Ethylene-co-acrylic Acid Research Articles

Compatibilizing effects for semicrystalline polymer‐infiltrated amorphous polymer matrix: Mechanical (toughness), thermal, and morphological behavior of compatibilized polypropylene/polycarbonate blends

ABSTRACTPolycarbonates (PCs) have been extensively blended with polyolefins such as polypropylene (PP) due to pecuniary advantages. Although the toughness of a pristine PC matrix has been examined, limited works have investigated the toughness of heterogeneous PC/PP blend systems, focusing merely on PC‐dispersed PP matrices. In this study, the mechanical/thermal properties of PP‐dispersed PC matrix (PC‐rich phase) were examined by using potential compatibilizers: poly(maleic anhydride‐alt‐α‐olefin) (OM), ethylene‐co‐acrylic acid (EA), and cyclic olefin copolymer. The incorporation of 0.5–5.0 phr of compatibilizers (OM and EA) into PC substantially enhanced the toughness of PC/PP15 blends according to four different testing methods. The highest toughness was obtained with 0.5 phr of OM and EA. The compatibilized blends displayed enhanced various thermal properties such as glass transition temperatures, heat deflection temperature, and degradation point, due to the compatibilizing effect. Moreover, 0.5 phr of compatibilizers (OM and EA) were determined as the most effective concentration in terms of toughness and most properties, without compromising strengths and moduli. The morphology of PP‐dispersed PC matrix (crystalline polymer‐infiltrated amorphous polymer matrix) differed from that of PC‐dispersed PP matrix. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47684.

Properties of Rubber Seed Shell Flour-Filled Polypropylene Composites: The Effect of Poly(ethylene co-Acrylic Acid)

The effect of adding poly(ethylene co-acrylic acid) (PE-co-AA) in rubber seed shell flour (RSSF)-filled polypropylene (PP) composites on processing, mechanical, water absorption, and morphological properties was studied. The addition of PE-co-AA increased the processing torque in PP/RSSF composites. Furthermore, mechanical properties such as tensile strength, flexural strength impact strength, Young’s modulus, and flexural modulus show significant improvement compared to uncompatibilized composites, while elongation at break is reduced. The scanning electron microscopy (SEM) of tensile fracture specimens revealed that the dispersion of RSSF filler in the matrix improved with PE-co-AA, with fewer agglomerations. Water absorption ability of the compatibilized composites was reduced due to the improved interfacial bonding, which limits the amount of water molecules to be absorbed. PE-co-AA acted as a compatibilizer in PP/RSSF composites. Improvement in the properties of the composites was contributed by homogenization of RSSF particles in the PP matrix and reduction of voids and cracks due to improved interfacial adhesion and bonding between matrix and filler.

Compatibilized polyethylene—thermally reduced graphene nanocomposites: Interfacial interactions and hyperspectral mapping for component distribution

Ethylene-co-acrylic acid (EAA) and ethylene-co-methacrylic acid ionomer (EMAZ) copolymers were used as compatibilizers for polyethylene-graphene nanocomposites generated by melt mixing. At 5 wt% content, the EAA compatibilizer enhanced the tensile modulus of PE by 40 % and shear modulus by >300 % (1 rad/s) due to efficient dispersion of graphene platelets which helped in effective stress transfer. These also resulted in enhanced thermal stability for PE-EAA-G nanocomposite as compared to nanocomposite with EMAZ. The properties of the nanocomposites were significantly better than the conventional nanocomposites based on layered silicate materials. Mapping of the component distribution in the nanocomposites was demonstrated by using hyperspectral imaging. The nanocomposite with EAA exhibited higher extent of spectral signal mixing due to better mixing of filler and compatibilizer in PE matrix. On the other hand, nanocomposite with EMAZ had no spectral mixing as the components did not mix optimally with each other. The DSC thermogram for this nanocomposite also exhibited a small shoulder at low temperature probably due to immiscibility of the compatibilizer with the matrix polymer. The hyperspectral imaging and mapping was thus demonstrated to be a useful method for determination of component distribution in complex nanocomposite systems.

