Ethylene-methacrylic Acid Research Articles

Very long-time crystallization kinetics for ethylene-methacrylic acid ionomers neutralized with zinc, sodium, lithium and magnesium

Papers by our group [1] (Grady et al., 2013) and another group [2] (Paul et al. 2012) examined crystallization of random copolymers of ethylene and methacrylic acid after room temperature annealing. Similar conclusions were reached concerning the crystallization process; primary crystals were either unchanged or changed very little after annealing while secondary crystallization occurred over long time scales after annealing. The current work confirms these general conclusions for four different cations (Zn2+, Na+, Li+ and Mg2+), with the latter two not studied in either of the previous studies. Even after 6 years of annealing at room temperature, the crystallization rate is constant with logarithmic time, i.e. the material continues to crystallize. The acid copolymer does not crystallize with room temperature annealing, although secondary crystals of the acid copolymer thicken with annealing.

Strengthening ethylene-methacrylic acid ionomers with single-boron-based molecules as cross-linkers in dynamic networking

This work has developed strengthened ethylene-methacrylic acid ionomers by employing single-boron compounds as readily available cross-linkers.

Exploring shape memory and self-healing behavior in sodium and zinc neutralized ethylene/methacrylic acid (EMAA) ionomers

Polymeric materials with self-healing and shape memory capabilities have gained increasing attention for their potential applications across various industries. In this study, zinc and sodium ionomers were systematically investigated using a multi-faceted approach, including rheological analysis, Fourier-transform infrared spectroscopy (FTIR), dynamic mechanical thermal analysis (DMTA), X-ray diffraction (XRD), and self-healing and shape memory assessments. Rheological analysis revealed distinct viscosity profiles among the ionomers, with EMAA-Zn 1706 exhibiting higher viscosity at low frequencies and a pronounced thinning behavior across the frequency range. FTIR analysis provided insights into the ionomers' molecular structures and functional groups. DMTA results illuminated the viscoelastic behavior and phase transitions of the ionomers. Peaks in the tan delta curve indicated order-disorder transitions and crystalline melting temperatures, influencing their mechanical properties. XRD patterns revealed low-angle peaks associated with clusters or localized regions within the ionomers. Additionally, characteristic peaks pointed to degrees of crystallinity and ordered packing. Self-healing assessments demonstrated varying healing efficiencies, with values ranging from 40 % to 60 % for EMAA-Zn 9945 and EMAA-Na 2000, while EMAA-Zn 1706 exhibited lower healing efficiency, not surpassing 20 %, attributed to its distinct rheological characteristics. Shape memory experiments were conducted in both torsion and fold-deploy modes, revealing remarkable shape fixations, with all ionomers exceeding 99 % in torsion and 95 % in the fold-deploy method. In aqueous environments, shape memory returns remained above 90 %, underscoring the water's influence on the shape memory effect. The exceptional shape memory performances and varying self-healing efficiencies of these ionomers highlight their versatility and significance in addressing practical challenges, paving the way for tailored materials with promising applications in numerous fields.

Versatility assessment of supercritical CO2 delamination for photovoltaic modules with ethylene-vinyl acetate, polyolefin or ethylene methacrylic acid ionomer as encapsulating polymer

The volume of end-of-life photovoltaic panels to be managed will increase considerably over the next decade. In the context of an environmentally friendly circular economy, it is becoming more than necessary to develop efficient recycling processes. In this context, a delamination process using supercritical CO2 was studied for the recycling of end-of-life photovoltaic modules. The process studied in this work consists of a CO2 absorption phase within the encapsulating polymer at a pressure level followed by a rapid depressurization leading to the foaming of the polymer. This foaming phenomenon leads to a loss of adhesion at the interfaces of the foamed polymer. Using a systematic experimental protocol, the minimum effective CO2 temperature and pressure are determined for three various encapsulating polymers: an ethylene-vinyl acetate, a polyolefin and an ethylene methacrylic acid ionomer. Based on this parametric optimization, the levels of separation induced by SC-CO2 foaming at the interfaces of these encapsulating polymers in photovoltaic modules are compared. SC-CO2 treatment therefore seems promising for the delamination of first generation photovoltaic modules and future generations of high efficiency perovskite-based photovoltaic modules containing ionomers. However, the results for the polyolefin indicate that SC-CO2 treatment is less effective when the encapsulating polymers do not containing CO2-philic groups.

