Ethylene Ethyl Acrylate Copolymer Research Articles

Effect of Ethylene-Ethyl Acrylate Copolymer on the Rheological Properties of LDPE/PLST Blends

The rheological properties of polyethylene/starch blends compatibilized with ethylene–ethyl acrylate copolymer (EEA) were investigated at different temperatures and shear rates. According to the Fourier transform infrared spectroscopy (FT-IR) data, the application of EEA as a compatibilizer did not lead to the significant change in the blends’ band spectra because the concentration of acrylate groups (and consequently that of carbonyl groups) in the blends was low and the degree of hydrogen bonding was small enough. The rheological properties of blends showed that the melts of the blends were pseudoplastic materials. Viscosity of melt for all blends increased with an increase in both EEA and starch content. Power law index measurements showed that the n value increased and was less than one and the K value decreased with the increase in EEA content. Blends with higher content of starch had the lowest value of activation energy (Ea) and the sensitivity of blends to temperature decreased with an increase in starch content.

Influence of different compatibilizers on the morphology and properties of PA6/PET/glass fiber composites

ABSTRACTThree kinds of compatibilizers, ethylene–ethyl acrylate copolymer (EEA), ethylene–ethyl acrylate–glycidyl methacrylate copolymer (EAG), and ethene–maleic anhydride–glycidyl methacrylate copolymer (EMG), were introduced to PA6/PET/GF blends for the first time to study the effect of different compatibilizers on composite. EEA, EAG, and EMG showed different effect on the properties of PA6/PET/GF blends. An observation of the GF–resin interface by scanning electronic microscope indicated EAG and EMG enhanced the adhesion of resin to GF, while EEA exhibited no improvement. Differential scanning calorimetry analysis showed that both EMG and EAG increased the degree of crystallinity of the PA6/PET/GF blends, whereas EEA declined. According to dynamic mechanical analysis, EAG, and EMG remarkably increased the storage modulus of composites. For the composites at a given GF content of 30 wt %, EMG increased the tensile strength from 140.6 to 156.3 MPa. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46429.

Ethylene–ethyl acrylate copolymers via ADMET polymerization: Effect of sequence distribution on thermal properties

ABSTRACTCopolymers of ethylene and ethyl acrylate have been widely used as commodity materials in many fields. In this article, a general synthetic strategy toward fine tuning the ethyl acrylate content and facile control over the monomer sequence regularity of this important type of copolymer via acyclic diene metathesis (ADMET) polymerization followed by hydrogenation is demonstrated. Three structurally symmetric diene monomers (M1–M3) were synthesized in good yields via a three‐step synthetic approach; each of the monomers contains two tail‐to‐tail linked ethyl acrylate units connected to the terminal alkenes by a methylene spacer with specific length. ADMET homopolymerization of M1–M3 and copolymerization of these monomers with 1,9‐decadiene were conducted, and after hydrogenation, a family of periodic and random copolymers of ethylene and ethyl acrylate were obtained. All the polymer samples were characterized by gel permeation chromatography and nuclear magnetic resonance, and the thermal properties of the saturated copolymers were investigated with thermal gravimetric analysis and differential scanning calorimetry. The glass transition and melting behaviors of this family of ethylene and ethyl acrylate copolymers were found to be dependent on the ethyl acrylate content and the primary structure regularity in copolymers. Copolymers with low ethyl acrylate content and periodic microstructures exhibited better crystallinity. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2900–2909

Influence of the Structure of Acrylate Groups on the Flame Retardant Behavior of Ethylene Acrylate Copolymers Modified with Chalk and Silicone Elastomer

This study treats the flame retardant effects of different ethylene acrylate copolymers used in a chalk and silicone elastomer system, specifically the flame retardant chemistry and behavior at lower temperatures. The presence or absence of ester pyrolysis, formation of ionomers or other crosslinks, viscosity, and the effects of these factors on the formation and stability of the intumescent structure formed during heating are discussed. The effects of the acrylate content and melt flow rate in flame retardant compounds based on ethylene butyl acrylate copolymer and ethylene ethyl acrylate copolymer are examined. Results of oxygen index, cone calorimetry (including visual observations), dripping, viscosity measurement, thermogravimetric analysis, and infrared spectroscopy are reported.

