Isophthalic acid based resins

A wide choice of base resin is available in FRP piping. Isophthalic resins are perhaps the standard in most types of industry, but the chemical industry is more likely to use bisphenol A resins for their superior corrosion resistance. Such resins are widely used in chlorine plants, but in wet chlorine itself, vinyl ester and modified resins may give better results [25]. Talbot [26] rates modified bisphenol fumarates superior to the standard resins and to vinyl esters, but finds that chlorendic acid-based resins give even better results. A commercial example of this type is Hetron 197. Notwithstanding this recommendation, today s plants frequently use vinyl ester resins. 

Systems based on isophthalic acid often show better water and alkali resistance than those based on phthalic anhydride. This is not thought to be due to inherent differences between the phthalic and isophthalic structures but is ascribed to the fact that isophthalate resins have generally considerably higher viscosities which enable them to be diluted with greater amounts of styrene. It is the additional proportion of styrene which gives the improved water and alkali resistance. 

Unsaturated polyesters are generally very brittle materials. The tensile elongation for most UPRs is in the range of 1 % for dicyclopentadiene (DCPD)-based polyester resin to about 2.5 % for isophthalic acid and propylene glycol resins. This 1 % elongation posts a problem for using DCPD resin in making a... 

Economics The MX Sorbex process has been developed to meet increased demand for purified isophthalic acid (PIA). The growth in demand for PIA is linked to the copolymer requirement for PET bottle resin applications, a market that continues to rapidly expand. The process has become the new industry standard due to its superior environmental safety and lower cost materials of construction. Estimated ISBL costs based on unit production of 50,000 mtpy of m-xylene (US Gulf Coast site in 2003). 

About half of the benzene produced as a chemical feedstock is for styrene production, followed by large fractions for phenol and cyclohexane-based products. As much as half of the toluene produced is converted to benzene, depending on the price and demand differential. The largest use of toluene itself is as a component of gasoline. Much smaller amounts are used as a solvent, or in the manufacture of dinitrotoluene and trinitrotoluene for military applications. Xylenes are also used in gasoline formulations and function as octane improvers like toluene. para-Xylene and o-xylene are the dominant isomers of value as chemical feedstocks, for the production of terephthalic acid (and dimethyl terephthalate) and phthalic anhydride, respectively. Polyester and the synthetic resin markets, in turn, are major consumers of these products. meto-Xylene is oxidized on a much smaller scale to produce isophthalic acid, of value in the polyurethane and Nomex aramid (poly(m-phenylene isophthalamide)) technologies. 

The oxidation of 5-hydroxymethylfurfural is a reaction of particular interest as far as complete oxidation yields 2,5-furan-dicarboxylic acid (FDA), a material which has properties and applications similar to those of both terephthalic and isophthalic acids [1,5]. Other partially oxidized compounds (Scheme 1) are all involved as intermediates for the preparation of surfactants, synthetic materials or resins [6], Among them, another symmefric compoimd of interest is 2,5 furan-dicarboxaldehyde (FDC), used as such as an antifungal or as a precursor to symmefrical diamines and Schiffs bases. 

The oleoresinous, trimellitic anhydride-based alkyd was also obtained commercially it is a 46% oil length safflower oil resin. In addition to the trimellitic anhydride the resin also contains hydrogenated bis-phenol-A and isophthalic acid (5). 

The chemical compositions of the gelcoat and backing resins are the most important factors for the provision of blister resistance. Isophthalic gelcoats are generally superior to orthophthalic ones. Isophthalic acid/neopentyl glycol based gelcoats have even better blister resistance than those based on... 

Waterborne poly(ester amide) resins based on dehydrated castor oil and niger seed oil have been prepared from fatty amides of oils with isophthalic acid, followed by neutralisation with varying percentages of triethylamine. The neutralised polymers were dispersed in water. These water dispersible resins were cured with hexamethoxymethyl melamine in varying proportions at a high temperature. ... 

P(2) Isophthalic acid (IPA) based resins, where the isophthalic acid replaces the phthalic acid anhydride, should be considered when better water resistance, chemical resistance or heat resistance is required. They have superior mechanical properties with the possibility of a slightly higher elonoation at break Hesnite their more rioid stnirtiire hut are more... 

