Ethylene Butylacrylate Copolymer Research Articles

The photostability and peel strength of ethylene butyl acrylate copolymer blends for use in conservation of cultural heritage

Materials, both natural and synthetic, are used as adhesives or consolidants during the conservation of cultural objects. However, few adhesives have been formulated specifically for the needs of cultural heritage. This article describes a study of the stability of ethylene butyl acrylate copolymers as well as blends of these polymers with low molecular weight resins, which may be used as consolidating adhesives for flaking and fragile paint layers. The materials were aged under simulated museum conditions. Fourier-transform infrared spectroscopy and size exclusion chromatography were used to analyze changes in chemical structure and molecular weight distribution, respectively. The degree of degradation was found to be dependent on the specific blend composition. With the addition of a hindered amine light stabilizer, minimal changes occurred in the molecular weight distribution and no loss in polymer solubility were noted. Therefore, it is suggested to incorporate a stabilizer into ethylene butyl acrylate polymer blends to extend their life and safe use in cultural heritage. Differential scanning calorimetry was employed to investigate the miscibility of the binary blends and the temperature window of their application. Furthermore, adhesive peel strength for the individual components and the binary mixtures revealed values comparable to that of Paraloid™ B-72, a frequently used consolidant. Consolidation tests on the blends were done by professional conservators on mock up and dummy paintings.

Green Highly Clay-Filled Polyethylene Composites as Coating Materials for Cable Industry-A New Application Route of Non-Organophilised Natural Montmorillonites in Polymeric Materials.

In order to develop flame retardant and relatively green cable coating materials, polyethylene (PE) was melt blended with 5, 7.5, or 10 wt. % of a natural calcium montmorillonite (C–Ca) pre-dispersed in EBA (ethylene-butyl acrylate copolymer), EVA (ethylene-vinyl acetate copolymer), or mEVA (EVA modified with maleic anhydride). For comparison, an organophilised montmorillonite (CW9) was tested. The main study of composites containing EBA/C–Ca, EVA/C–Ca, and mEVA/CW9 pre-dispersions revealed that both clays were not fully exfoliated in the matrix, however, C–Ca (7.5 wt. %) markedly increased limited oxygen index (LOI) from 18% O2 (PE) up to 22.0% O2. An insignificantly higher LOI value (22.2% O2) was noted for a sample with 10 wt. % of CW9. The fillers did not affect hardness, but spectacularly increased Young’s modulus of the compression-moulded samples (tensile strength and elongation at break values were reduced). Thermal features of the matrix were not unpredictably changed by the clays. Generally, all the tests revealed that PE filled with the chemically untreated natural C–Ca reached similar or better mechanical and thermal features than materials containing the ammonium salt-modified montmorillonite.

Crosslinked ethylene butyl acrylate copolymer foams with different cellular structure interconnectivity and tortuosity: Microstructure and physical properties

ABSTRACTIn this work, the cellular structure, physical properties, and the structure–property relationship of several novel crosslinked ethylene butyl acrylate (EBA) foams with different cellular structure interconnectivity (low tortuosity and high tortuosity) have been analyzed and compared to that of closed cell EBA foams and to that of an open‐cell polyurethane foam. The results have shown that these materials present interesting properties highly dependent on the tortuosity of the cellular structure. In particular, it has been proved that reducing the tortuosity allows enhancing the acoustic absorption, the oil uptake, and the cushioning behavior. On the other hand, increasing tortuosity allows improving the impact behavior. In addition, the new open‐cell materials present an enhanced damping factor for low‐frequency vibrations. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48161.