Effect of crosslinking on the positive temperature coefficient stability of carbon black‐filled HDPE/ethylene‐ethylacrylate copolymer blend system

AbstractCarbon black‐filled high‐density polyethylene (HDPE)/ethylene ethylacrylate copolymer (EEA) blends were prepared and the effect of crosslinking of the blends on the positive temperature coefficient (PTC) stability was investigated. By irradiation and silane‐crosslinking methods, crosslinked composites with various degrees of crosslinking were obtained. Crosslinking of the matrix polymer led to the disappearance of the negative temperature coefficient (NTC) phenomenon. Also, the PTC intensity increased with an increasing degree of crosslinking. The PTC stability of silane‐crosslinked samples was notably improved at heat cycles of 140°C. This was sufficiently improved by both the silane‐ and radiation‐crosslinking methods when they were treated at 85°C. Therefore, the limiting temperature of self‐regulating heat is about 85°C. Both radiation‐ and silane‐crosslinked samples are thought to be of use to the industry.

Effect of incorporating ethylene‐ethylacrylate copolymer on the positive temperature coefficient characteristics of carbon black filled HDPE systems

AbstractIn order to study the effect of introducing ethylene‐ethylacrylate copolymer (EEA) in carbon black‐HDPE composite systems, two HDPE‐EEA composites prepared by pre‐blending and masterbatch‐blending processes were compared with HDPE and EEA composites in terms of positive temperature coefficient (PTC) characteristics and percolation threshold. The percolation threshold of masterbatch‐blended composites occurred at the lowest carbon black concentration among four kinds of composites. The conduction path in the masterbatch‐blended composite is effectively formed as a result of the localization of carbon black distribution predominantly in the EEA phase, resulting in an increase of conductivity. Ipeak values, the resistivity ratio of the peak to 25°C, of two blend composites were lower than those of HDPE composites. The I85 values, the resistivity ratio of 85°C to 25°C, of masterbatch‐blended composites were higher than those of pre‐blended as well as HDPE composites. It is evident that since most carbon black is dispersed in the EEA phase of the masterbatch‐blended composites, the conduction networks are mainly broken by the crystal melting of EEA before the temperature reaches the crystal melting temperature of HDPE.

Reactive compatibilization of aliphatic polyamides with functionalized polyethylenes

The grafting efficiency on different nylons (6, 11, 12, 6,10 and 6,12) of ethylene-glycidyl methacrylate copolymer (PE- g-GMA) and ethylene-ethyl acrylate copolymer at a composition of 85/15, when meltmixed under optimum conditions, was investigated. Two of these nylons, 6 and 11, were selected to be studied in the complete composition range. Using techniques like dynamic mechanical analysis, tensile testing, differential scanning calorimetry, scanning electron microscopy and Fourier transform infra-red spectroscopy ( FTi.r.) for the characterization of the blends, it was shown that the most efficient grafting occurred in the case of nylon 11/PE- g-GMA blends. The formation of a copolymer was confirmed by extraction experiments. The existence of both polymers in the isolated copolymers was proved by FTi.r. and thermal analysis. Overall, the concept of the compatibilization of the polyamide-polyethylene system was confirmed in the case of nylon 11/HDPE compatibilized by PE- g-GMA copolymer.kw]nylons; ethylene/glycidyl methacrylate copolymers; blends

A comparison of the thermal degradation behaviour of ethylene-ethyl acrylate copolymer, low density polyethylene and poly(ethyl acrylate)

