Polyester resins, unsaturated, adhesive

Unsaturated Polyester Resins (UPR). The principal uses are in putty, coatings, and adhesives. Glass-reinforced UPR is used for marine, constmction, and vehicle materials, as weU as for electrical parts. 

Thermosets A number of thermosets have been used as adhesives. Phenolic resins were used as adhesives by Leo Baekeland in the early 1900s. Phenolic resins are still used to bind together thin sheets of wood to make plywood. Urea resins have been used since 1930 as binders for wood chips in the manufacture of particle board. Unsaturated polyester resins are used for body repair and PUs are used to bond polyester cord to rubber in tires, and vinyl film to particle board, and to function as industrial sealants. Epoxy resins are used in the construction of automobiles and aircraft and as a component of plastic cement. 

Polyesters [2] find use in fibers [poly(ethylene terephthalate), poly(ethylene oxybenzoate), poly(ester ethers), poly(ester amides), etc.] [1], coatings (especially unsaturated polyesters) [4], plasticizers, adhesives, polyurethane base resins, films, etc. Cross-linked polyesters prepared from glycerol and phthalic anhydride (alkyd resins) have been reviewed [20], High-melting poly aryl esters have been investigated for high-temperature applications. 

There are basically two types of epoxy acrylate resins used in formulating adhesive systems. One is a vinyl ester resin that is used in two-component adhesive formulations much as a DGEB A epoxy or a polyester resin is. The other is a special type of resin that is used in radiation cure processes. This latter type of epoxy acrylate does not have any free epoxy groups, but reacts through its unsaturation. 

Use Production of polyurethane and unsaturated polyester resins, triethylene glycol textile softener petroleum solvent extraction dehydration of natural gas, plasticizers, and surfactants solvent for nitrocellulose and many dyes and oils humectant for tobacco, casein, synthetic sponges, paper products cork compositions, bookbinding adhesives, dyeing assistant, cosmetics, antifreeze solutions. 

Polyurethane products and formulated systems are used in rigid foams, flexible foams, adhesives, sealants, coatings and elastomers, as well as in many other applications. Propene glycols are used in a wide variety of end-use and industrial applications, from unsaturated polyester resins, cosmetics and household detergents, to paints and automotive brake fluids. Propene glycol ethers are commonly... 

Such compounds - although as a functional group, they also have C=C-double bonds - are not assigned to the acrylate adhesives. These products are mentioned, because experience shows that repairs ofboats, vehicle bodywork (e.g., caravans) and other plastic parts are frequently carried out, where unsaturated polyester resins as two-component systems with hardener component on styrene basis play an important role. 

Polyester resins (alkyds) were commercialized for coatings use in 1926, and unsaturated polyesters were used as thermoset fiberglass composite matrix resins in the 1940s, but the early resins made poor adhesives. When flexibilized resins appeared in the 1950s, they were used as adhesives. Today, unsaturated polyesters are widely used as adhesives for thermoset plastics bonding, and even for metal bonding in most countries, but are seldom used as adhesives in the United States, where the more expensive epoxy adhesives are used in similar applications. The saturated polyesters, used as thermoplastic hot-melt adhesives, seem to have appeared in the literature first in the 1954—1957 period. 

Although unsaturated polyester resins are often regarded as casting plastics in at least one important use, glass-fiber lamination, they are used as adhesives. The method of binding glass-fiber mats with unsaturated polyesters started in 1942 by U.S. Rubber [1]. 

One of the main uses of polyester resin is to function as the adhesive for glass-fiber lamination. The cross-linking reaction of unsaturated polyesters is exothermic that is, it is accompanied by a rise in temperature. Indeed, one of the useful features of an inorganic adherend functioning also as a reinforcing agent in these resins is that the heat of reaction... 

Figure 2.9 Left Good adhesion between fibres and resin is demonstrated by the residual resin on the fibre surfaces after fracture. The specimen was a carbon fibre reinforced PEEK (polyester ether ketone) material. Right Exposure to hot water has caused some loss of adhesion between the glass fibres and the unsaturated polyester resin, as shown by the smooth regions of the fibre where little resin adheres after fracture...

Let us consider the properties of an adhesive based on the following mixture of oligomers an unsaturated polyester resin and a prepolymer with end isocyanate groups (or macrodiisocyanate) based on polydiethylene glycol adipate of molecular weight 800 and on TDI (a mixture of the 2,4- and 2,6-isomers in ratio of 65 35), with the... 

The Sprut-5M adhesive consists of unsaturated polyester resin 100 parts hy weight, ATG-M 80 parts (a mixture of 50 parts of macrodiisocyanate md 30 parts of ATG), polymerization initiator (MEKP(O)) 2 parts. Usually lwt% of CN is integrated additionally into the adhesive base. Sprut-5M can be produced using various polyester resins, but the most applicable one is the adhesive based on PM-I resin owing to its availability and low cost. For this reason we will consider the properties of the adhesive based mainly on this resin although it has adhesion strength 20—40% lower than that of adhesives based on PN-11, NPS 609-21M, and other resins, especially when cementing in water. 

A more convenient method is not to decrease the elastic modulus of the whole adhesive but to form an elastic finish coat [182] not less than 30 pm thick [183] on the adhesive—substrate interface. With lower elastic modulus, the mobility of structural elements decreases. Application of an elastic sublayer decreased the internal stresses during the formation of coatings made of unsaturated polyester resins [185], epoxides [186], and polymer solutions [187]. The use of elastic finish coats found comparatively wide application for paint coatings but seems less promising for adhesive-bonded joints because of decrease of the adhesion strength due to the low cohesion strength of the finish coat itself and because of the labor requirements in producing the adhesive-bonded joints. 

Figure 5.6 shows the dependence of the adhesion strength of steel adhesive-bonded joints on the holding time in hquids. Acrylate (curves 1 and 3) and polyester (curve 2) adhesives were used. In this particular case the polyester adhesive was based on PN 609-2IM unsaturated polyester resin, and the acrylate adhesives were based on MMA (1) and ethyl methacrylate (3). 

NFPA Health 3, Reactivity 2 Uses Catalyst/initiator for vinyl polymehzations and for curing unsaturated polyester resins free radical generator blowing agent for plastics esp. for PVC prod, of floats, buoys polymerization catalyst for paper/paperboard in contact with aq.ffatty foods catalyst in food-contact crosslinked polyesters in food-pkg. adhesives... 

Let us consider a particular ex lmple of the effect of RS substances on the water resistance of adhesive-bonded joints. Adhesives based on unsaturated polyester resins, such as PN-1, are distinguished by low water resistance. The influence of water on a steel joint cemented by such an adhesive actually results in some initial increase of the specific electrical resistance along the adhesive-steel interface and then in an abrupt drop (Fig. 5.5). The increase is explained by more complete consumption of the monomer in the system. When ATG is added to the adhesive (which decreases the interphase tension) the specific electrical resistance stabilizes after a drop. The decrease seems to be related to the processes of relaxation of the internal stresses in the adhesive interlayer. The stresses facilitate the diffusion of liquids in polymeric materials, in particular the stress concentration at the polymer-metal interface. 

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