Glass fibre reinforced polymers polyester

A. M. CunUffe and P. T. Williams, Characterisation of products from the recycling of glass fibre reinforced polyester waste by pyrolysis. Fuel, 82, 2223-2230, (2003). J. H. Harker and J. R. Backhurst, Fuel and Energy, Academic Press London, 1981. A. C. Albertson and S. Karlsson, Polyethylene degradation products, In Agricultural and Synthetic Polymers, ACS Symposium Series 433, J. E. Glass and G. Swift (eds), American Chemical Society, Washington DC, 60-64, 1990. 

P Castaing and L Lemoine, Effects of water absorption and osmotic degradation of long-term behaviour of glass fibre reinforced polyester , Polym Compos... 

Fibre reinforced polymers (FRPs) are composed of a reinforcement material (glass, aramid or carbon fibres) surrounded and retained by a (thermoplastic or thermosetting) polymer matrix (unsaturated polyester, epoxy, vinyl ester, or polyurethane). FRPs were first used in the rehahiUtation of reinforced or pre-stressed concrete, but they have also been widely used in the reinforcement of timber structures. 

Polyesters. Main chain of their macromolecules is characterized by repeated — CO—O— groups. Unsaturated polyester resins are thermosets used mainly for manufacturing glass fibre-reinforced plastics products. The most wide-spread type of thermoplastic polyesters are polymers of an aromatic dicarboxylic acid (mainly terephthalic acid) and an aliphatic diol (e. g. ethyleneglycol or butanediol). The most important representatives of this group are poly(ethylene terephthalate) and poly-(butylene terephthalate). Polyarylate aromatic polyester is a high-temperature thermoplastic of an aromatic dicarboxylic acid (terephthalic acid) and an aromatic diol (bisphenol-A). In the chemical sense, polycarbonate is also a polyester. 

Skrifvars M, Mackin T, Skagemerg B (1998) An application of experimental design to the development of glass fibre reinforced polyester laminates with enhanced mechanical properties , Polym Test, 17(5), 345-356. 

The first reinforced plastics were all based on thermoset polymers. For many years the most popular have been the family of polymers known as thermoset polyesters (6.N. 1 ). These are versatile, inexpensive polymers, used extensively with glass-fibre reinforcement, often in substantial plastic components (such as... 

As a class the polyesters find wide application as fibres, as laminating resins for glass-fibre reinforced cars and boats, in moulding compositions, in surface coatings, as adhesives and as plasticizers for PVC. Elastomeric polyesters may also be prepared. Providing that the molecule is flexible (for example by primarily consisting of a carbon-carbon aliphatic backbone with small substituents on the carbon atoms, does not crystallize or has a very low melting point) then the presence of a few ester links, which increase interchain attraction and reduce rubberiness, is not too adverse on the rubbery properties of the polymer. 

The effect of water absorption on the viscoelastic properties of glass fibre reinforced polyester and polyvinyl ester composites has been investigated using DMA by Fraga et al [ 481. These workers contrasted the water absorption behaviour of the pure, unfilled polymers with composites at two temperatures (40°C and 80°C) and evaluated the relative degree of hydrothermal degradation that occurred. 

The highest mechanical strengths are usually obtained when the fibre is used in fine fabric form but for many purposes the fibres may be used in mat form, particularly glass fibre. The chemical properties of the laminates are largely determined by the nature of the polymer but capillary attraction along the fibre-resin interface can occur when some of these interfaces are exposed at a laminate surface. In such circumstances the resistance of both reinforcement and matrix must be considered when assessing the suitability of a laminate for use in chemical plant. Glass fibres are most commonly used for chemical plant, in conjunction with phenolic resins, and the latter with furane, epoxide and, sometimes, polyester resins. 

Glass fibres dominate this field either as long continuous fibres (several centimetres long), which are hand-laid with the thermoset precursors, e.g., phenolics, epoxy, polyester, styrenics, and finally cured (often called fibre glass reinforcement plastic or polymer (FRP)). With thermoplastic polymers, e.g., PP, short fibres (less than 1 mm) are used. During processing with an extruder, these short fibres orient in the extrusion/draw direction giving anisotropic behaviour (properties perpendicular to the fibre direction are weaker). 

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