General Purpose Polyesters

General purpose polyesters are based on phthalic anhydride as the saturated monomer and are the lowest-cost class of resin. These general purpose resins are not normally recommended for use in corrosive service. They are adequate for use with nonoxidizing mineral acids and corrodents that are relatively mild. Tests have indicated that general purpose resins will provide satisfactory service with the following materials up to 125°F (52°C)  

Acetic acid, 10% Acids Fatty acids Oleic acid 

Citric acid Lactic acid, 1% Benzoic acid 

Aluminum sulfate Salts Copper sulfate Boric acid Magnesium sulfate 

Ammonium chloride Ferric chloride Nickel chloride 

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Phenolic asbestos, general-purpose polyester glass, Saran, and CAB are adversely affected by alkalies. And thermoplastics generally show poor resistance to organics. 

Chemical resistance of Saran-bned pipe is superior to extruded Saran in some environments, f Refers to general-purpose polyesters. Special polyesters have superior resistance, particularly in alkaUes. 

In the presence of certain aromatic tertiary amines such as dimethylaniline, benzoyl peroxide will bring about the room temperature cure of general purpose polyester resins. 

These polyesters are primarily copolyesters of propylene glycol with maleic and phthalic acids, dissolved in styrene monomer, and cured by peroxides activators (1, 4, 5). In a typical general-purpose polyester, a 103 excess of propylene glycol is cooked with an equimolar mixture of maleic and phthalic anhydrides for eight or more hours at 150-200°C to produce a viscous liquid polyester of 1000-5000 molecular weight. This is then partially cooled, diluted about 60/40 with styrene monomer, cooled to room temperature, and stored. It is later mixed... 

IRefers to general-purpose polyesters. Special polyesters have superior resistance, particularly in alkalies. 

Plastic concrete produced from general purpose polyester and filled with limestone has limited resistance to acids and alkalis. 

The standard corrosion grade isophthalic polyesters are made with 1 1 molar ratio of isophthalic acid to maleic anhydride or fumaric acid with propylene glycol. In general, the properties of isophthalic polyesters are superior to the lower-cost general purpose polyesters, not only in chemical resistance but also in physical properties. They can be formulated to be fire retardant or to protect against the effects of ultraviolet light. 

Chem. Descrip. Silica in a general purpose polyester resin disp. 

Uses Thixotrope tor general purpose polyester resins for laminating or gel coat applies. 

Cast polyesters. General purpose polyester, when blended with a monomer such as polystyrene and then cured, will produce rigid, rapidly curing transparent castings exhibiting the properties shown in... 

Polyester resins can be grouped broadly into two major categories based on compositions and applications general purpose polyester resin and speciality polyester... 

A fast cure, general purpose polyester excellent for thin laminates. Suitable for hand-lay and spray/projection deposition, c. 400-600cps e. 12-20/21... 

Unaccelerated substantially as above - see differences which follow for general purpose, polyester concrete applications, c 200-250 e 7-8/23... 

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