The thermal stability of low density polyethylene (LDPE), poly(ethyl acrylate) (PEA) and ethylene-ethyl acrylate (EEA) copolymer has been investigated in an inert atmosphere using thermogravimetry-differential thermogravimetry (TG-DTG) and under vacuum by thermal volatilisation analysis (TVA). EEA copolymer was also investigated in nitrogen by differential scanning calorimetry (DSC), and LDPE and EEA copolymer have also been examined in air using TG-DTG. The condensable volatile degradation products from TVA experiments were separated by subambient TVA (SATVA) and investigated by FT-IR spectroscopy, mass spectrometry (MS) and GC-MS techniques. The cold ring fraction was investigated by FT-IR spectroscopy and GC. Most degradation products from EEA copolymer were similar to degradation products from LDPE or PEA, while others were new. Mechanisms of formation of the degradation products have been disucssed in detail. EEA copolymer is more stable than PEA but less stable than LDPE in an inert atmosphere, while in air it is more stable than LDPE.

Thermal analysis of blends of low density polyethylene, poly(ethyl acrylate) and ethylene ethyl acrylate copolymer with polydimethylsiloxane

The thermal stability of blends of polyethylene, poly(ethyl acrylate) and ethylene ethyl acrylate (EEA) copolymer with polydimethylsiloxane has been investigated in inert atmosphere using TG-DTC and TVA. The condensable volatile degradation products from the TVA experiments were separated by subambient TVA and investigated by FT-IR spectroscopy, GC., MS and GCMS techniques. The cold ring fraction was characterised by FT-IR spectroscopy and GC. Most of the degradation products from the blends were similar to the degradation products from polydimethylsiloxane and the corresponding polyolefin when degraded alone, but the presence of some additional products indicated interactions during degradation as a result of blending. The mechanisms of formation of degradation products from the blends are discussed in detail.

Thermal analysis and degradation mechanisms of blends of low density polyethylene, poly(ethyl acrylate) and ethylene ethyl acrylate copolymer with calcium carbonate

The thermal stability of blends of low density polyethylene (LDPE) and poly(ethyl acrylate) (PEA) with whiting type coated calcium carbonate of mean particle size 1·5 μ has been investigated in inert atmosphere using TG-DTG and TVA. Ethylene ethyl acrylate (EEA) copolymer has been investigated with different types of calcium carbonate by the same techniques and also by DSC. The condensable volatile degradation products from TVA experiments were separated by subambient TVA (SATVA) and investigated by FT-IR spectroscopy, MS and GC-MS techniques. The cold ring (tar/wax) fraction was investigated by FT-IR spectroscopy and GC. Degradation products from blends of these materials with calcium carbonate were mainly similar to those when the filler was absent but the proportion of cold ring fraction was increased. In the case of EEA copolymer, minor volatile products such as acetic and propanoic acid normally present were either formed in trace amounts or absent when the copolymer was blended with calcium carbonate. Mechanisms of formation of degradation products from the blends are discussed.

Thermal degradation of blends of ethylene-ethyl acrylate copolymer with some inorganic fillers

The thermal stability of blends of ethylene-ethyl acrylate (EEA) copolymer with Al(OH) 3, Mg(OH) 2, MgO and TiO 2 has been investigated in an inert atmosphere using thermogravimetry-differential thermogravimetry TG-DTG, and under vacuum using thermal volatilisation analysis (TVA). The condensable volatile degradation products from the TVA experiments were separated by subambient TVA and investigated by IR spectroscopy, GC, MS and GC-MS techniques. The cold ring fraction was characterised by IR spectroscopy and GC. The degradation products from EEA copolymer with each of these types of filler were mainly similar to the degradation products from the copolymer degraded alone, except that acids such as acetic acid and propanoic acid either were present in trace amounts or were not present. In the case of the blend with TiO 2, however, the amount of acids was greater and that of carbon dioxide was reduced. The filler Mg(OH) 2 was found to prevent the formation of ethylene. The mechanisms of formation of degradation products from blends are altered in the presence of the fillers and are discussed in detail.