Development and characterization of novel extracellular mimicking blended electrospun scaffolds: effect of scaffold hydrophobicity on endothelial cell growth

Electrospinning has been engaged widely in tissue engineering to make scaffolds that aim to mimic specific physical properties of the extracellular matrix (ECM). Here we focused on forming composite scaffolds from pure or blended ethylene‐co‐acrylic acid (EAA), polycaprolactone (PCL), polyethylene oxide (PEO), chitosan and cellulose acetate (CA). Solvent combinations were optimized to maintain stable electrospinning solutions. Scaffold hydrophobicity is a major regulator of adhesion and infiltration and was measured with goniometry. Scanning electron microscopy was used to determine porosity and fiber dimensions. We hypothesized that endothelial cells would prefer scaffolds that were mildly hydrophilic or hydrophobic and that had fiber characteristics similar to the ECM. The average contact angle for PEO, EAA, CA, EAA‐PCL, PCL and chitosan are 38°, 88°, 95°, 103°, 112° and 117°, respectively. Porosity ranged from ~60 to 90%; fiber width ranged from 10nm‐5μm. Endothelial cell viability was highest on scaffolds that were slightly hydrophobic and had larger widths. Thus, hydrophobicity and fiber characteristics play a crucial role in endothelial cell growth on ECM mimicking scaffolds. Thanks to the NIH.

Synthesis and Morphology of Well-Defined Poly(ethylene-co-acrylic acid) Copolymers

We report the detailed characterization of strictly linear ethylene-co-acrylic acid (EAA) copolymers synthesized via two modes of olefin metathesis polymerization, where control of the polymer microstructure leads to the generation of unique polymer morphologies based on distribution of carboxylic acid moieties along the polymer backbone. Acyclic diene metathesis (ADMET) was used to prepare three high molecular weight, high strength EAA materials bearing pendant carboxylic acid groups along the copolymer backbone precisely placed every 9th, 15th, and 21st carbon, and ring-opening metathesis polymerization (ROMP) was used to create EAA materials of equimolar acid concentrations with irregularly distributed pendant groups along the linear copolymer backbone. Primary structure characterization using FT-IR and NMR techniques are discussed as well as secondary structure analysis via DSC and X-ray scattering. Thermal analysis indicates significant effects of functional group placement on melting temperatures an...

Surface modification of ethylene‐co‐acrylic acid copolymer films: Addition of amide groups by covalently bonded amino acid intermediates

AbstractAmide groups were anchored covalently on the surface of ethylene‐co‐acrylic acid (EAA) copolymer film by surface grafting of amino acid intermediates. The process consisted of four steps: conversion of carboxylic acid groups on the EAA surface to acid chloride groups, amino acid attachment, conversion of amino acid carboxyl groups to acid chloride groups, and amidation. All steps were carried out at room temperature. ATR‐FTIR spectroscopy was used to characterize the film after each step and to measure the kinetics of amino acid attachment. Three amino acids were studied: 12‐aminododecanoic acid (12‐ADDA), 5‐aminophthalic acid (5‐APA), and L‐aspartic acid (AA). The longer‐chain 12‐ADDA compound was selected for its chemical similarity to migratory fatty amides that are commonly used to alter the frictional behavior of polyolefin films. The 5‐APA and AA compounds were selected because each has two carboxylic acid groups that can be converted to amide groups. After amidation, the modified EAA films were characterized by static water contact angle measurements and scanning probe microscopy. Results showed that the 12‐ADDA reacted to the surface much faster than the 5‐APA or AA. Several steps of aggressive rinsing confirmed that the 12‐aminododecanamide was chemically anchored onto the EAA surface. As a result, both hydrophilicity and surface roughness were increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1688–1694, 2004

Compatibilizers for thermotropic liquid crystalline polymer/polyolefin blends prepared by reactive mixing: The effect of processing conditions

AbstractThe effect of processing conditions on the melt formation of a graft‐copolymer compatibilizer for blends of a thermotropic liquid crystalline polymer (TLCP) and polyolefins was investigated. The compatibilizer was formed by a melt acidolysis reaction of a 50/50 (w/w) blend of TLCP and the sodium salt of a poly(ethylene‐coacrylic acid) ionomer. The effects of various processing conditions in a batch mixer and a single‐screw extruder on the extent of reaction were assessed. The extent of graft‐copolymer formation and the efficacy of the product as a compatibilizer for TLCP/polyethylene blends were affected by the processing temperature and the screw (or rotor) speed.