Synergistic ionic interactions in EMAA ionomer blends: A rheological and mechanical property investigation

The rheological and mechanical (tensile) properties of ethylene methacrylic acid (EMAA) ionomers neutralized by Na, Li, and Zn are investigated in binary combinations of two pure ionomers with different counterions. Molecular weight, methacrylic acid content, degree of neutralization, and ion type are tested as experimental parameters to investigate the composition that leads to the largest enhancement in rheological and mechanical properties. Binary cation blend components with low molecular weight and high neutralization reveal enhancement in rheological and mechanical properties beyond a linear mixing combination of material properties such as zero-shear viscosity, relaxation time, and Young’s modulus. The sticky reptation model is applied to EMAA ionomer blends of binary counterions to calculate the timescales of chain dynamics delayed by ionic associations. The ionic clusters of binary cations have longer-lasting ionic associations forming a reinforced reversible crosslink network. The experimental analysis consists of linear and nonlinear viscoelastic experiments, uniaxial extension, and dynamic mechanical analysis, which reveal the conditions and extent of synergism seen in binary EMAA ionomer blends.

Enabling contactless rapid on-demand debonding and rebonding using hysteresis heating of ferrimagnetic nanoparticles

Rapid and contactless on-demand debonding and rebonding of high-strength joints is a promising solution for quick attachment, repairs, disassembly, and recycling of structural systems. Herein we show that rapid and contactless on-demand debonding and rebonding can be achieved by incorporating ferrimagnetic iron oxide nanoparticles (Fe3O4) into poly(ethylene-methacrylic acid) (EMAA). When subjected to an external alternating magnetic field, the ferrimagnetic nanoparticles generate localized heat which melt the EMMAA, resulting in quick (<1 min) debonding and rebonding. The strength of the adhesive bond matches that achieved by conventional oven heating, exceeding the highest value reported for reversible adhesives in the literature. The results also show that, for the first time, the ferrimagnetic nanoparticles are effective in retaining 100% of the original bond strength for up to five cycles of repeated debonding and rebonding. Analytical and computational models have been developed to characterize the effects of key design parameters, such as Fe3O4 mass loading and magnetic flux on the heating performance and bond strength. The model correlates well with experimental results and reveals that magnetic hysteresis loss is more efficient than eddy current generated by conductive fillers for heating the adhesive. The high-strength EMAA/Fe3O4 adhesive is a very promising solution for contactless, on-demand, repeated adhesion applications to complex geometries and in hard-to-access locations.

HEAT-TRIGGERED SHAPE MEMORY EFFECT OF PEROXIDE CROSS-LINKED ETHYLENE–METHACRYLIC ACID COPOLYMER/NITRILE–BUTADIENE RUBBER THERMOPLASTIC VULCANIZATES WITH SEA-ISLAND STRUCTURE

ABSTRACTDesigning shape memory polymers (SMPs) based on thermoplastic vulcanizates (TPVs) is an essential research topic. An efficient SMP is designed with typical sea-island structured ethylene–methacrylic acid copolymer/nitrile–butadiene rubber (EMA/NBR) TPVs in which the heat-control switched phase performed by the EMA phase is related to the shape fixity ability. The results show that the heat-triggered SMPs exhibit surprising shape memory properties (shape fixity &amp;gt;95%, shape recovery &amp;gt;95%, and fast recovery speed &amp;lt;30 s at the switching temperature of 95 °C). Through X-ray diffraction characterization, it is seen that the shape fixity of TPVs is achieved mainly through ethylene crystallization. The switching temperature is largely determined by the melting temperature (98 °C) obtained by differential scanning calorimetery.

A healable polyethylene adhesive using poly(ethylene methacrylic acid) (EMAA) for three-layer pipe coatings

Poly(ethylene methacrylic acid) (EMAA) has been used here as a thermally activated healing agent (HA) in three layered polyolefinic (3LPO) pipe coatings for the first time. The EMAA (HA) is blended with a linear low density polyethylene (LLDPE) modified with maleic anhydride (MAH) to create a healable multi-functional adhesive (HAMA), which is used to bind the fusion bonded epoxy primer and high density polyethylene topcoat layers together. Different compositions of the HA and modified adhesive were trialled for their healing efficiency using three different healing conditions to explore the effect of increasing temperature and applied load or force. The standard healing protocol used a healing temperature of 110 °C and an applied load of 120 N for 60 min. A high temperature variant increased the temperature to 120 °C while a high load variant increased the applied force to 240 N. Using a 1:1 HAMA adhesive, healing efficiencies of about 70% were achieved for the standard healing condition. Increasing the applied load to 240 N decreased healing to between 64% and 68% depending on the healing measurement, but at 120 °C healing increased to between 82% and 84%. Regardless of the healing condition, overall healing efficiency increased with increasing EMAA (HA) concentration. This study also provided insight into the healing mechanism of the HAMA adhesives by highlighting some necessary features for healing. A bi-phasic microstructure consisting of large EMAA nodules with sufficient adhesion to the MAH-modified LLDPE was identified as being critical. Furthermore, increasing healing temperature increased healing efficiency due to the enhanced flow of EMAA and increased mobility of the polyethylene. Although these results are preliminary in nature, they do provide significant promise that multifunctional HAMA adhesives can be applied as simple, effective and repeatable 3LPO self-healing pipe coatings.