Nano‐indentation for probing mechanical properties of nanocomposites based on ethylene butyl acrylate copolymer and carbon black

ABSTRACTMechanical properties of heterogeneous systems based on carbon black (CB) filled semi‐crystalline ethylene butyl acrylate (EBA) copolymer nanocomposites are characterized using nano‐indentation technique. The size effect and CB content dependence on the deformation behavior at room temperature were investigated. The phenomenology for hardness response (H) indicates a typical enhancement of the H when the indentation depth (h) decreases as for the usual elastomeric materials. All H–h curves, fitted according to the Meyer's empirical power law and Franck elasticity model, highlight the so‐called length‐scale‐dependent deformation. Similar trend is observed for the elastic modulus. Furthermore, it is evidenced that the increases of CB content increases the mechanical properties of composites, that is, hardness and elastic modulus. This behavior can be mainly related, on the one hand, to the change of the meso‐structure, formed by the interconnected network of polymer and the aggregates of CB particles and to the nature of the polymer matrix, on the other hand. The mechanical properties characterized from micro and submicron indentations were compared to that characterized at macroscopic scale to highlight the possible correlations between the two scales. This investigation can interest many applications of polymer composites for rubber technology such as tires industry, soft robotic, and adhesives. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47897.

Space charge suppression of polyethylene induced by blending with ethylene-butyl acrylate copolymer

High-voltage direct current (HVDC) power cables have been paid more attention due to the big issue concerning the main insulation materials. The residues in the industrial production process will cause space charge generation and accumulation in the materials, which has become one bottleneck to limit the development of power cables up to higher voltage levels. In this paper, the LDPE matrix was modified by three types of ethylene-butyl acrylate (EBA) copolymers (1.0 wt%) with different polarities (BA content) via melt blending to optimize the space charge behavior of the LDPE insulation. The micromorphology and structure of the blends are examined by polarized light microscope and differential scanning calorimetry. The space charge distribution is tested by the pulsed electroacoustic method. The trap level is studied by the thermally stimulated current. The results show that EBA introduces more deep traps and decreases the shallow traps. The medium-polar EBA (16% BA content) can effectively suppress charge accumulation, and have the same suppressed effect on XLPE/EBA blends. This study will provide important insights into the design and development of advanced HVDC power cable applications.

Structure and resultant mechanical and tribological performance of PP/PLA/carbon fiber/ethylene-butyl acrylate composites

The aim of this study is to put forth the synergistic effect of carbon fiber reinforcement and ethylene-butyl acrylate compatibilization on the mechanical and wear performance of polypropylene/poly(lactic acid) blend composites and to find an inspiration about their availability for diverse applications as stronger renewable composites. Crystalline morphologies are greatly affected by these concentrations. Synergistic inclusion of both poly(lactic acid) and ethylene-butyl acrylate copolymer in polypropylene matrix was found to effectively enhance the nucleation of β-crystals which may provide secondary mechanism of reinforcement. Despite the island-sea type immiscible morphology, ethylene-butyl acrylate incorporation offered potential toughening effect for polypropylene/poly(lactic acid) system due to its ethylene molecules which have more flexibility and an elongation than poly(lactic acid). As expected, the increase in carbon fiber concentration in the composites indicated a positive correlation with mechanical test results. However, contrary to ethylene-butyl acrylate compatibilization, high rigidity obtained by carbon fiber contribution was not beneficial from the abrasive wear resistance point of view, due to repeated ploughing effect of the counterpart material.

Polyoxymethylene/ethylene butylacrylate copolymer/ethylene‐methyl acrylate‐glycidyl methacrylate ternary blends