P(l) Phenolic resins should be considered when the overriding emphasis is on performance nnder heat, retention of properties under lire conditions or low emission of toxic fumes (about 10% that of an isophthalic polyester based glass FRP). The attractive characteristics of composites made from phenolic resins are low flammability, low spread of flame and little smoke. The resole phenoUcs allow similar curing to polyesters with the addition of an acid based catalyst or heat. Though cure at room temperature is possible, an elevated temperature post cure above 80°C is required to obtain dimensionally stable materials. The use of acid based catalysts may lead to moulding tool corrosion. 

The economic design of high-quality tanks for storing hypochlorite solutions has been a long-standing problem [75]. Iitanium would be an excellent material of construction, but only at a yery high cost. Rubber-lined carbon steel has been widely used in both horizontal and vertical tanks. Fiber-reinforced polymers are attractive candidates, but results often have been unsatisfactory. Vinylester resins (e.g., Derakane 411) are preferred, and polyester resins also may be satisfactory. Those with high chemical resistance are best, and bisphenol A resins, for example, are preferred to those based on isophthalic acid. 

Another work-horse solid surface resin based on Isophthalic acid and NPG, UV stabilised and stain resistant and preaccelerated to cure at room temperature with MEKP. c. 900-1200 e. 18-21/25... 

DCPD is used as a raw material in the manufacture of the so-called DCPD-based imsaturated polyester (UP) resins, where both high purity grades and resin grades are used. This class of products shows special characteristics compared to standard UP resins based on orthophthalic anhydride, isophthalic acid, etc. and these include ... 

In recent years the availability of several aromatic polycarboxylic acids has been exploited in specialty alkyd resin preparations [57, 58]. For example, trimellitic acid-based alkyds are used in alkyd-melamine enamels and acrylic lacquers [57]. Isophthalic acid can be used alone or in conjunction with trimellitic anhydride or phthalic anhydride [59]. Pyromellitic acid and pyromellitic anhydride have also been suggested as partial replacements for phthalic anhydride in long or short oil alkyds to give more water-resistant (also caustic- and gasoline-resistant) coatings [60]. 

In addition to MA, phthalic anhydride, and ethylene glycol, other common intermediates used for the production of unsaturated polyesters are fumaric acid, isophthalic acid, adipic acid, propylene glycol, diethylene glycol, and dipropylene glycol. Table 12.1 provides a summary of both common and specialty building blocks used in polyesters and contributions made by these intermediates to the properties of the products. Recycled polyethylene terephthalate beverage bottles may one day become an important raw material for unsaturated polyester resin production, providing an alternative for a substantial part of the petroleum-based intermediates. 

Chemical resistant Highly reactive resin, e. g., based on isophthalic acid + neopentyl glycol, cyclical diols ... 

The use of UP resins based on isophthalic acid-neopentyl glycol allows a considerable improvement in weathering resistance. Figure 5.112 [704], [705]. To protect UP molded parts in outdoor applications, these high-quality resins are often used as a protective layer, e.g., gel coat, s. Section 3.7.14.3.1. 

Vinyl ester resins contain fewer ester groups than resins based on glycol fumarate, phthalic acid, or bisphenol. Therefore, VE resins hydrolyze much more slowly, and the molecular mass does not undergo essential changes during hydrolysis, so that the mechanical properties change very little. Vinyl ester resins are therefore considerably more resistant (especially to alkalis) than phthalic acid, isophthalic acid, or bisphenol resins [32]. 

Metton , Telene and Cymateeh , has not been as a conposite, it is a thermosetting material that can be reinforced or filled and become a composite. DCPD has been used as an impact-modifying agent in standard open and closed molded polyester resins, namely isophthalic and orthophthahc acid based systems. 

The diacid mainly used in the production process for poly(ester-imide) based wire enamel is terephthalic acid (or its dimethylester) (6). Resins are known where isophthalic [46] and phthalic acid [47] are used. The large tonnage products all contain the terephthalic unit. The cured films have better thermal and mechanical properties (e.g., a higher hardness), important when the coated wires are processed in high speed winding machines. 

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