Poly Alkyl Acrylate Research Articles

Performance of Polyalkyl Acrylate Additives of Various Compositions in Low-Temperature Dewaxing of Oil Raffinates

The performance of polyalkyl acrylate additives of various compositions in low-temperature dewaxing of 11 oil fractions differing in the viscosity and content of waxes, aromatic hydrocarbons, and resins was studied. The dewaxing was performed in a methyl ethyl ketone–toluene mixed solvent. For polyalkyl acrylate with pendant C16–10 alkyl chains, the raffinates can be subdivided into three groups with respect to an increase in the yield of dewaxed oils (relative to the process without additives): increase by 12–13, 5–8, and 3–4%. In most cases, introduction into such polymer of 5–30% polar groups (amino ester, amino amide, amide, oligoethylene glycol) allowed the oil yield to be additionally increased.

Performance of Polyalkyl Acrylate Additives of Various Compositions in Low-Temperature Dewaxing of Oil Raffinates

Performance of Polyalkyl Acrylate Additives of Various Compositions in Low-Temperature Dewaxing of Oil Raffinates

Dependence of efficiency of polyalkyl acrylate-based pour point depressants on composition of crude oil

Thirteen polyalkyl acrylate-based depressor additives with C16-C26 alkyl groups containing 0–30 mol% of various polar groups (amide, amine, ammonium, N-vinylpyrrolidone, oligo(ethylene glycol)) have been synthesized and tested in 18 crude oil samples of significantly different compositions. It has been shown that the dependences of the depressor effect on the additive concentration pass through maxima. An approach that predicts the degree of decrease in pour point of oil in the presence of polyalkyl acrylate additives depending on the content of paraffin and resin-asphaltene components was proposed for the first time. A polyalkyl acrylate with C16-20 alkyl groups proved to be the most versatile additive. However, polymers with different lengths of alkyl groups or containing polar groups are more effective for some oils.

Development of polymethacrylate thickener for low pour point transmission oil

The influence of the molecular weight and composition of polyalkyl (meth) acrylate thickeners on the properties NS-3 ultralow pour point naphthenic base oil (Nynas, Sweden) was determined. Using standard experimental techniques, it has been shown that copolymers of higher alkyl methacrylates with C12- C15 alkyl groups, containing 5- 15% methyl methacrylate or butyl methacrylate units and having an average molecular weight М n = 18000- 20000, have good thickening properties and high resistance to mechanical destruction (which are not inferior to the indicators of the used foreign additive Viscoplex 0-220). The results made it possible to develop a thickening additive K-64-03 for low pour point transmission oil, which can be used in highly loaded machinery in the winter conditions of the Far North. Additive K-64-03 exhibits the required thickening properties at elevated and negative temperatures, does not worsen the ultra-low pour point of the base oil (below minus 70°C) and has a high resistance to mechanical destruction.

Investigation of the Pour Point Depression Ability of Polyalkyl Acrylate Additives After Sonication

Effect of ultrasonic treatment on the molecular parameters of polymeric additives based on polyalkyl acrylate is investigated. The viscosity, temperature, and energy characteristics of high-wax crude oil and solutions of petroleum wax in decane and aviation fuel TS-1 in the presence of initial and ultrasonified additives are determined. Results obtained indicate that the pour point depression ability of the additives is not reduced after treatment in an ultrasonic field.

Effect of ammonium-containing polyalkyl acrylate on the rheological properties of crude oils with different ratio of resins and waxes

A composite additive for oil pipeline pumping has been tested as a viscosity modifier and crystallization modifier (depressant) in two crude oils and gas condensate of West Siberian deposits with the different content of resins and waxes. The additive represents a toluene solution of a cationic surfactant and an amphiphilic copolymer of alkyl acrylate C16-C20 with a salt of acrylic acid and higher amine. Pour points, rheological characteristics, phase transition temperatures, energies of the destruction of supramolecular structures were determined for investigated oils with different concentrations of the additive. The comparison of the efficiency was made for the composite additive, a commercial depressant and surfactant-free additive.