Analysis of the Coated Interface Using Fourier Transform Infrared Microspectroscopy

Fourier transform infrared microspectroscopy was applied in order to analyze the interaction of the coated interface between two different polymers. The samples investigated were prepared by coating urethane paint on an ethylene-acrylic acid copolymer (EAA) and on an ethylene-ethyl acrylate copolymer whose ethylester group had been partially hydrolyzed (EAA/EEA). It was demonstrated that a mixed phase was formed along the coated interface between the urethane paint and the EAA and between the paint and the EAA/EEA. The interaction between molecules of the polyurethane and the EAA was observed.

A Novel Second‐Generation Polyolefin Container for Storage of Single‐Donor Apheresis Platelets

A non-blow-molded LE-2 polyolefin (PO) container was developed to store single-donor apheresis platelet concentrates (PCs) processed by the Haemonetics Plasma Collecting System (PCS) at 22 degrees C for over 1 day. We molded PO containers with heat-sealing of light-weight polymer alloy films with a thickness of 0.25 mm. The film was made of polymer blends consisting of polypropylene, styrene ethylene butylene styrene-block copolymer, and ethylene ethylacrylate copolymer. The PO container with enough strength and flexibility in routine practice has 2 and 1.6 times higher oxygen and carbon dioxide gas transfer properties than standard polyvinyl chloride (PVC) plastic containers. PCs (1-1.9 x 10(11) platelets) processed from 450 ml platelet-rich plasma were stored in 0.6-liter PO containers at 22 degrees C with flatbed agitation for up to 6 days. The pH of PCs was well maintained at the mean values of 7.0 in PO containers after 6 days in the well-oxygenated condition. The energy metabolism of stored platelets was determined. Oxygen consumption rates of platelets stored in PO containers averaged 1.5 nmol/min/10(9) platelets. The rates of glucose consumption and lactate production were 0.4 and 0.8 nmol/min/10(11) platelets, respectively. The rates of adenosine triphosphate (ATP) generation of platelets, 9.7 nmol/min/10(9) platelets, in PO containers did not differ from those in the PVC containers. Aggregation responses to adenosine diphosphate and hypotonic shock response of platelets were better maintained in PO containers. The morphological changes into sphere forms with projections and the appearance of unclassified forms were more frequently observed in PO than in PVC containers.(ABSTRACT TRUNCATED AT 250 WORDS)

Photolysis and photo-oxidation of ethylene-ethyl acrylate copolymers

Analytical and kinetic aspects of the photolysis and photo-oxidation of two ethylene-ethyl acrylate (EEA) copolymer samples (15 and 18 wt% EA) are described. On exposure to 254 nm radiation, the absorbing ester groups are mainly split off through Norrish I photo-reactions. Neither ketones nor alcohols are formed during the photolysis at 254 nm. Oxygen favours the disappearance of ester moieties and leads to the formation of carbonyl compounds and alcohols which appear to be hydrogen-bonded to the acrylate groups. On exposure at λ > 300 nm, the EEA copolymers appear to be more photo-oxidisable than EVA copolymers. In EEA, radical attack occurs preferentially on the carbon atom in the α position with respect to the ester groups, whereas the α position with respect to the acetate group in EVA is not an important site of attack.

The radiation crosslinking of ethylene copolymers

The enhanced radiation crosslinking tendency of ethylene-vinyl acetate and ethylene-ethyl acrylate copolymers over ethylene homopolymer is proportional to the comonomer content. This is caused by an increase in the amorphous polymer content and by structure-related factors. The copolymers crosslink by a random process that for ethylene-vinyl acetate copolymer involves some crosslinking through the acetoxy group of the comonomer. While knowledge of the process for the crosslinking of ethylene-ethyl acrylate copolymer is less certain, it is currently believed to occur primarily at the branch point on the polymer backbone. Data relating comonomer content and the molecular weight of the copolymers to the radiation crosslinking levels realized were developed to aid in resin selection by the formulator. Triallyl cyanurate cure accelerator was found to be less effective in ethylene-vinyl acetate copolymer than in homopolymer and to have no effect on gel development in ethylene-ethyl acrylate copolymer.