Preparation of Polyethylene and Ethylene/Methacrylic Acid Copolymer Blend Films with Tunable Surface Properties through Manipulating Processing Parameters during Film Blowing.

Polymer films based on polyethylene (PE) and ionomer ethylene/methacrylic acid (EMAA) copolymer blend were prepared by film blowing, whose surface properties were tuned by varying processing parameters, i.e., take up ratio (TUR). Blends of PE/EMAA copolymer were firstly prepared by the melt-mixing method, before being further blown to films. The wettability of the film was investigated by measuring the contact angle/water-film encounter time, and optical properties, i.e., the haze and transmittance. The wettability was found to be enhanced with the increase of TUR. So too was the haze, while the transmittance was found to be almost independent of TUR. The XPS and AFM results directly show the increasing polar functional groups (–COO−) on the surface and roughness with increasing TUR. Further analysis of the 2D SAXS and WAXS unveiled the origin of the invariant transmittance, which resulted from the minor change of the crystallinity and the monotonic increase of the haze, with TUR resulting from the evolution of crystal orientation. In addition to other post-modification methods, the current study provides an alternative route to prepare large-scale PE films as the template for the advanced potential applications, i.e., covering in the layer of roof, the privacy of protective windows, and multitudes of packaging.

Recovery of Mode I self-healing interlaminar fracture toughness of fiber metal laminate by modified double cantilever beam test

Abstract Fiber metal laminate (FML) is a sandwich combination of thin metal and a composite layer which possess high fatigue, creep, and corrosion resistance. The performance of FML depends on the bonding behavior between the metal and composite interface (MCI). Introducing Redux 335k polymer interleaf can improve MCI, but cannot retain the mechanical properties after its first delamination. Toughened self-healing co-polymer film EMAA (Ethylene-methacrylic acid) can be used as an alternative due to its self-healing property which can recover the mechanical property after each delamination. Double-cantilever-beam (DCB) test is carried out by supporting a thick CFRP composite as a backing beam to avoid the yielding of thin metal in FML to estimate the interlaminar fracture toughness (G1C) at the MCI. Results from the DCB test shows that the incorporation of EMAA thin film improves G1C at the MCI. However, G1C gradually decreases despite recovering its fracture toughness after each delamination when the self-healing reaction is thermally activated. The Mode I fracture toughness of EMAA before the first heal is 1.95 kJ/m2, which is higher due to its thermoplastic nature. This article emphasizes only on the recovery of Mode I self-healing efficiency of EMAA at MCI. However, the article also shows the fracture toughness at MCI by using non-self-healing film adhesive at MCI. This comparison is to understand that the standard structural adhesive (Redux 335K) cannot retain the mechanical properties after its first delamination, and also to understand the failure modes of both thermosetting and thermoplastic interleaf at MCI.

Dynamically vulcanized ethylene-methacrylic acid copolymer/nitrile butadiene rubber blends reinforced by zinc dimethacrylate

Thermoplastic vulcanizates (TPVs) based on ethylene-methacrylic acid (EMA) copolymer/nitrile butadiene rubber (NBR) blends were prepared by dynamic vulcanization where the NBR phase was reinforced by zinc dimethacrylate (ZDMA). The effect of ZDMA dosage on the mechanical properties, Mullins effect, and morphology of the TPVs was investigated systematically. Experimental results indicated that the mechanical properties of EMA/NBR TPVs were enhanced remarkably with the incorporation of ZDMA. Morphology study showed that the NBR particles with diameters of about 1–5 μm were dispersed evenly in the etched surface of EMA/NBR/ZDMA TPV. The Mullins effect could be observed in the stress–strain curves of EMA/NBR TPV and EMA/NBR/ZDMA TPV during the uniaxial loading–unloading cycles. Compared with those of EMA/NBR TPV, EMA/NBR/ZDMA TPV had the higher stress, residual deformation, and internal friction loss.