Blends of compatibilized polyoxymethylene (POM)/ethylene butylacrylate copolymer (EBA)/ethylene‐methyl acrylate‐glycidyl methacrylate copolymer (EMA‐GMA) and uncompatibilized POM/EBA were investigated. The notched impact strength of the compatibilized blends was higher than that of their uncompatibilized counterparts. The toughness of the POM blends was improved obviously with relatively low loading of EBA. Fourier transform infrared spectroscopy (FTIR) spectra of EMA‐GMA, pure POM, and POM/EBA/EMA‐GMA blends indicated that epoxy groups of EMA‐GMA reacted with terminal hydroxyl groups of POM molecular chains. The glass‐transition temperature (Tg) values of the POM matrix and the EBA phase were observed shifted to each other in the presence of EMA‐GMA compatibilizer indicating that the compatibilized blends had better compatibility than their uncompatibilized counterparts. With the addition of EBA to POM, both the compatibilized and uncompatibilized blends showed higher onset degradation temperature (Td) than that of pure POM and the Td values of the compatibilized blends were higher than those of their uncompatibilized counterparts. The scanning electron microscopy showed better EBA particles distribution state in the compatibilized system than in the uncompatibilized one. The compatibilized blend with an obvious rougher impact fracture surface indicated the ductile fracture mode. POLYM. ENG. SCI., 58:1127–1134, 2018. © 2017 Society of Plastics Engineers

Mechanical, thermal and morphological properties of poly(lactic acid)/ethylene-butyl acrylate copolymer nanocomposites

This paper reports a melt blend of poly(lactic acid) (PLA)/ethylene-butyl acrylate copolymer (EBAC) with organoclay content at 3 phr. The mechanical, thermal and morphological properties of PLA/EBAC blends and nanocomposites were investigated. The morphological analysis revealed EBAC phase dispersed as a spherical domain in PLA matrix and the domain size of EBAC dispersed phase increased with increasing EBAC content. The addition of organoclay could improve the miscibility of PLA/EBAC blends due to the decrease of domain size of EBAC dispersed phase. The mechanical properties indicated that the strain at break and impact strength of PLA increased when added EBAC, but Young’s modulus and tensile strength decreased. Storage modulus increased with the addition of organoclay to the PLA/EBAC blends. The thermal properties found that the incorporation of organoclay in the PLA/EBAC blends did not effect on the glass transition temperature and melting temperature values relative to PLA. The degradation temperature of PLA improved with the addition of EBAC. This indicated that EBAC has more thermal stability and degradation temperature than PLA. From X-ray diffraction patterns displayed the characteristic peak in PLA/EBAC/organoclay nanocomposites appeared at the lower angle, which indicated the dispersed clay is intercalated in the polymer matrix. However, second-order diffraction peak appeared at the higher angle indicated that there was partially the conventional composite.

New blends of ethylene-butyl acrylate copolymers with thermoplastic starch. Characterization and bacterial biodegradation

Ethylene-butyl acrylate copolymer (EBA) with 13% of butyl acrylate content was used to produce blends with 10, 30 and 60% of thermoplastic starch (TPS) plasticized with glycerol. Ethylene-acrylic acid copolymer (EAA) was used as compatibilizer at 20% content with respect to EBA. The blends were characterized by X-ray diffraction, ATR-Fourier Transform Infrared Spectroscopy (ATR-FTIR), Scanning Electron Microscopy (SEM), water-Contact Angle measurements (CA), Differential Scanning Calorimetry (DSC) and Stress–strain mechanical tests. Initiated autoxidation of the polymer blends was studied by chemiluminescence (CL) confirming that the presence of the polyolefin-TPS interphase did not substantially affect the oxidative thermostability of the materials. Three bacterial species have been isolated from the blend films buried in soil and identified as Bacillus subtilis, Bacillus borstelensis and Bacillus licheniformis. Biodegradation of the blends (28days at 45°C) was evaluated by carbon dioxide measurement using the indirect impedance technique.