Study on the molecular behavior of hydrophobically modified poly(acrylic acid) in aqueous solution and its emulsion‐stabilizing capacity

AbstractIn this article, molecular conformation and aggregation behavior of partly hydrophobically modified poly(acrylic acid) (HMPAA) in aqueous solution has been studied by mesoscale simulation approach dissipative particle dynamics for the purpose to find out how the chemical structure and environmental conditions effect its capacity. It has been found that, as a kind of pH‐sensitive polymer, the chemical structure variation of HMPAA carried by adjusting pH and grafting degree influence the taking place of intermolecular and intramolecular associations, which induced the formation of molecular network and help to maintain high bulk phase viscosity of its aqueous solution in larger pH range or under higher salinity comparing with PAA. There exists an optimum grafting degree, above which the increase of the possibility of the intramolecular associations enhance the coiling of the polymer chain and result in destroy of the network. The experimental determination of properties of aqueous solutions of poly(acrylic acid) (U10) and poly alkyl acrylate (U20), such as the bulk phase viscosity and oil/water interface tension, accord well with the molecular simulation conclusion, by which the mechanisms of elevated stability of surfactant‐free O/W emulsion stabilized by the HMPAA comparing with PAA has been discussed. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

SYNTHESIS AND CHARACTERIZATION OF POLYURETHANE ACRYLATES FOR UV CURABLE COATING AGENTS

The single hydroxyl-terminated urethane acrylate oligomers were synthesized from 2-mercaptoethanol (2-MEOH), alkyl (methyl, butyl, and 2-ethylhexyl) acrylate, and 2,2-azobisisobutyronitrile (AIBN, initiator), with dibutyltin dilaurate (DBTDL) as a catalyst. 2-MEOH was used as a functional chain transfer agent. Poly(alkyl urethane) acrylate oligomers were obtained by the reaction of single hydroxyl-terminated polyalkyl acrylates and 2-isocyanatoethyl acrylate. They were characterized by NMR, FT-IR spectroscopy, rheometer, and DSC. Because poly(alkyl urethane) acrylate oligomers have lower Tg and viscosity than hydroxyl-terminated polyalkyl acrylate oligomers (HTPAO) non-containing urethane groups, they can be used for ultraviolet (UV) curable coatings, inks, and adhesives.

Mechanical and thermomechanical characterization of PVC/polyalkylacrylate blends

AbstractThe effect of blending poly(ethyl acrylate) and poly(butyl acrylate) in various proportions with suitably stabilized and plasticized polyvinyl chloride (PVC) was studied with reference to their physical, mechanical, thermal, and morphological properties. The tensile modulus and ultimate tensile strength indicated a rise initially, followed by their steady decrease with increasing concentration of the polyalkyl acrylates. A corresponding behavior of elongation at break and toughness are exhibited. The various polyblends exhibit thermal stability over unmodified PVC, as reflected from their thermomechanical studies, in which the penetration is also inversely related to the respective moduli. The biphasic cocontinuous systems as explicit from the morphological studies support phase mixing at the initial stages, with subsequent phasing‐out tendency, with increasing percentage of polyalkyl acrylate incorporation. The thermomechanical parameters are in conformity to their mechanical parameters, which have been further supported by their morphological studies. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3698–3703, 2006

Associations between polymer membranes and globular molecules

Polyalkylacrylates (PAA) lamellae have been crystallized in the presence of globular camphor molecules. High resolution images show the two-dimensional lattice image (5 Å) of PAA and patches attributed to camphor molecules. The calculated images prove that camphor molecules are included in this lattice, each one replacing seven alkyl chains of the PAA. The camphor molecules show a short-range order (≈ 40 Å) in the PAA lattice. This order is interpreted in terms of long-range elastic interactions.

