Acrylate thermoset

Carboset [B. F. Goodrich]. TM for water-soluble acrylic thermoset and thermoplastic products. 

There are strengths and weaknesses among the various acrylic thermosetting systems. For example, acid epoxies and urethane cross-linked systems produce no volatile byproducts. Cure temperatures differ widely (see Table VIII). These and other factors determine the acceptability of a particular system for a given application and allow the user considerable latitude in choosing an acrylic that best meets his requirements. 

Chem. Descrip. Amorphous hydrophobic fatty acid amide wax Uses Surf, modifier, surf. tens, modifier, slipagenL antiblocking agent for coatings, inks, piastics, thermoset/thermoplastic polyesters and acrylics, thermosetting aikyds and epoxies, thermoplastic PVC food-contact coatings... 

Synonyms Thermoset acrylic Thermosetting acrylic resin Uses Thermosetting resin for general prod, finishing, exterior coil coating Trade Names Containing Setalux 10-1601 Setalux 6100 GR-74 Setalux 6101 GR-70... 

Thermoset acrylic Thermosetting acrylic resin. See Acrylic resin, ther-moset... 

Texicryl 13-002 Texicryl 13-0386 acrylic, thermoset water-ieduclile... 

Casting Acrylic (thermoset), alkyd, epoxy, nylon, phenolic, polyester (thermoset), polyurethane (thermoset), silicone... 

Powder coatings are not necessarily based on epoxy resins the first powder coatings were based on thermoplastic polymers, and polyolefin, vinyl polymer and polyamide coatings are still used. While those based on epoxy resins are very prominent, there are also polyester, polyurethane and acrylic thermosetting types which we will describe here. 

Figure 9.18 Scanning electron micrograph of the two fracture surfaces of a mica-containing acrylic thermoset that has undergone tensile failure. The mica particle appears on both fracture surfaces and is at the locus of failure...

Thermosetting Acrylics. Thermosetting acrylic adhesives are newly developed two-part systems which provide high shear strength to many metals and plastics, as shown in Table 7.26. These acrylics retain their strength to 200°F. They are relatively rigid adhesives with poor peel strength. These adhesives are particularly noted for their weather and moisture resistance as weU as fast cure at room temperature. 

Type of Automotive top coat Thermoplastic Acrylic Thermosetting Acrylic Thermosetting Acrylic NAD... 

In practice, synthetic polymers are sometimes divided into two classes, thermosetting and thermo-plMtic. Those polymers which in their original condition will fiow and can be moulded by heat and pressime, but which in their finished or cured state cannot be re softened or moulded are known as thermo setting (examples phenol formaldehyde or urea formaldehyde polymer). Thermoplastic polymers can be resoftened and remoulded by heat (examples ethylene polymers and polymers of acrylic esters). 

The aerodynamic wheel cover of claim 4, wherein said thermoset adhesives are selected from a group consisting of epoxies, phenolics, isocyanates, cyanoacrylates, acrylics or combinations thereof... 

The thermoplastic or thermoset nature of the resin in the colorant—resin matrix is also important. For thermoplastics, the polymerisation reaction is completed, the materials are processed at or close to their melting points, and scrap may be reground and remolded, eg, polyethylene, propjiene, poly(vinyl chloride), acetal resins (qv), acryhcs, ABS, nylons, ceUulosics, and polystyrene (see Olefin polymers Vinyl polymers Acrylic ester polymers Polyamides Cellulose ESTERS Styrene polymers). In the case of thermoset resins, the chemical reaction is only partially complete when the colorants are added and is concluded when the resin is molded. The result is a nonmeltable cross-linked resin that caimot be reworked, eg, epoxy resins (qv), urea—formaldehyde, melamine—formaldehyde, phenoHcs, and thermoset polyesters (qv) (see Amino resins and plastics Phenolic resins). 

