Ethyl-ethylene copolymers

Figure 5.29. The growth of a wetting layer at the surface of a blend of ethyl-ethyl ethylene copolymers, measured by nuclear reaction analysis. After Steiner et al.

This type of adhesive is generally useful in the temperature range where the material is either leathery or mbbery, ie, between the glass-transition temperature and the melt temperature. Hot-melt adhesives are based on thermoplastic polymers that may be compounded or uncompounded ethylene—vinyl acetate copolymers, paraffin waxes, polypropylene, phenoxy resins, styrene—butadiene copolymers, ethylene—ethyl acrylate copolymers, and low, and low density polypropylene are used in the compounded state polyesters, polyamides, and polyurethanes are used in the mosdy uncompounded state. 

Ethylene-ethyl acrylate copolymers are very similar to the ethylene-vinyl acetate copolymers. The former materials are considered to have higher abrasion resistance and heat resistance whilst the EVA have been considered to be tougher and of greater clarity. 

Specialty waxes include polar waxes for more polar adhesive systems. Examples would be castor wax (triglyceride of 12-hydroxy stearic acid) or Paracin wax N- 2 hydroxy ethyl)-12-hydroxy stearamide) which are used in polyester, polyamide, or with high VA EVA copolymer-based systems. Other common polar waxes are maleated polyethylenes, which are used to improve the specific adhesion of polyethylene-based adhesives, and low molecular weight ethylene copolymers with vinyl acetate or acrylic acid, which are used to improve low temperature adhesion. High melting point isotactic polypropylene wax (7 155°C) and highly refined paraffin wax (7,n 83°C) are used where maximum heat resistance is critical. Needless to say, these specialty waxes also command a premium price, ranging from 2 to 5 times that of conventional paraffin wax. 

The majority of plasticiser consumption is in CR and NBR. Plasticisers are also technically important in chlorosulphonated polyethylene, hydrogenated nitrile, ethyl acrylate copolymer, epichlorohydrin copolymer and ethylene-acrylic terpolymer. At around 10 kt/annum (Europe), total consumption of plasticisers is on a much smaller scale than the process oils used in hydrocarbon rubbers. Typical addition levels are below 20 phr. 

Figure 14.9 Effect of various impact modifiers (25wt%) on the notched Izod impact strength of recycled PET (as moulded and annealed at 150°C for 16 h) E-GMA, glycidyl-methacrylate-functionalized ethylene copolymer E-EA-GMA, ethylene-ethyl acrylate-glycidyl methacrylate (72/20/8) terpolymer E-EA, ethylene-ethyl acrylate EPR, ethylene propylene rubber MA-GPR, maleic anhydride grafted ethylene propylene rubber MBS, poly(methyl methacrylate)-g-poly(butadiene/styrene) BuA-C/S, poly(butyl acrylate-g-poly(methyl methacrylate) core/shell rubber. Data taken from Akkapeddi etal. [26]...

EEA (ethylene-ethyl acrylate copolymer)0 Lotryl EEA Union Carbide... 

Insite technology from Dow Chemical has enabled the production of ethyl ethylene-styrene interpolymers (ESI) by copolymerisation of ethylene and styrene monomers. The properties of interpolymers vary significantly with copolymer styrene content. Interpolymers with up to about 45 wt.% copolymer styrene are semi-crystalline and exhibit good low temperature toughness. Interpolymers with greater than about 45 wt.% copolymer styrene are... 

Propylene Ethylene Oxide Ethylene Dichloride Ethyl Benzene Ethyl Alcholni Acetaldehyde normal alcohols alpha olefins Ethyl Chloride Copolymers... 

Ethylene copolymers with methyl methacrylate and ethyl, butyl, and methyl acrylates are similar to EVA products but have improved thermal stability during extrusion and increased low-temperature flexibility. The commercial products generally contain 15-30% of the acrylate or methacrylate comonomer. Applications include medical packaging, disposable gloves, hose, tubing, gaskets, cable insulation, and squeeze toys. 

