-state absorption cross-section was found to be negligibly small. The photo-stability is considerably larger in the polymeric samples compared to the liquid solutions.

THERMOANALYSIS AND MECHANICAL PROPERTIES OF EMULSION COPOLYMER POLY(MMA-PMI-ST)

Terpolymers of methyl methacrylate (MMA), N-phenylmaleimide (PMI) and styrene (St) were synthesized by emulsion copolymerization. The glass transition temperatures (Tg) and the thermostability of copolymers were determined by differential scanning calorimetry (DSC) and programmed thermogravimetric analysis (TGA), respectively. The terpolymers show a considerable increase in decomposition temperature, activation energy of decomposition and Tg with increasing content of PMI. Furthermore, the Vicat softening points of the terpolymers rise with PMI content. The mechanical properties (tensile strength and impact strength) of the terpolymers decrease with increasing PMI content and increase insignificantly with increasing St content.

Stability of radiopaque iodine-containing biomaterials

Stability tests have been performed on two typical iodine-containing radiopaque poly(methacrylate) copolymers. Material A is a terpolymer of methylmethacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA) and 2-[4-iodobenzoyl]-oxo-ethylmethacrylate (4-IEMA); material B is a copolymer of MMA and 4-IEMA. Cylindrical specimens of material A were implanted subcutaneously and intraperitoneally in Wistar rats. The implants were retrieved after 2 years. Histology showed that the material was well-tolerated. Detailed analysis of the surface of the implants by electron spectroscopy for chemical analysis (ESCA) revealed that the material remained stable. No differences could be detected between the ESCA spectra of the explants, and those of the control specimens, which were from the same synthetic batch and which were stored in dry form during the entire experimental period. Material B was also stable upon irradiation with X-rays in vitro, even at high doses, compared to the clinical situation. Exposure of material B to γ-radiation, however, was found to lead to structural degradation. This was evident from clear yellowing, and also from the ESCA spectra. The spectra revealed that material B deteriorates during γ-irradiation through rupture of C–C and/or C–O chemical bonds, not via C–I bond disruption. It can be concluded that iodine is tightly bound to these radiopaque biomaterials. This is important with regard to potential applications of these materials as implant biomaterials.

Thermoanalysis and rheological behavior of emulsion copolymers of methyl methacrylate, N-phenylmaleimide and styrene

Terpolymers of methyl methacrylate (MMA), N-phenylmaleimide (PMI) and styrene (St) were synthesized by emulsion copolymerization. The thermal stabilities of terpolymers were studied by a programmed thermogravimetric analysis (TGA) technique. Terpolymers show a considerable increase in decomposition temperature with increasing feed content of PMI and St. The glass transition temperatures (T g ) of copolymers were measured by differential scanning calorimetry (DSC) and torsional braid analysis (TBA). The terpolymer's T g increases markedly with the increasing PMI feed content, while it decreases with increasing St feed content. The rheological behaviors of copolymers were also studied. The terpolymer's apparent viscosity in melt decreases with increasing feed contents of PMI and St. The terpolymer's flow index n increases with the increasing feed content of PMI. The results also show that the difference value between T gDSC and T gTBA , ΔT g increases with an increase in the terpolymer's flow index. M w and M n of copolymers were also determined by gel permeation chromatography (GPC).

Combinatorial approach for the synthesis of terpolymers and their novel application as very-high-contrast resists for x-ray nanolithography

Novel resist systems for x-ray lithography, specifically optimized in terms of contrast enhancement are described. Based on terpolymers of methyl methacrylate (MMA)-tert-butylacrylate-polyhedral oligosilsesquioxanes (POSS) synthesized by solution polymerization, these systems were optimized by a combinatorial approach. It is shown that the mass ratio of MMA/POSS=85.7/14.3 leads to maximum contrast (23.5) without sacrificing the sensitivity (1350 mJ/cm2) which remains comparable to that of standard PMMA. Such major contrast enhancement shows that the above organic/inorganic nanocomposites are promising candidates for sub-100 nm lithography.

Compatibilization of PBT/ABS blends by methyl methacrylate-glycidyl methacrylate-ethyl acrylate terpolymers

Poly (butylene terephthalate), PBT, can be impact modified by blending with appropriate ABS materials within a limited range of processing conditions. The morphology of these uncompatibilized blends is unstable; the dispersed phase coarsens when the melt is subjected to low shear conditions, e.g. during certain moulding conditions, which has a deleterious effect on the final blend properties. Terpolymers of methyl methacrylate, glycidyl methacrylate (GMA), and ethyl acrylate have been synthesized and shown to be effective reactive compatibilizers for blends of PBT with styrene-acrylonitrile copolymers (SAN) or ABS materials as revealed by improvements in SAN or ABS dispersion and morphological stability. Evidence for reaction between the carboxyl endgroups of PBT and the epoxide groups of GMA during melt processing to form a graft copolymer is presented. The effect of terpolymer composition and content on morphology generation and stabilization of PBT-SAN blends has been examined in depth. Moderate amounts of GMA in the terpolymer (>5%) and small amounts of compatibilizer in the blend (<5%) were found to significantly improve SAN dispersion. Blends of PBT and SAN containing the compatibilizer did not show any coarsening of the dispersed phase particle size due to coalesence under certian conditions of low shear. A preliminary investigation into the effect of this compatibilizer on PBT-ABS morphology and impact properties revealed greatly improved rubber dispersion and low temperature toughness.