A great variety of resia formulations is possible because other thermosets, such as epoxies or acrylates, and reactive diluents, such as o-diaUyl phthalate [131-17-9] triaUyl cyanurate [101-37-17, or triaUyl isocyanurate [1023-13-6J, can be used to further modify the BT resias. The concept is very flexible because bismaleimide and biscyanate can be blended and copolymerized ia almost every ratio. If bismaleimide is used as a major constituent, then homopolymerization of the excess bismaleimide takes place ia addition to the copolymerization. Catalysts such as ziac octoate or tertiary amines are recommended for cure. BT resias are mainly used ia ptinted circuit and multilayer boards (58). 

In September 1964 the Du Pont company announced materials that had characteristics of both thermoplastics and thermosetting materials. These materials, known as ionomers, are prepared by copolymerising ethylene with a small amount (1-10 % in the basic patent) of an unsaturated carboxylic acid such as acrylic acid using the high-pressure process. Such copolymers are then treated... 

A number of thermosetting acrylic resins for use as surface coatings have appeared during recent years. These are generally complex copolymers and terpolymers such as a styrene-ethyl acrylate-alkoxy methyl acrylamide... 

At low strains there is an elastic region whereas at high strains there is a nonlinear relationship between stress and strain and there is a permanent element to the strain. In the absence of any specific information for a particular plastic, design strains should normally be limited to 1%. Lower values ( 0.5%) are recommended for the more brittle thermoplastics such as acrylic, polystyrene and values of 0.2-0.3% should be used for thermosets. 

Polycarbonate is perhaps the most notoriously notch-sensitive of all thermoplastics, although nylons arc also susceptible to ductileAjrittle transitions in failure behaviour caused by notch sharpening. Other plastics such as acrylic, polystyrene and thermosets are always brittle - whatever the crack condition. 

Sanding is carried out at this stage and, after clean-up, the final colour or top-coat is applied. There is some variation in the resin chemistry used. Alkyds crosslinked with melamine-formaldehyde are widely used for non-metallic pigmentation. Metallics are usually based on acrylics for better durability. The acrylic may be thermoset with melamine-formaldehyde or a thermoplastic lacquer (plasticised copolymer of methyl methacrylate). A thickness of about 50ftm is applied and stoved for 20 min at 130°C (lacquers receive a bake-sand-bake process for a smoother appearance). 

Good quality steel is used and electrozinc is preferred for washing machines. Steel is pretreated with iron phosphate for economy electrozinc with a fine crystal zinc phosphate. No primer is normally used 25-40/im of finish is applied direct to metal. The required properties are best obtained with a thermosetting acrylic or polyester/melamine-formaldehyde finish. Self-reactive acrylics are usually preferred these resins contain about 15 Vo 7V-butoxymethyl acrylamide (CH2=CH —CO —NH —CHj—O —C4H,) monomer and cure in a manner similar to butylated melamine-formaldehyde resins. Resistance or anti-corrosive properties may be upgraded by the inclusion of small amounts of epoxy resin. Application is usually by electrostatic spray application from disc or bell. Shapes are complex enough to require convected hot-air curing. Schedules of 20 min at 150-175°C are... 

Thermoset Plastics Alkyd, amino resin, thermosetting acrylic resin, casein, epoxy, phenolic, polyester, polyamide, silicone. 

Uses. There are about forty to fifty organic peroxides commercially available in more than seventy formulations designed for specific applications which include (1) initiators for vinyl monomer polymerizations, and copolymerizations of monomers such as vinyl chloride, ethylene, styrene, vinyl acetate, acrylics, fluoroolefms and buta-dienestyrene (2) curing agents for thermoset polyesters, styrenated alkyds and oils, silicone rubbers and poly allyl diglycol carbonates ... 

Some polymers like PE and NR get cross-linked on exposure to radiation while others like those based on vinylidene polymers, e.g., polymethylmethacrylate (PMMA), polyisobutylene, degrade. Certain other types of polymer stmctures (high aromatic content or thermoset) resist degradation by high-energy radiation. Coating polymers usually contain acrylic, methacryUc, or fumaric vinyl unsaturation along or attached to the backbone. 

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