Ethylene-butyl acrylate formulation

Hermansson et al. carried out extensive investigations on the fire-retardant behavior of ethylene-acrylate copolymer modified with chalk and silicone elastomer.30 32 They have shown that incorporation of a silicone elastomer (at 5wt.%) and chalk filler (at 30wt.%) can greatly improve the flame-retardant properties of ethylene butyl acrylate formulations. The results show that, compared to the pure polymer, an increase in the LOI from 18 to 30, and a decrease in the peak heat release rate (PHRR) from 1300 to 330kW/m2 were observed. 

In a typical formulation, an ethylene-n-butyl-acrylate-carbon monoxide (60/30/10) terpolymer (60 wt%) is melt compounded with plasticized PVC (40 wt%) in a twin-screw extruder and the ethylene terpolymer dispersion cured in situ during the mixing by catalytic amounts of a suitable peroxide (0.3%) and a bismaleimide crosslink promoter (0.2%). The extruded pellets of the elastomeric blend can be used in conventional melt fabrication processes such as profile extrusion, extrusion coating, milling and calendering of sheets, injection and/or compression molding. 

Blends of ethylene copolymers (such as ethylene-vinyl acetate, ethylene-ethyl acrylate, ethylene-acrylic acid copolymers) have been typically added to LDPE, HDPE and LLDPE to improve filler and additive acceptance, balance film properties, improve environmental stress crack resistance, tear resistance, toughness and surface properties. These blends are particularly prevalent in film formulations and as such are rarely disclosed by the manufacturer. Equistar has introduced functionalized polyolefins (Integrate ) to improve dispersion and adhesion in wood fiber filled and mineral filled polyolefin composites. Arkema Group offers Lotryl ethylene-acrylate (methyl, butyl and 2-ethyl hexyl) copolymers and notes the wide range of compatibility with other polyolefins as well as polyamides and polyesters. 

The slurry formulation for tape casting barium titanate sheets consists of the following ingredients barium titanate powder, phosphate ester, methyl ethyl ketone, ethanol, acrylic resin, benzyl butyl phthalate, and poly(ethylene glycol), (a) Explain the function that each of the ingredients has in the formulation, (b) What would be the usual amounts (in wt%) of each of the ingredients in a typical tape cast formulation ... 

Emulsions can be formulated with only hard monomer and plasticized at a later stage, but it is normal to internally plasticize the emulsion by copolymerizing some soft monomer. Vinyl acetate plasticized with an acrylate such as butyl or ethylhexyl acrylate, or a dialkyl maleate, are common combinations. Other hard (high Tg) monomers include methyl methacrylate, styrene, and vinyl chloride. Soft monomers include Vinyl Versatate (Shell Chemicals), ethylene, and vinylidene chloride (Figure 1). 

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