Unsaturated polyester applications

Flame-Retardant Applications. The flame resistance of polyolefins, unsaturated polyester, mbber, and many other synthetic materials can be improved by the iaclusion of chloriaated paraffias. The soHd 70% chlorine product is the preferred choice ia most polymeric systems, but the Hquid grades are widely used ia mbbers, polyurethane, and textile treatments. 

At about the same time, an allyl resin known as CR39 was introdueed in the United States as a low-pressure laminating resin. This was followed in about 1946 with the introduction of unsaturated polyester laminating resins which are today of great importance in the manufaeture of glass-reinforced plasties. Alkyd moulding powders were introduced in 1948 and have since found specialised applications as electrical insulators. 

World production of unsaturated polyester resins in 1997 was of the order of 1.7 X 10 tonnes, with the USA accounting for about 45% and Western Europe 27%. Over 75% is used in reinforced plastics, with the rest being used for such diverse applications as car repair putties, cultured marble , wood substitution and surface coatings. The pattern of consumption in 1993 of reinforced polyesters in the USA was reported as ... 

The applications of the unsaturated polyester resins were increased in the late 1960s by the introduction of water-extended polyesters. In these materials water is dispersed into the resin in very tiny droplets (ca 2-5 p.m diameter). Up to 90% of the system can consist of water but more commonly about equal parts of resin and water are used. The water component has two basic virtues in this system it is very cheap and because of its high specific heat it is a good heat sink for moderating cure exotherms and also giving good heat shielding properties of interest in ablation studies. 

For example, the molecular weight of unsaturated polyesters is controlled to less than 5000 g/mol. The low molecular weight of the unsaturated polyester allows solvation in vinyl monomers such as styrene to produce a low-viscosity resin. Unsaturated polyesters are made with monomers containing carbon-carbon double bonds able to undergo free-radical crosslinking reactions with styrene and other vinyl monomers. Crosslinking the resin by free-radical polymerization produces the mechanical properties needed in various applications. 

For almost all applications unsaturated polyesters are dissolved in an unsaturated monomer capable of free-radical polymerization with the unsaturations in polyester chains. This polymerizable comonomer is generally styrene, but other compounds, such as methyl methacrylate, vinyl toluene, a-methylstyrene, and diallylphthalate, are also used in some applications. Upon heating and in... 

Economic and ecological aspects of chemical recycling are examined, and the application of such processes to the recovery of monomers and intermediates from PETP, polyamides, polyurethanes, polycarbonates, unsaturated polyesters, polyacetals, PMMA and PS is discussed. 17 refs. SNIA... 

Polyester resins. The fire-performance characteristics of unsaturated polyester resins are of utmost importance in many application areas, particularly in the construction, transportation and electronics industries ( 1 3). Consequently, these plastics represent one of the major growth areas for fire retardants in recent years ( 1 4). 

Microgels which have been prepared in emulsions or microemulsion have a more compact structure than those obtained by polymerization in solution. For microemulsion copolymerization, preferentially self-emulsifying comonomers, such as unsaturated polyesters, are used as polymerizable surfactants, because no emulsifier must be removed after the reaction. By choosing suitable monomer combinations the composition, size and structure of microgels can be widely varied, thus adjusting these macromolecules to special applications. 

Polyester polyols, 25 464 468 Polyester resin(s), 11 302 coating resins, 7 104-106 cyclopentadiene and dicyclopentadiene applications, 8 230 flammability of, 20 115-116 properties in powder coating, 7 43t standard test methods for, 20 11 It unreinforced, 10 187t weathering of, 20 116 Polyester resin-based powder coatings, organic titanium compounds in, 25 125 Polyester resin composites, 26 762-763 Polyester resin formulations ingredients of, 20 96t unsaturated, 15 511-512 Polyesters, 10 185-189, 497 12 655-656. See also Thermoplastic polyesters Unsaturated polyesters acid resistance of, 20 7-8 antioxidant applications, 3 121 aromatic ionic, 23 722 based on 1,4-cyclohexanedimethanol, 12 674-675... 

Osaka Organic Chemical will embark on volume production of a low-toxicity acrylic ester monomer with extremely low skin irritation, it is briefly reported. Principal applications are as a diluent monomer for UV and EB coating materials and inks, and as a modifier in unsaturated polyester resins, acrylic resins and PVC. OSAKA ORGANIC CHEMICAL INDUSTRIES CO.LTD. 