Photostabilization study of ethylene-butyl acrylate copolymers functionalized in the molten state with hindered amine light stabilizers (HALS)

Hindered Amine Light Stabilizers (HALS), N-methylated and O-alkylhydroxylamine, were successfully anchored onto an ethylene-co-butyl acrylate (BA) by a transesterification reaction in the molten state. The content of HALS bonded to the EBA was calculated from the atomic ratio (N/C) determined by X-ray Photoelectron Spectroscopy (XPS). After reaction times of 5–30 min in the molten state the content of bonded HALS attained values from 0.17 to 0.63%. The modified EBA with HALS were studied by Chemiluminescence emission and the photostabilization effect was evaluated under accelerated ageing in the presence of pesticides. The antioxidant effect of HALS bonded to EBA was evaluated by determination of Carbonyl Index (CI) and retention of elongation at break as a function of exposure time and pesticide treatment. The stability of the EBA with anchored HALS exhibited higher performance as shown by low CI-values and correlated with the content of bound HALS and the thermal history of the materials. Also, mechanical properties correlated well with the CI results and the photostabilization of bound HALS was effective until 3150 h of exposure time using pesticides.

Electrical conductivity studies on carbon black loaded ethylene butylacrylate polymer composites

In this work we studied the electrical properties of carbon black mixed into ethylene butylacrylate copolymer, using impedance spectroscopy, in the frequency range from 100Hz to 100kHz and over the temperature range from 150 to 360K. A series of samples was prepared with several filler contents, below and above the percolation threshold, which was calculated using direct current conductivity measurements. For concentrations below the critical concentration the negative temperature coefficient in resistivity effect is observed, and for concentrations above that threshold the positive temperature coefficient in resistivity effect is present. The dielectric response was analyzed using complex permittivity or modulus formalisms, depending on the concentration of filler in the polymer matrix. Havriliak–Negami model was used to fit the experimental results.

Electric Modulus Analysis of Carbon Black/Copolymer Composite Materials

We have investigated the electrical properties of carbon black (CB) loaded in ethylene butylacrylate copolymer composite (EBA) in the frequency range between 102 and 104 Hz and temperature range between 153 and 353 K. The frequency dependence of electrical data that have been analyzed in two frameworks: the electrical modulus formalism with the Kohlrausch-Williams-Watts stretched exponential function (KWW) and the electrical conductivity by using the Jonscher’s power law in the frequency domain. The stretching exponent βKWW and n are found to be temperature independent for all CB fractions and to be decreased when the CB volume concentrations loaded in copolymer matrix increases. It is found that the activation energy obtained by the modulus method is in good agreement with that obtained by the DC conductivity in the power law which is independent on the CB contents that exist in the copolymer matrix, suggesting that these particles do not interact significantly with the chain segments of the macromolecules in the EBA copolymer.

Characterization of Ethylene methyl methacrylate and Ethylene butylacrylate Copolymers with Interactive Liquid Chromatography

AbstractSummary: Copolymers of ethylene with methyl methacrylate (EMMA) and butyl acrylate (EBA), which are of different average chemical composition and block lengths according to NMR analysis, were analyzed by size exclusion chromatography (SEC), differential scanning calorimetry (DSC), Crystallization Analysis Fractionation (CRYSTAF), and high performance liquid chromatography at high temperature (HT‐HPLC). With CRYSTAF and DSC crystallizing fractions were detected only in some samples. HT‐HPLC fractionated all the samples irrespective of their crystallinity. Homopolymers, PMMA and PE were also found in the copolymer samples of EMMA. EMMA and EBA were separated in HPLC according to the content of polar comonomer. A linear correlation between the MMA content and elution volume could not be established due to the presence of homopolymers as admixtures. In such a case the average chemical composition obtained by NMR does not correspond to the real chemical composition of the copolymers. Unlike EMMA the EBA samples eluted in single peaks, which was used for evaluation of their chemical composition distribution. The comparison of results obtained by fractionation via CRYSTAF and HT‐HPLC clearly demonstrates the advantages of the chromatographic approach to study the chemical heterogeneity of olefin based copolymers.