Influence of Ethylene-Methacrylic Acid Copolymer on Thermo-mechanical, Morphological and Rheological Properties of Recycled PET/SEBS Blend

Owing to its properties, poly(ethylene terephthalate) (PET) became one of the most widely used plastic after olefins having applications mainly in packaging industry and ironically has contributed approximately 80 % part of solid waste. This generates a huge amount of waste which piles up in the environment. The processing and end-use cause thermal and mechanical degradation of PET which is then overcome by either blending or by incorporation of fillers. The use of recycled PET as a reinforcement component in elastomers enhances the performance of the resultant blend. The present work describes the preparation, processing and characterization of blend based on SEBS and recycled PET. Addition of 25 % rPET into SEBS matrix results in 31 % rise in tensile strength. The blend was further compatibilized using EMAA. Addition of 10 phr EMAA into the optimized system leads to 42.37 % increment in tensile strength. Further studies from results were analyzed at microscopic scale (SEM, DSC, TGA) and macroscopic scale (rheology and mechanical properties).

Structure, properties and interactions in ionomer/lignin blends

Blends were prepared from lignin and ionomers, i.e. ethylene-methacrylic acid copolymers partially neutralized with inorganic salts for the first time in order to check the possible effect of ionic bonds on the structure and properties of the blends. A low density polyethylene and an ethylene-acrylic acid copolymer without any neutralization were used as references. The lignin content of the blends varied between 0 and 60 vol%. The components were homogenized in an internal mixer and the blends were characterized by various methods including dynamic mechanical analysis, differential scanning calorimetry and tensile testing. The size of dispersed lignin particles was determined from scanning electron micrographs, and component interactions were estimated quantitatively. The properties of ionomer/lignin blends indicated the development of strong interactions between the components. The simultaneous action of hydrogen bonds of non-neutralized methacrylic acid moieties and ionic bonds resulted in the formation of small, dispersed lignin particles of the size of several tenth of a micron. Surprisingly, hydrogen bridges improve interactions and compatibility more than ionic bonds. Contrary to most blends prepared from other polymers, ionomer/lignin blends can be produced with a reasonable combination of properties at moderate lignin contents.

Thermoplastic Vulcanizate Based on Poly(lactic acid) and Acrylic Rubber Blended with Ethylene Ionomer

ABSTRACTA new thermoplastic vulcanizate (TPV) was developed by meltblending of poly(lactic acid) (PLA), acrylic rubber (ACM), and ethylene-methacrylic acid with sodium ions (EMAA-Na). The PLA/ACM/EMAA-Na blend showed low-yield strength, low modulus, and excellent strain recovery. It also demonstrated an increase in complex viscosity and decrease in melting temperature due to the interfacial reaction between the PLA and the ACM phases. The Fourier transform infrared spectroscopy results indicate that EMAA-Na can interact with both PLA and ACM, and that the Na+ ions act as a catalyst for the interfacial reaction between PLA and ACM, while PLA does not react with ACM without EMAA-Na. Moreover, the tensile strength at break of the PLA/ACM/EMAA-Na blend was observed to be extremely improved by the addition of hexamethylenediaminecarbamate (HMDC) due to the increasing of the cross-link density inside the rubber phase. The morphology of the PLA/ACM/EMAA-Na blend with HMDC was finer than that of PLA/ACM/EMAA-Na without HMDC. From the results, it is suggested that the interfacial reaction between the PLA and the ACM phases, the cross-linking in the ACM phase, and the finer morphology improved the mechanical properties of the blend.

Prospective improvements for safer fuel tanks: Experimental tests

In past studies, some of the authors presented how the integration of different systems, for the prevention of fires or explosions due to impact or bullet damage, may significantly improve the safety of fuel tanks. Leakage, after bullet penetration or debris impact, can be significantly reduced by introducing polymeric materials with self-healing capabilities for the container’s walls, while an internal aluminium filler can reduce the sloshing and the danger of fuel ignition. In the present paper, an experimental evaluation of the proposed solution is presented. A ballistic test campaign on a fluid container was performed to investigate the interaction between an ethylene–methacrylic acid (EMAA)-based ionomeric wall (i.e. Dupont ® Surlyn 8940) and an internal aluminium filler (i.e. Explosafe ® ). Results show that the presence of the fluid increases the self-healing capabilities, which are however slightly affected by the internal aluminium filler; the contribution in terms of sloshing reduction remains relevant. Moreover, additional configurations based on multilayer panels are presented. The authors studied the healing process of EMAA in a sandwich configuration made of one skin of ionomer and one skin of carbon fibre, sepa rated by an aramidic honeycomb. The main objective of the honeycomb is to prevent the remarkable reduction of the healing capabilities observed when ionomer is directly coupled to aramidic fabric or composite panels. The new multilayer configurations have been tested at different impact conditions.