Alternating ethylene–alkyl acrylate copolymers. I. polymer preparation

AbstractHigh molecular weight alternating ethylene–ethyl acrylate copolymers were prepared by using boron trifluoride to complex the acrylate ester. The polymerizations were run under mild conditions (25–50°C, 6–20 atm ethylene) in dichloromethane or dichloroethane solution with free‐radical initiation. At lower ethylene pressures or at less than stoichiometric levels of BF3, the polymers are acrylate‐rich. This is due to ethyl acrylate homopolymerization competing with the copolymerization reaction. The effect of other polymerization variables is also discussed.

Alternating ethylene–alkyl acrylate copolymers. II. Polymer properties

AbstractProperties such as viscosity correlations and spectral data of alternating ethylene–ethyl acrylate copolymers are described. The proton and 13C‐NMR spectra show that there is a considerable amount of tacticity in these polymers. Although the alternating configuration predominates, there is also some random structure present. Terpolymers were prepared with cure‐site monomers, such as 2‐chloroethyl acrylate. The terpolymers were compounded with carbon black and cured to give vulcanizates with excellent properties. The cured products are resistant to oil, water, heat, and oxidation. They also have good low temperature properties (stiffening temperature −31°C, brittleness temperature −50°C), tensile properties (tensile strength 17.2 MPa, elongation at break 250%) and compression sets (25% at 150°C for 70 hr).

Component redistribution in extrusion of polyethylene compounds

Calorimetrically determined integral heats of solution and swelling ratio measurements carried out on extrudates of low-density polyethylene blended with Surlyn ionomer and ethylene–ethyl acrylate copolymer provide independent evidence for the redistribution of components as a result of extrusion. Although this evidence for “migration” supports earlier data for extrusion-triggered molecular redistribution in polyethylene, the present data further suggest that the effect may be due at least in part to the tendency of crystallizable polydisperse polymers to form cohesively weak boundary layers upon cooling from the melt. Thus, molecular redistribution effects may be expected in the processing of polyethylene and related thermoplastics but would not be pronounced in the extrusion of amorphous, narrow molecular weight distribution polymers, e.g., polystyrene.

Mechanical properties of crosslinked polyethylene and crosslinked ethylene–ethyl acrylate copolymers

AbstractStress–strain curves at various temperatures and secant modulus vs. temperature curves were used to investigate the differences that exist between peroxide crosslinked polyethylene, and vulcanized rubber. A series of hypotheses in terms of crosslinking density and crystallinity is advanced to help visualize the differences between crosslinked polyethylene and cured rubber. The same techniques were used to investigate the nature of crosslinked ethylene–ethyl acrylate copolymers. These copolymers, being more flexible than polyethylene, appear similar to “mechanical rubber,” particularly after crosslinking. Recent experiments, however, indicate that profound differences exist. The performance of crosslinked polyethylene and of ethylene copolymers at elevated temperatures depends on crosslinking density, while at lower temperatures it is dominated by polyethylene crystalline morphology. This latter factor makes crosslinked polyethylene at ambient temperature a completely different product from vulcanized rubber. It also means that a crosslinked polyethylene will have lower crosslinking density than most rubber compositions of equivalent room temperature stiffness. A good indication of crosslinking density of crystalline polyolefins may be obtained by measuring mechanical properties such as modulus at elevated temperatures. Use of reactive co‐agents is effective in raising crosslinking density to the point where fairly good elevated temperature properties are obtained without increasing the room temperature rigidity.