PTCR effect in carbon black/copolymer composites

Some materials show an abrupt increase in resistivity when the temperature changes only over a few degrees. This phenomenon, known as PTCR effect (positive temperature coefficient of resistivity), has been largely studied in the last few years, due to its potential applications in industry. Particularly, it can be used in auto controlled heaters, temperature sensors, protection circuits and in security systems for power electronic circuits. In this work we present the study of the electrical properties of the percolating system carbon black particles filled with ethylene butylacrylate copolymer composite (EBA), in the temperature range from −100 to 100 °C and in frequencies between 10 Hz and 100 kHz. The PTCR effect was observed at temperatures slightly above the room temperature, for concentrations higher than that of the percolation critical concentration. The mechanism responsible for the change in resistivity, at this stage, is predominantly tunnelling, wherein the conductive filler particles are not in physical contact, and the electrons tunnel through the insulating gap between them. At low temperatures, such as below and close to the glass transition temperature, the DC conductivity obeys the Arrhenius law. The calculated activation energy values are independent of carbon black contents inside the copolymer matrix, suggesting that these particles do not interact significantly with the chain segments of the macromolecules in the EBA copolymer.

Electric modulus-based analysis of the dielectric relaxation in carbon black loaded polymer composites

A thorough investigation of the ac electrical properties of carbon black (CB) mixed into ethylene butylacrylate copolymer has been conducted using ac impedance spectroscopy in the frequency range 10 Hz–100 kHz and over the temperature range of 150 (Tg−48 K)–319 (Tg+121 K) K. For this investigation, a series of eight samples were prepared with various filler contents above the percolation threshold. Using the electric modulus formalism it has been found that the Cole–Cole equation of dielectric relaxation expressed in the electric modulus form is capable of quantitatively describing the experimental data from which we extract the relaxation time and a parameter α which gauges the broadening of the loss spectrum. The small values of α ranging from 0.06 to 0.10 suggest a behavior close to the state of a single relaxation time. Furthermore, the relaxation time as a function of temperature is characterized by an Arrhenius behavior. While the effective activation energy is on the order of 60 meV and is insensitive to CB volume fraction, the Arrhenius prefactor is found to strongly depend on this volume fraction. The observed relaxation mechanism does not result simply from thermally activated dipolar interactions but is a collective cooperative effect of the CB mesostructure.

A TGA-FTIR study on the effect of CaCO 3 on the thermal degradation of EBA copolymer

The thermal degradation of ethylene–butyl acrylate (EBA) copolymer with/without CaCO 3 has been studied via the combined TGA-FTIR technique at a heating rate of 10 °C/min in high purified N 2. The volatiles from EBA on heating include mainly 1-alkene (i.e. 1-butene), hydrocarbon chain fragments, CO 2, butyl acrylate-containing fragment, as well as the trace of CO and H 2O in the temperature range of 350–500 °C. The 1-butene is most likely formed through ester pyrolysis. The two bands at 2925 cm −1 (asymmetric stretching of –CH 2 –, corresponding to hydrocarbon chain fragments), and 720 cm −1 (plane rocking of –CH 2–, representative of the alkanes with low molecular weight –(CH 2) n –, n ≥ 4) were indicative of the hydrocarbon species essentially accompanied with acrylate-containing fragments at high temperature. Based on the data message of the TGA and the Gram–Schmidt curves, it shows that the EBA copolymer becomes much more stable in the presence of CaCO 3. The volatiles involved in the pyrolysis of EBA copolymer have qualitatively chemical composition similar to the case with CaCO 3. Obviously, both the descending flammable volatiles and the ascending creation in CO 2 from EBA copolymer do come intimately from the interposition of CaCO 3. That both the prolonged ignition time and the reduced heat release rate of EBA during combustion depend, therefore, on the presence of CaCO 3 is being expected.

Stress induced cracks in carbon black filled elastomers probed by atomic force microscopy

In the current study, carbon black (CB) filled ethylene butylacrylate copolymer samples, which are submitted to a uniaxial creep, are probed with a sub-100-nm spatial resolution using atomic force microscopy in tapping mode. We demonstrate the significant effect of the long-time application of stress, at low strain amplitude well below the breaking threshold, on the crack occurrence along the interfaces between polymer and CB aggregates. The data analysis indicates a log-normal distribution of crack width whose average value follows an exponential saturation as a function of aging time. A possible model realizing this behavior is the rate dependent theory of fracture for polymers.