Impact strength and fracture surfaces of interfaces between polyethylene and polypropylene and some ethylene-containing copolymers

The impact strength of annealed interfaces between high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP) and some ethylene-co-vinyl acetate (EVA) and ethylene-co-acrylic acid (EAA) copolymers was obtained using the Notched Izod test. The impact strengths of EVA-HDPE, EVA-LDPE, and EVA-PP interfaces using EVA copolymers with 9 to 27.5 wt % vinyl acetate (VA), and of EAA-PP interfaces using EAA with 3 to 20 wt % acrylic acid (AA), were all equal to or greater than those of the homopolymer used. However, the impact strengths of EAA-HDPE and EAA-LDPE interfaces were all lower than those of pure HDPE or LDPE, with the exception of 3EAA-LDPE. Scanning electron micrographs showed the presence of fibrils and/or voids, mostly on those copolymer-homopolymer fracture surfaces which had high impact strength. X-ray photoelectron spectroscopy of the fracture surfaces showed a greater calculated percentage of AA or VA on both the copolymer and homopolymer sides of the interface than in the bulk for most samples at 15 A penetration. This greater calculated percentage of AA or VA is probably due to chain scission during sample preparation or fracture, which results in additional acid or alcohol groups at the surface that are calculated as increased VA or AA content. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 2221–2235, 1997

Effect of methyl methacrylate-butadiene-styrene copolymer on the thermooxidation and biodegradation of LDPE/plasticized starch blends

The effect of methyl methacrylate-butadiene-styrene copolymer (MBS) on the thermooxidative degradation and biodegradation of low-density polyethylene (LDPE)/plasticized starch (PLST) blends was examined. Ethylene- co-acrylic acid (EAA) was used as compatibilizer and cobalt stearate as pro-oxidant. The thermooxidative degradation was followed by means of Fourier transform infra-red spectroscopy, gravimetric measurements and mechanical properties during incubation of the blends in an air oven at 70 °C. It was found that the oxidation rate increases with increasing amount of EAA and MBS in the blends. The disintegration period also depends on the incubation time. Blends with higher amounts of PLST show a higher rate of biodegradation as monitored during burial in soil. The amount of MBS does not affect the biodegradation of the blends.

Synthesis and near infrared properties of rare earth ionomers

Fully exchanged, anhydrous ionomers of ethylene-co-acrylic acid (EAA) copolymers and ethylene-co-methacrylic acid (EMAA) copolymers containing Dy +3 , Er +3 , Sm +3 , Tb +3 , Tm +3 , and Yb +3 , and mixtures of them, were synthesized and studied in the near infrared region by reflection and Fourier Transform Laser Raman spectroscopies. The EAA copolymers ranged from 1.4 to 8.7 mol % acid and the EMAA copolymers were 7.3 and 16.2 mol % acid. The ionomers were shown to be essentially free of carboxylic acid groups, water, or other forms containing O-H groups and were characterized by infrared and other methods. They are light and heat stable, and become thermoplastic and moldable at ca. 220°C under pressure. When excited at 1.064 μ with a Nd : YAG laser, these ionomers exhibit novel, lanthanide-dependent near infrared luminescence and strong Raman scattering in the near infrared region. The strongest luminescence is observed with Sm +3 ionomers. The Dy +3 ionomer Raman-shifts this source to emit light most strongly in the 1.53-1.55 μ range where the ionomer also transmits light well.

Interfacial Interactions between Polyethylene and Polypropylene and Some Ethylene-Containing Copolymers

Annealed interfaces between high-density polyethylene (HDPE), low-density polyethylene (LDPE), and polypropylene (PP) and some ethylene-co-vinyl acetate (EVA) and ethylene-co-acrylic acid (EAA) copolymers were examined using optical microscopy, scanning electron microscopy (SEM), and electron microprobe analysis. Transcrystalline zones were observed in a polarizing microscope on the copolymer side of the interfaces between EVA copolymers with ≤18 wt % VA or EAA copolymers with ≤6.5 wt % AA and HDPE or LDPE when the samples were heated above the melting points of both polymers and allowed to cool slowly to room temperature. The crystallization temperatures in the transcrystalline zones were all above those of the bulk copolymers and, in some cases, above the melting points of the bulk copolymers. Electron microprobe data on EVA−HDPE freeze-fractured interfaces showed a percentage of VA less than that in the bulk copolymer in the region corresponding to the transcrystalline zone on the copolymer side of the...