Because of their lower level of crystallinity these copolymeis soften at lower temperatures than polyethylene. Table I compares the torsional stiffness at various temperatures of an 18% ethyl acrylate-82 % ethylene copolymer with that of a 21,000 molecular weight, 0.918 density polyethylene made by high pressure polymerization (Bakelite DYNH, Union Carbide Corp.). 

Extraction Studies. Ethylene-ethyl acrylate copolymers were used almost exclusively in the studies reported here because of their commercial availability. All radiation exposures were accomplished with a 2 million volt, 500 watt van de GraaflE electron accelerator. Radiation doses are given in megareps, which is defined as 83.8 X 10° ergs per gram. 

Table II. Extraction of 5 wt.% Ethyl Acrylate-Ethylene Copolymer with Boiling Toluene"...

Properties of Crosslinked Films. Our purpose was to determine which commercially useful property improvements result from radiation crosslinking of ethylene-ethyl acrylate copolymers. Table III illustrates... 

Figure I. Effect of radiation crosslinking on stiffness of 85/15 ethylene-ethyl acrylate copolymer over the temperature range 25°-300°C.

Ethylene—Ethyl Acrylate. Behavior of U.C.C. DQDB 6169 ethylene-ethyl acrylate copolymer was somewhat similar to that of ethylene-vinyl... 

Amphiphilic block copolymers consisting of a hydrophobic (poly(ethyl ethylene) (PEE) and a hydrophilic polyethylene oxide)(PEO) block form monolayers at the air-water interface. The schematic molecular arrangement of this diblock is shown in Fig. 3.26. 

M.B. Maurin, L.W. Dittert, and A.A. Hussain, Thermogravimetric analysis of ethylene-ethyl acetate copolymers with FTIR analysis of the pyrolysis products. Thermochim. Acta, 186, 97-102 (1991). 

McNeill, I.C. and Mohammed, M.H., A comparison of the thermal degradation behaviour of ethylene-ethyl acrylate copolymer, low density polyethylene and poly(ethyl acrylate), Polym. Deg. Stab., 1995,48, 175-187. 

Ethylene Copolymers. Ethylene copolymers probably are the most important materials in hot-melt formulations. Ethylene-vinyl acetate and ethylene-ethyl acrylate polymers are very versatile and available in a wide range of grades offering different co-monomer contents and viscosities. The melts are stable and compatible with various modifying resins, waxes, extenders, and fillers. Adhesion to many substrates is good—including the polyolefin plastics, which are difficult to bond with most other types of adhesive unless the surfaces are pre-treated. 

Bead-Shaped Methylphenyl(Ethyl)Siloxane Copolymers with Ethylene Bridges between Cycles... 

The liquid phase of the dispersions contained, by weight, 99% methyl methacrylate, 0.5% distilled dimethyl-p-toluidine, and 0.5% ultraviolet absorber. Matrices used for volume concentration effects contained 5% ethylene dimethacrylate and 10% methyl methacrylate-ethyl methacrylate copolymer with methyl methacrylate monomer reduced to 84%. Matrices containing 5% additives (described above) contained 15% triethylene glycol dimethacrylate with methyl methacrylate reduced to 79%. 

Ethylene may be copolymerised with vinyl acetate to make ethyl-vinyl acetate, offering high seal integrity and clarity for frozen food applications where a high degree of toughness is required. Ethylene copolymers with other olefins such as propylene, 1-hexene and 1-octene allow a range of properties to be achieved. Linear low density polyethylene (LLDPE) has a... 

In the next step the variation of the solubility parameter 8 is considered due to the change in the microstructure. All three descriptions agree that the parameter 8 of the random copolymer E EEx should decrease monotonically with increasing ethyl ethylene fraction x (see the inset to Fig. 10a). The original Bates formulation are extended beyond isotopic mixture by [136, 143] (but still for nonpolar substance and similar volumes of interacting species (VE-Vee)/V 1.4% 1) emphasizing the role of AV/V alone [136] or correlated Aa/a... 

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