Influence of clays on the flame retardancy and high temperature viscoelastic properties of polymeric intumescent formulations

A natural Brazilian montmorillonite clay was submitted to organophilization treatments to evaluate the effect of these treatments on the flame retardancy potential of polymer composites containing an intumescent ammonium polyphosphate and pentaerythritol formulation. An ethylene–butyl acrylate copolymer was used as the polymer matrix. Natural or organophilic clays were added both to the pure polymer and to the polymer containing the intumescent mixture. The influence of these mineral fillers, and of their organophilization treatments, on flame retardancy was investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL-94 rating standard, heating microscopy, rheological measurements and cone calorimetry. The results show that these inorganic additives have a synergistic effect on composites containing the intumescent formulation.

Mechanical fatigue and dielectric relaxation of carbon black/polymer composites

Using a home-built experimental setup, we investigate the carbon black (CB) volume fraction-resolved, time-resolved, and frequency-resolved spectra of the room temperature (well above the glass transition temperature of the matrix) effective complex permittivity of well characterized CB filled ethylene butylacrylate copolymer samples that are submitted to a uniaxial tension. We focus here on three samples with CB volume fraction less, near, and well away the percolation threshold at about 8 vol %. Our primary observation is that the temporal evolution of the real and imaginary parts of the effective permittivity is distinctly different for samples containing a CB volume fraction below and above percolation threshold. For samples containing a CB volume fraction below and close to the percolation threshold, and at a given frequency, ε′ and ε″ remain constant over the time scale of our measurements. For the sample containing a CB volume fraction above the percolation threshold the evolution of ε′ and ε″ is different in the low and high elongation ratio regimes. At low strain, the temporal evolution of permittivity during aging under stress shows a logarithmic growth phase followed by a logarithmic decay phase, whereas for sufficiently large strain the permittivity behaviors coincide with those observed below the percolation threshold. To explain the issues involved, we argue that the phenomenology for physical aging in these materials is related to the change in the mesostructure, formed by the heterogeneous three-dimensional interconnected network of polymer and of aggregates (or agglomerates) of CB particles, as the composite is stretched. Indeed, it is possible to argue qualitatively that below the percolation threshold the time-independent permittivity behavior is reminiscent to the elasticity network properties of the polymeric matrix. The reorientation and breakdown of the CB aggregates are believed to be crucial for the physical aging understanding above the percolation threshold and low strain. An examination of the surface and volume morphological evolutions of these materials under the action of a mechanical stress at the microscale by scanning electron microscopy and atomic force microscopy indicates that aging during a few hundreds of hours, even at a moderate strain, generates voids and cracks that are aligned along the stretching direction. The overall behavior is compared to what occurs in another type of filled polymer system, i.e., plastoferrites, for which it was recently discovered that two characteristic time scales are required to describe physical aging.

Influence of uniaxial tension on the microwave absorption properties of filled polymers

The evolution of the frequency-dependent absorption spectra for plastoferrites and carbon black-filled ethylene butylacrylate copolymer composites subjected to a uniaxial tension is evaluated using a vector network analyzer as a function of the elongation ratio over the frequency range of 0.3–5 GHz and at room temperature. The absorption spectrum has a double-peaked structure with two broad and symmetrical components. The positions of the lower-frequency peak (1.5 GHz) and the higher-frequency (≅4±0.3 GHz) do not change with extension over the considered range of strain, however, their relative absorption energy changes versus tensile stress can be explained in terms of a Gaussian molecular network model (affine behavior) provided that the elasticity network in the material occurs in a manner that is topologically similar to the elasticity network of a conventional rubber. The sensitivity of the microwave absorption to elongation ratio can be exploited to provide artificially structured materials with tunable electromagnetic properties.