Polyester resins film-forming

Dry chlorine has a great affinity for absorbing moisture, and wet chlorine is extremely corrosive, attacking most common materials except HasteUoy C, titanium, and tantalum. These metals are protected from attack by the acids formed by chlorine hydrolysis because of surface oxide films on the metal. Tantalum is the preferred constmction material for service with wet and dry chlorine. Wet chlorine gas is handled under pressure using fiberglass-reinforced plastics. Rubber-lined steel is suitable for wet chlorine gas handling up to 100°C. At low pressures and low temperatures PVC, chlorinated PVC, and reinforced polyester resins are also used. Polytetrafluoroethylene (PTFE), poly(vinyhdene fluoride) (PVDE), and... 

This is a material produced from the impregnation of glass fibre-mat (fibreglass, which is in the form of dry sheet, is commonly known as chopped stranded mat (CSM)) or rovings, with a liquid and unsaturated polyester resin, which thickens chemically to a dry sheet form. The total mix is sandwiched between polyethylene films and then roller-pressed to impregnate and consolidate it. 

Polyesters are eneountered in many forms. They are important as laminating resins, moulding compositions, fibres, films, surface coating resins, rubbers and plasticisers. The common factor in these widely different materials is that they all contain a number of ester linkages in the main chain. (There are also a number of polymers such as poly(vinyl acetate) which contain a number of ester groups in side chains but these are not generally considered within the term polyester resins.)... 

Allyl resins Polyester Moulding Compositions Fibre-forming and Film-forming Polyesters Polyfethylene terephthalate) Moulding Materials... 

Four different polyester plasticisers for PVC, having moderate acid numbers (11.5 to 20.5 mg KOH/g resin), were synthesised. These polyesters were modified by converting the terminal COOH group to Ba(II) and Cd(II) carboxylate salts in order to introduce the capability of heat stabilisation for PVC. The modified polyesters were applied as dual function polyesters, i.e. as plasticisers and stabilisers at the same time. The thermal stabilisation efficiency of the plasticised PVC films formed was tested photometrically and the data obtained were compared with that afforded by Irgastab BZ 556. The efficiencies of these modified polyesters as heat stabilisers for PVC were found to be comparable with those of Irgastab BZ 556. 38 refs. CIBA-GEIGY CO. 

Although linear polyester resins do not readily undergo heat curing, they form extremely flexible paint films with excellent adhesion to metal substrates. Poiyisocyanate resins are more resistant to hydrolysis than amino resins. Polyester-polyurethane paints therefore exhibit improved resistance to moisture and weathering but are more expensive. 

Prepolymers. A broad range of acrylated resins (oligomers) are commercially available. The film-forming properties depend on the oligomer system. One of the most common is the acrylated epoxy system. In acrylated urethanes, an isocyanate-functional prepolymer with a polyol backbone can be reacted with a hydroxy-functional monomer (e.g., hydroxyethyl or hydroxypropyl acrylate). Many different resins can be synthesized by varying the polyol backbone, the isocyanate type, and the hydroxy-functional monomer. Polyester acrylates are another example of commercially important prepolymers. Acrylated acrylics have an acrylic backbone with pendant acrylate functionality. 

Thermosetting polyester resins are used in paints and surface coatings. In these, oxidation during drying forms a cross-linked film, which provides a tough, resistant finish. 

Paint consists of a mixture of pigments which gives body and colour, and a resin or binder which is the actual film-forming component and acts as a glue to hold the pigment together and stick them to the surface. Binders include synthetic resins such as acrylics, polyurethanes, polyesters and epoxies and can be a combination of resins, e.g. epoxy/ acrylic and polyurethane/acrylic. To adjust the curing properties and reduce the viscosity so that the paint can be easily applied, a solvent or carrier is used. These evaporate after application and do not form part of the paint film. In waterborne paints, the carrier is water. With solvent-borne paints, also called oil-based paints, the carrier is a solvent such as acetone, turpentine, naphtha, toluene, xylene and white spirit. 

NFPA Health 0, Flammability 1, Reactivity 0 Uses Comonomer for alkyds and unsat. polyester resins chemical intermediate for paints, in polyester bottle resins, fibers, and films in prod, of terephthalic acid esters forms polyesters with glycols in analytical chemistry reagent for alkali in wool as poultry food additive... 

The vacuum bag is the impermeable film that is generally applied to the outside of the layup to facilitate conformability to the mold form and air removal during cure. Polyvinyl chloride (PVC) bags are useful up to 66°C and are less expensive than polyvinyl alcohol (PVA). Certain PVC polymers, however, inhibit polyester resins and prevent a tack-free cure. When high curing temperatures or steam-autoclave curing is required, the bag should be made of neoprene rubber or some similar elastomer. Film materials suitable for bag manufacture also include cellophane, polypropylene, nylon, and fluorocarbons. Silicone and butyl rubbers are also used to make vacuum bags. To make the best parts, the bag should be tailored to the part so that wrinkles will be at a minimum. 

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