Defects in a lamellar polymer by high-resolution electron microscopy

Polyalkylacrylate (PAA) two-dimensional lamellae (30 Å thick) are strongly resistant to the electron beam, so that high-resolution images (4.2 Å) can be obtained. Grain boundaries in the lamella can be visualized, molecular holes are also present in the monocrystalline domains. Single molecular holes have been quantitatively analyzed and averaged. From the kinematical theory, the theoretical images of such defects are calculated and compared to the averaged experimental one. The grain boundaries as well as the molecular holes have been previously predicted from the stereoregularity constraints in the polymer. These forecasts are now experimentally assessed.

Does the conformation of adsorbed fibrinogen dictate platelet interactions with artificial surfaces?

Platelet activation by polymer surfaces is thought to require preliminary adsorption of fibrinogen and perhaps changes in fibrinogen conformation. We measured fibrinogen adsorption by a series of polymers by two methods, using either 125I-labeled fibrinogen or 125I-labeled antifibrinogen antibodies, and correlated the results with platelet reactivity (retention and secretion) in columns of beads coated with the polymers. For polyalkyl methacrylates with 1 to 4 carbon side chains, platelet reactivity varied directly with increasing length of the alkyl side chain and with the quantity of bound fibrinogen recognizable by antifibrinogen antibody but not with the total quantity of fibrinogen adsorbed. The same pattern of results was seen with five antibody preparations, including affinity-purified Fab fragments against the D or E domain of fibrinogen. Tests of platelet retention and fibrinogen binding to four polyalkyl acrylates and to three unrelated polymers (polystyrene, polymethyl methacrylate, and a polyether polyurethane) indicated that platelet retention correlated positively with both total fibrinogen binding and with the amount of antibody-recognizable fibrinogen bound. Drugs that block platelet aggregation, but not adhesion, did not alter the hierarchy of platelet retention to the polyalkyl methacrylates. These data suggest that, contrary to previous views, platelet adhesion to artificial surfaces increases with increasing surface coverage of adsorbed fibrinogen if the bound fibrinogen maintains a conformation such that its functional domains remain recognizable by antibody probes.

Does the Conformation of Adsorbed Fibrinogen Dictate Platelet Interactions With Artificial Surfaces?

Platelet activation by polymer surfaces is thought to require preliminary adsorption of fibrinogen and perhaps changes in fibrinogen conformation. We measured fibrinogen adsorption by a series of polymers by two methods, using either 125I-labeled fibrinogen or 125I-labeled antifibrinogen antibodies, and correlated the results with platelet reactivity (retention and secretion) in columns of beads coated with the polymers. For polyalkyl methacrylates with 1 to 4 carbon side chains, platelet reactivity varied directly with increasing length of the alkyl side chain and with the quantity of bound fibrinogen recognizable by antifibrinogen antibody but not with the total quantity of fibrinogen adsorbed. The same pattern of results was seen with five antibody preparations, including affinity-purified Fab fragments against the D or E domain of fibrinogen. Tests of platelet retention and fibrinogen binding to four polyalkyl acrylates and to three unrelated polymers (polystyrene, polymethyl methacrylate, and a polyether polyurethane) indicated that platelet retention correlated positively with both total fibrinogen binding and with the amount of antibody-recognizable fibrinogen bound. Drugs that block platelet aggregation, but not adhesion, did not alter the hierarchy of platelet retention to the polyalkyl methacrylates. These data suggest that, contrary to previous views, platelet adhesion to artificial surfaces increases with increasing surface coverage of adsorbed fibrinogen if the bound fibrinogen maintains a conformation such that its functional domains remain recognizable by antibody probes.

Dielectric and NMR studies of the molecular movements in comb-like polyfluoro-alkyl acrylates and polyfluoro-alkyl methacrylates

The characteristics of the molecular movements have been studied in a series of polyacrylate and polymethacrylate homologues containing fluoro-alkyl fragments in the branches. The ability of the secondary groups to arrange themselves in an orderly fashion and to crystallize has been shown to apply to the lower homologues; the transition to the highly-elastic state and the melting have shifted into higher temperature ranges when compared with those of the polyalkyl acrylates (PAA) and polyalkyl methacrylates (PAMA). Relaxation processes due to the mobilities of the ester and the polar end groups in the branches, the α-methyl groups, and also the fluoromethylene fragments, have been detected at low temperatures. The comb-like homologues in the series with differing compositions have been found to have dipolar polarization relaxation times of the ester groups at low temperatures which depend to a large extent on the interactions and the arrangement of the side chains.