Bioimprinting Based Scaffold Development for Tissue Engineering Applications

In this article we report the development of scaffold mimicking the cell surface topography. Using Soft lithography, in which polymer (triglyme, ethylene glycol dimethacrylate, methacrylic acid and IRGAcure 2022) is applied over the cultured cell and cured instantly using UV source. IRGA cure 2022 is a photoinitiator, which helps in solidification of the polymer when exposed to UV light source. Triglyme helps to increase the viscosity of the polymer. This method can be applied to all adherent cells. This scaffold consists of cell surface topography features. The developed scaffold can pave way in tissue engineering for various applications and cell research investigations.

Thermoplastic Elastomer by Terpolymer Reactive Blending of Polyamide-6, Ethylene-1-Butene Rubber and Ethylene Ionomer

Reactive blending of polyamide-6 (PA6), maleic anhydride grafted ethylene-1-butene copolymer (EB-g-MAH) and ethylene-methacrylic acid ionomer partially neutralized by sodium ions (EMAA-Na) was performed to obtain a heat and oil resistant thermoplastic elastomer (TPE). The strain at break of the PA6/EB-g-MAH (40/60) was clearly higher than that of the PA6/EB (40/60). Addition of 2 wt% of EMAA-Na to the PA6/EB-g-MAH (38/60) blend induced an increase of the tensile modulus. TEM images confirmed that the PA6 was the matrix phase in the PA6/EB-g-MAH (40/60) blend, while the EB rubber phase was the matrix in the PA6/EB (40/60) blend. It was considered that the reaction between amino end groups of PA6 and maleic anhydride in EB-g-MAH induced the significant change of blend morphology. The PA6/EB-g-MAH/EMAA-Na blend showed similar morphology with the PA6/EB-g-MAH blend, and the EMAA-Na was expected to be located within the EB-g-MAH phase. It was found that ionic aggregates were formed in the EB-g-MAH phase by neutralization of the hydrated EB-g-MAH with sodium ions. The change of the mechanical properties by addition of EMAA-Na was due to the ionic aggregate formation which acted as physical crosslinks in the EB-g-MAH phase.

Piezoelectric and mechanical properties of fatigue resistant, self-healing PZT–ionomer composites

Piezoelectric ceramic–polymer composites with 0–3 connectivity were fabricated using lead zirconium titanate (PZT) powder dispersed in an ionomer (Zn ionomer) and its reference ethylene methacrylic acid copolymer (EMAA) polymer matrix. The PZT–Zn ionomer and PZT–EMAA composites were prepared by melt extrusion followed by hot pressing. The effects of poling conditions such as temperature, time and electric field on the piezoelectric properties of the composites were investigated. The experimentally observed piezoelectric charge coefficient and dielectric constant of the composites were compared with theoretical models. The results show that PZT–Zn ionomer composites have better piezoelectric properties compared to PZT–EMAA composites. The static and fatigue properties of the composites were investigated. The PZT–Zn ionomer composites were found to have excellent fatigue resistance even at strain levels of 4%. Due to the self-healing capabilities of the ionomer matrix, the loss of piezoelectric properties after high strain tensile cyclic loading could be partially recovered by thermal healing.

Antimicrobial silica particles loaded with quaternary ammonium polyethyleneimine network

Silica particles functionalized with quaternary ammonium groups were prepared by interpenetrating polyethylenimine (PEI) into silica particles and crosslinking with diiodopentane, followed by octyliodide alkylation and methyliodide quaternarization (S‐QA‐PEI). The synthesized S‐QA‐PEI particles were identified with a slight particle size increase of 2–3 µm. Different ratios of PEI:silica particles were prepared and analyzed. While silica particles are negatively charged, −16.7 ± 5.11 mV, the prepared S‐QA‐PEI particles are positively charged, +50–60 mV. These particles were embedded in poly(ethylene vinyl acetate) and poly(ethylene methacrylic acid) coatings which exhibited strong antibacterial activity. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Analysis of EMAA Splats on Glass and Mild Steel Substrates

Thermal spray coatings are composed of millions of heated particles driven at high velocities onto a substrate, thereby building up and forming a consolidated coating. Thus, investigating single solidified droplets contributes to the fundamental understanding of the evolution of a surface coating and its properties. In this study, the single splat morphology and thermal characteristics of flame-sprayed ethylene methacrylic acid (EMAA) splats, deposited at various stand-off distances onto glass and mild steel substrates, are investigated using scanning electron microscopy, differential scanning calorimetry, and thermal gravimetric analysis. This study indicates that the microstructure of EMAA coatings can be controlled by judicially selecting the thermal spray parameters rather than by using the trial and error methods that are often used at present.