Synthesis of Silicon-Containing Photoresists for ArF Excimer Laser Lithography

Two new positive-type photoresists which are terpolymers of methyl methacrylate (MMA), 1,3-bis(trimethylsilyl)isopropyl methacrylate (BPMA) and either methacrylic acid (MAA) or maleic anhydride (MA) have been synthesized for ArF excimer laser lithography. Terpolymers have a silicon containing acid labile protecting group which can be deprotected by photo acid generator (PAG). Terpolymers have a good thermal stability up to 140°C and the glass transition temperature (Tg) of poly(MMAx-BPMAy-MAz) was 119°C. The minimum feature resolution with 0.17 µm L/S pattern was achieved with poly(MMA5.9-BPMA2.1-MAA2.0) by using an ArF exposure system with 17 mJ/cm2 energy dose.

Dilute solution viscosimetry of carboxylated acrylic lactices

Measures the intrinsic viscosities, in acetone and tetrahydrofurane (THF) at different temperatures, of a terpolymer of methyl methacrylate, ethyl acrylate and methacrylic acid, prepared by semicontinuous emulsion polymerization (latex). Analyses data with the aid of the equations of Huggins, Kraemer, Martin, Schulz‐Blaschke and an equation recently suggested by Rao. Considers relationships between different parameters. By comparing uncleaned samples with samples purified by single precipitation or by dissolution and precipitation from THF, observes the effects of low‐molecular weight and water‐soluble on the intrinsic viscosities. Discusses solvent powers and effects of degree of purification and temperature on viscosity. Discusses polymer‐solvents interactions in terms of the acceptor/donor properties of the solvents. Concludes that purification of functionalized latices can lead to modifications of the original systems, through the elimination of different polymer chains.

Acid-catalyzed single-layer resists for ArF lithography

A positive-tone single-layer resist for use with 193-nm radiation has been developed. The system contains a terpolymer of methyl methacrylate, methacrylic acid, and t -butyl methacrylate, along with a photoacid generator. The chemically amplified deprotection of the t -butyl methacrylate into methacrylic acid increases the polarity of the resist and allows selective dissolution in metal-ion-free aqueous-base solutions. The resist sensitivity is less than 10 mJ/cm 2 , and its inherent resolution is better than 0.1 μm. These acrylate-based systems have the potential to be both lower in cost and have better environmental stability than the deep ultraviolet chemically amplified resists that use phenolic resins.

Synthesis and evaluation of methyl methacrylate copolymers and terpolymers as electron beam resists. II. Methyl methacrylate copolymers and terpolymers containing aromatic rings

AbstractTerpolymers of methyl methacrylate and methacrylic acid with vinyl monomers, styrene, 4‐(α, α‐dimethylbenzyl) phenyl methacrylate and 2‐naphthyl methacrylate, were synthesized by radical terpolymerization. The molecular weights of the polymers obtained cover the range of 40,000 to 120,000. It was established that the molecular weight characteristics of the terpolymers are influenced by the content of methacrylic acid in the initial polymerization mixtures, by the chemical nature of the aromatic vinyl comonomer, and by the nature of the solvent and the concentration of the initiator. The sensitivity of the polymers towards radiation was estimated by the G‐values obtained after the products were subjected to γ‐ray treatment. The influence of the chemical composition of the terpolymers on their sensitivity is discussed in detail. © John Wiley &amp; Sons, Inc.

Chain entanglement in homopolymers, copolymers and terpolymers of methyl methacrylate, styrene and N-phenylmaleimide

Chain entanglement in poly (methyl methacrylate), polystyrene, poly poly( N-phenylmaleimide), poly(methyl methacrylate- stat-styrene), poly(methyl methacrylate- stat- N-phenylmaleimide) and poly(methyl methacrylate- state-styrene- stat- N-phenylmaleimide) is studied in the melt by dynamic viscoelastic spectroscopy. It is shown that the plateau modulus is equal to the storage modulus at the minimum of loss tangent. The plateau modulus and the entanglement molecular weight are found to obey the geometric mean relationship with respect to composition, i.e. log G 0 N = ∑ v j log G 0 N j and log M e = ∑ v j log M e j , where G 0 N is the plateau modulus, M e the molecular weight between entanglement points, v j the volume fraction of comonomer j, G 0 N j the plateau modulus for the homopolymer of j and M e j the entanglement molecular weight for the homopolymer of j. The G 0 N and M e of homopolymers and copolymers may also be predicted by group additivity method.