Rheological properties of comb-like polyalkylacrylates and polyalkylmethacrylates

A study was made of the viscosities of polyalkylacrylate (PA) and polyalkylmethacrylate (PMA) melts containing 4 to 18 carbon atoms in the side chain. It was shown that with an increase in the length of side branches, viscosity and any anomaly in viscosity in homologous series markedly decreases, the viscosity of polymers with the same side radical being higher for PMA, compared with PA. The activation energy of viscous flow E decreases with an increase in the length of the side radical. The maximum corresponds to the first members of the series—polymethylmethacrylate and polymethylacrylate. The value of E for polymers with long alkyl side radicals is equal to the value of E of polypropylene, in contrast to the poly-α-olefin series, for which E corresponds to E of linear polyethylene for higher homologues. It was found that PA and PMA with long side branches capable of being crystallized may flow at temperatures somewhat lower than melting point. The formation of discontinuities is a typical feature of flow curves in this case. It was shown that the formation of this discontinuity is due to the breakdown of crystalline structure of the polymer.

Ultraviolet irradiation of poly(alkyl acrylates) and poly(alkyl methacrylates)

AbstractAcrylic and methacrylic homopolymers containing different side groups were irradiated with ultraviolet light in the presence of air. The changes of molecular weight distributions of the irradiated polymers were analyzed by means of gel permeation chromatography (GPC), and the rates of chain scission and crosslinking were estimated. As the result of this study, it was found that chain scission takes place more easily in polyalkyl methacrylates than in polyalkyl acrylates.

Conformations of Isotactic Polyalkyl Acrylates in Solution Determined by Nuclear Magnetic Resonance

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConformations of Isotactic Polyalkyl Acrylates in Solution Determined by Nuclear Magnetic ResonanceTsuneo Yoshino, Yoshikazu Kikuchi, and Jiro KomiyamaCite this: J. Phys. Chem. 1966, 70, 4, 1059–1063Publication Date (Print):April 1, 1966Publication History Published online1 May 2002Published inissue 1 April 1966https://doi.org/10.1021/j100876a017RIGHTS & PERMISSIONSArticle Views62Altmetric-Citations24LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (470 KB) Get e-Alerts

Analysis of the solubility behaviour of irradiated polyethylene and other polymers

The equation for the sol fraction ( s ) of a cross-linked polymer network becomes readily tractable when applied to special cases of the generalized distribution function n( u ) = C ( u/u 1 ) λ -1 exp ( — λu/u 1 ). For values of λ = ∞, 1 and 0 respectively, this function yields the uniform distribution, the exponential distribution and a hypothetical pseudo-random distribution. Assuming that cross-linking and fracture occur at random and in proportion to the radiation dose, simple expressions are derived relating sol fraction to radiation dose ( r ) for each of the three distributions. The most useful of these is the relation involving the fracture density per unit dose ( p 0 ) and the density of cross-linked units per unit dose ( q 0 ). s +√ s = p 0 / q 0 + 1/ q 0 u 1 r . This holds strictly for exponential distributions, whether or not main-chain fracture occurs simultaneously with cross-linking, and also holds at high doses for the other distributions considered, providing that cross-linking is accompanied by fracture. This treatment is applied to experimental results on low-density and high-density polyethylenes, polyvinyl acetates, polyvinyl chloride, polypropylene and polyalkyl acrylates. The relevant radiation parameters p 0 , q 0 and the corresponding G values are deduced. It is found, in the case of polyethylene, that q 0 is, within experimental error independent of the molecular weight, degree of branching or crystallinity, but is affected by the presence of air. Similar values of q 0 are also observed for polyvinyl acetate and polyvinyl chloride.