P.R.164 was also found in cast resin composed of methacrylate and unsaturated polyester. The pigment does not affect the hardening process of such media, which may be carried out, for instance, by using peroxides. An important field of application was in the coloration of various polyurethanes, for which the pigment was also sold in the form of a pigment preparation. 

One of the primary fields of application for P.R.151 is in polystyrene, although there is a slight color change at temperatures above 260°C, at which the pigment partially dissolves. It is also used to a considerable extent in ABS. Cast resins based on methylmethacrylate and unsaturated polyesters are also frequently colored with P.R.151, which is resistant to the peroxide catalysts that are used to harden the plastic. The lightfastness in these media is good it equals step 6-7 on the Blue Scale. 

P.Y.110 lends color to polystyrene and styrene containing plastics. It is a suitable candidate for unsaturated polyester and other cast resins, as well as for polyurethane. P.Y.110 is used to an appreciable extent in polypropylene spin dyeing, it is very lightfast in this medium. It is utilized in polyacrylonitrile spin dyeing and sometimes also in polyamide. Its fastness properties, however, especially its lightfastness, do not meet special application conditions (Sec. 1.8.3.8). 

P.B.15 3, like stabilized a-Copper Phthalocyanine Blue, markedly affects the hardening of unsaturated polyester cast resins. The list of applications also includes PUR foam materials, office articles, such as colored pencils, wax crayons, and water colors, as well as spin dyeing of polypropylene, polyacrylonitrile, secondary acetate, polyamide, polyester, and viscose. Used in polyester spin dyeing, P.B.15 3 satisfies the thermal requirements of the condensation process (Sec. 1.8.3.8). 1/3 and 1/25 SD samples equal step 7-8 on the Blue Scale for lightfastness. Textile fastnesses, such as stability to wet and dry crocking are perfect. 

Moreover, y-P.V.19 is also found in a variety of other media, such as powder coatings and cast resins. This includes systems based on unsaturated polyester resins whose hardening is not affected by the pigment. The list of application media includes plastics which are processed at very high temperature (such as polycarbonates), in which the pigment is thermally stable up to 320°C. PUR foams and... 

P.R.149 also lends color to cast resins made from materials such as unsaturated polyester or methacrylic acid methylester, which are polymerized with peroxide catalysts. P.R.149 is equally lightfast in these media. In polycarbonate, the pigment tolerates exposure to more than 320°C. This is an asset in view of the fact that polycarbonate shows high melt viscosity and is thus processed at up to 340°C. The list of applications also includes other media, such as PUR foams and elastomers, for which P.R.149 is recommended because of its good heat stability and its coloristic properties. 

As can be deduced from plant purchases, the PRC is still at the formative stage where emphasis is on producing only the most basic petrochemicals. No plants were purchased for producing dibasic acids (phthalic and maleic anhydrides, etc.) and fluro-carbon or tetrafluoro ethylene or some of the advanced engineering plastics like ABS polyacetals, polycarbonates, polyimides or any other unsaturated polyesters. Another important area of low Chinese activity is thermoplastics for space and defense applications. ... 

Finally, glass-reinforced unsaturated polyesters are well known as building materials for boats, yachts and cars and generally termed fibre-glass resin . The preparation, properties and applications of these unsaturated polyesters are summarized in Chapter 21, while the chemistry and properties of a new unsaturated polyester resin for fibre-reinforced composite materials are discussed in Chapter 22. 

Table 21.2 provides a general guide to the effect that chemical constituents can have on unsaturated polyester resin end-use performance. The routes to change an unsaturated polyester resin for a particular application is normally apparent and there can be several pathways available to achieve the desired properties. As the unsaturated polyester resin markets are highly competitive, raw material cost usually reduces the number of available routes available to the formulator. As noted previously, there are three main types or families of unsaturated polyesters, namely general purpose orthophthalic, isophthalic and DCPD resins. However, within each of these families, there are hundreds of variants that incorporate these various chemical constituents in different combinations and permutations to achieve the desired results. 

Since unsaturated polyester resins alone would have insufficient strength for structural application, reinforcements are used to enhance the physical strength of such resins. Typically, tensile strength, impact strength and stiffness are the physical properties of most interest. Reinforcements can be regular particulates, as in glass microspheres, irregular particulates, as in flakes, or fibers. 

---