ORTHOPHTHALIC POLYESTER

Resins based on phthaHc anhydride are termed orthophthalic polyesters, and resins based on isophthaHc acid are isophthaHc polyesters. The most commonly encountered resins are the orthophthaHc polyesters, because the isophthaHc polyesters, although offering improved mechanical and thermal properties, are higher in cost. Resins based on terephthaHc acid [100-21-0] improve upon the property set of isophthaHc polyesters, but are very uncommon owing to higher cost. 

Orthophthalic polyester (OP) HO2 (P25) is added at 20% (w/w) to OP precursor mixture and is stirred to become homogeneous. The film is deposited onto 27 cm plastic plates using spin-coating at 850 rpm for the aqueous-phase. After 48 h, it is dried in an oven at 60°C for 1 h Photocatalytic degradation of dichloroacetic acid, salicylic acid phenol in aqueous-phase and ethanol in gas-phase [577]... 

The dc electrical resistivity and loss tangent of one unreinforced orthophthalic polyester resin [37] over the temperature range 70-170°C [4] are shown in Fig. 4.3, with the dc electrical resistivity changing very gradually when the temperature is held constant at 150°C for several days. 

P(l) Alkalis can cause severe softening of a matrix. Orthophthalic polyester should not be used with concentrated alkalis. 

Property Orthophthalic polyester Isophthalic polyester BIsphenol-A polyester VInylester Epoxy... 

Some authors have studied the wet aging of four thermoset resins (orthophthalic polyester, isophthalic polyester, vinyl ester and epoxy) and their composites reinforced with glass fibers. In particular, resins and composites were aged for 18 months, under three immersion conditions i.e. 20°C and 50°C in seawater, and 50°C in distilled water. The experimental tensile tests have shown the inflnence on weight changes particularly of the matrix resin and the aging medinm (Davies et al., 2001). 

A generai purpose, preacceierated, low reactive, thixotropic, LSE (ultra-low), DCPD modified orthophthalic polyester suitable for hand-lay and spray/projection lamination. 

A medium cure, low reactivity LSE orthophthalic polyester, c. 500-650cps e. 19-28/21 W-1811/12... 

A high reactivity, low viscosity orthophthalic polyester resin for polymer concrete application. 

A preaccelerated, high reactivity orthophthalic polyester resin for mortar/grouting applications. 

An orthophthalic polyester designed for the casting of large cultured marble components such as bath tubs, c. 2600-3000 e. 9-13/25... 

A preaccelerated, rapid cure, thixotropic orthophthalic polyester for the manufacture of automotive repair filler pastes. 

A preacceierated, thixotropic, rapid gel and cure, orthophthalic polyester specifically designed for anchor bolt fixing, mortar and grouting. 

A specially formulated resin to improve the flexibility of orthophthalic polyesters. ... 

A general-purpose orthophthalate polyester is also produced that is used extensively to manufacture boat hulls. 

The second method is based on the formation of nadic anhydride and a chain extension of the molecules. This reacts via a Diels-Alder reaction. The DCPD is split into two cyclopentadiene molecules which react with maleic anhydride to form nadic anhydride. The nadic anhydride reacts further in a condensation reaction as described for orthophthalic polyesters (see Section 6.2.5.1). 

When this first reaction step is terminated, the dicyclopentadiene maleate formed is esterified, blended and finished in the normal way, as described for orthophthalic polyesters. Inherent to a well managed and controlled process, polycondensation will generate reaction water containing unreacted raw materials and impurities from the used DCPD raw material. These are byproducts with hazardous characteristics and have a very strong smell. The production of DCPD resins, therefore, normally takes place in a closed system and includes treatment of all gaseous and liquid emissions. To treat the off-gases, the following techniques are currently used ... 

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