Polyurethane Vinyl ester resin

The most common advanced composites are made of thermosetting resins, such as epoxy polymers (the most popular singlematrix material), polyesters, vinyl esters, polyurethanes, polyimids, cianamids, bismaleimides, silicones, and melamine. Some of the most widely used thermoplastic polymers are polyvinyl chloride (PVC), PPE (poly[phenylene ether]), polypropylene, PEEK (poly [etheretherketone]), and ABS (acrylonitrile-butadiene-styrene). The precise matrix selected for any given product depends primarily on the physical properties desired for that product. Each type of resin has its own characteristic thermal properties (such as melting point... 

SCRIMP process This Seeman Composites Resin Infusion Process (SCRIMP) is described as a gas-assist resin transfer molding process. As an example glass fiber fabrics/ thermoset vinyl ester polyester plastic and polyurethane foam panels (for insulation) are placed in a segmented tool. A vacuum is pulled with a bag so that a huge amount of plastic can be drawn into the mold (Marco process approach). Its curved roof is made separately and bonded to the box with mechanical and adhesive fastening. It is similar to various reinforced plastics molding processes. 

Although polyurethanes or other reactive resins can be used in RTM, the most common resins are polyesters and epoxies. The two pumping reservoirs in Figure 7.90, then, contain polyester resin and initiator, or epoxy resin and hardener, respectively. Epoxies require relatively long cycle times. When cycle time is critical, low viscosity vinyl ester, acrylamate, or urethanes can be injected very rapidly into the mold. Even the use of thermoplastics is possible. 

For commodity applications, there are four major classes of resins that are used in FRP applications. They are phenolic resin, epoxy resin, unsaturated polyester resin, and epoxy vinyl ester resins. A more complete description of these types of resins and their many variations can be found in Handbook of Thermoset Plastics. This is not a comprehensive list of resins used in composite manufacture, as commodity materials like polyurethanes and isocyanurate resins are sometimes used as well to make FRP parts. However, these materials are not covered in this chapter owing to their limited use, but, the principals of fire safety that apply for the resins described subsequently apply to these materials as well. 

The matrix is considered to be the binder for the microspheres. Typical matrix materials include (a) thermosetting resins such as epoxy resins, unsaturated polyesters, vinyl esters, phenolics, polyurethanes, and silicones (b) thermoplastic resins such as polyethylene, polystyrene, polyvinyl chloride (c) asphalt and (d) gypsiun and cement. 

Thermosetting Resins. Epoxy resin, phenolic resin, unsaturated resin, vinyl ester resin, silicone resin, polyurethane resin and polyisocyanurate resin. 

Dianol . [Akzo] Ethoxylaled bisphenol A diol reactive modifiers for saturatol and unsaturated polyesters, vinyl esters, and polyurethane resin formulations. 

Characteristics of unreinforced resins Unit Epoxy resin Polyurethane resin Vinyl ester resin... 

Journal of Applied Polymer Science 59, No.9, 28th Feb.1996, p.1417-26 POLYMERISATION KINETICS OF POLYURETHANE AND VINYL ESTER RESIN INTERPENETRATING POLYMER NETWORKS BY USING FOURIER TRANSFORM INFRARED SPECTROSCOPY... 

The major thermosetting plastics, in order of decreasing market volume, are polyurethanes, phenol-formaldehyde, urea-formaldehyde, and polyesters. More specialized thermosets include melamine-formaldehyde, furans, vinyl esters, aUyls, epoxy resins, silicones, and polyimides. While they may sometimes compete with each other and with thermoplastics, for the most part, each of them has unique properties and fills unique markets and applications. 

A variation of RIM is reinforced reaction injection molding (RRIM). RRIM refers to a molding process in which the resin is pumped into a closed mold that has been preloaded with dry reinforcements. Polyester resins are often used, but polyurethanes, vinyl esters, and epoxies can be molded via RIM. The advantages of RIM over other reinforced plastic molding processes are ... 

Acid atmospheres. Some industrial or marine atmospheres may also have an abnormally high acidity. Under these conditions phenolics, epoxy ester, chlorinated rubber, chlorinated vinyl, epoxy polyurethane, and tar-epoxy resin paints are recommended. 

Polymerization kinetics of polyurethane and vinyl ester resin SINs were studied [141] by using FT-IR spectroscopy in a temperature range from 60 up to 110 °C. A decrease in the characteristic absorption peaks at 2274 cm corresponding to the isocyanate group, styrene at 910 cm and vinyl ester (VER) at 812 cm was observed (Fig. 14) as the reaction of PU/VER proceeded. 

For the steel sector, two-component cross-linking polymerization adhesives of polyester, vinyl ester, or acrylate base are important. They are relatively tolerant when it comes to the mixing ratio of resin and hardener and can also be used at low temperatures. They are the most important representatives of polyaddition adhesives including 2-part epoxy and 2-part polyurethane adhesives. 

On the other hand, to achieve particular performance, dispersions of several polymers (vinyl acetate, acrylic ester) and resins (hydrocarbon resin, rosin esters) can be added. Special attention must be paid to the compatibility with the polyurethane to avoid dispersion collapse. In general, fillers are not added to waterborne polyurethane adhesives. 

Pentaerythritol in rosin ester form is used in hot-melt adhesive formulations, especially ethylene—vinyl acetate (EVA) copolymers, as a tackifier. Polyethers of pentaerythritol or trim ethyl ol eth an e are also used in EVA and polyurethane adhesives, which exhibit excellent bond strength and water resistance. The adhesives maybe available as EVA melts or dispersions (90,91) or as thixotropic, one-package, curable polyurethanes (92). Pentaerythritol spko ortho esters have been used in epoxy resin adhesives (93). The EVA adhesives are especially suitable for cellulose (paper, etc) bonding. 

The wide variety of applications of anaerobic adhesives and sealants is made possible by the modifications that make the viscosity appropriate to the application. An application that requires penetration into close-fitting parts should have very low viscosity, while a produet used with large, loose-fitting parts should have a high viscosity. A styrene aerylate eopolymer could be used to increase the viscosity [59]. Polymethacrylates, eellulose esters, butadiene-styrene eopolymers, acrylonitrile-butadiene-styrene copolymers, poly(vinyl ehloride), copolymers of vinyl chloride and vinyl acetate, poly(vinyl aeetate), eellulose ethers, polyesters, polyurethanes, and other thermoplastic resins have also been used to eontrol the flow eharacteristics of anaerobic sealants [60]. The flow eharaeteristies of anaerobic formulations can also be controlled by the addition of fumed siliea and other solid additives whieh can impart thixotropic properties [61]. 

---