Thermal analysis of blends of poly(ethylene co-acrylic acid) (PEA) and epoxidised natural rubber (ENR)

The decomposition behavior of blends of poly(ethylene co-acrylic acid) (PEA) and epoxidised natural rubber (ENR) have been studied by thermogravimetric (TG) and (first) derivative thermogravimetric analysis. The thermograms of ENR show a clear two-stage degradation, whereas that of PEA exhibits three-stage degradation. Surprisingly, in the blends containing 70 and 50% of ENR, multistage degradation is observed, whereas blends containing 30, 20 and 10% ENR exhibit two-stage decomposition with a T 1max (first maximum decomposition temperature) at 430 °C. This higher T 1max in the latter blends indicates the existence of a single phase, owing to strong chemical interactions during melt processing. Activation energy at 10% degradation and half life at 200 °C of the blends have been reported.

SMA polymer thin film electrodeposition on carbon particles

AbstractElectrodeposition of styrene‐co‐maleic anhydride (SMA) polymer, as thin films on carbon particle substrates, was carried out in a fluidized electrode bed reactor (FEBR). Feeder current, time of deposition, flow rate of anolyte (i.e., bed expansion or bed porosity), concentration of SMA in the anolyte, and pH of the anolyte were the key parameters investigated. The film characteristics were evaluated through SEM and FTIR analyses, the amounts determined by weighing. The effect of these parameters on the electrodeposition process is discussed and optimum conditions for deposition are proposed. Also, a possible mechanism for electrodeposition, particularly for the SMA–carbon system, is discussed. Furthermore, where relevant, the parameters and mechanism are compared with those for our parallel work on the ethylene‐co‐acrylic acid (EAA)–carbon system.

Parametric study of EAA polymer thin film deposition on carbon substrates in a fluidized electrode bed reactor

AbstractElectrodeposition of ethylene‐co‐acrylic acid (EAA) polymer, as thin films on carbon particle substrates, was carried out in a fluidized electrode bed reactor. Feeder current, time of deposition, and flow rate of anolyte (i.e., bed expansion or bed porosity) were the key parameters investigated. The film characteristics were evaluated through SEM and FTIR analyses and the amounts determined by weighing. The effect of these parameters on the electrodeposition process is discussed, and optimum conditions for deposition are proposed. Also, a possible mechanism for electrodeposition, particularly for the EAA–carbon system, is discussed.

Adhesion of an Amylolytic Arthrobacter sp. to Starch-Containing Plastic Films

Cells of the amylolytic bacterium KB-1 (thought to be an Arthrobacter sp.) adhered ( approximately 70%) to the surface of plastic films composed of starch-poly (methylacrylate) graft copolymer (starch-PMA), but did not adhere (<10%) to films composed of polymethylacrylate (PMA), polyethylene (PE), carboxymethyl cellulose, or a mixture of PE plus poly (ethylene-coacrylic acid) (EAA), starch plus PE, or starch plus PE and EAA. About 30% of the cells adhered to gelatinized insoluble starch. Dithiothreitol (5 mM), EDTA (5 mM), and soluble starch (1%, wt/vol) had little effect on the adhesion of KB-1 cells to starch-PMA films. However, glutaraldehyde-fixed cells, azide-treated cells, and heat-killed cells did not bind to starch-PMA plastic, suggesting that the observed adhesion required cell viability. Culture supernatant from 5-day-old KB-1 cultures contained a proteolytic enzyme that inhibited cell adhesion to starch-PMA plastics. Trypsin-treated KB-1 cells also lost their ability to bind to starch-PMA plastic. When washed free of trypsin and suspended in fresh medium, trypsin-treated bacteria were able to recover adhesion activity in the absence, but not in the presence, of the protein synthesis inhibitor chloramphenicol. These results suggested that adhesion of KB-1 to starch-PMA plastic may be mediated by a cell surface protein. Although KB-1 bacteria bound to starch-PMA plastic, they did not appear to degrade starch in these films. Evidence of starch degradation was observed for starch-PE-EAA plastics, where <10% of the bacteria was bound, suggesting that cell adhesion may not be a prerequisite for degradation of some starch-containing plastics.