Fibre-reinforced thermoset plastic

ISO 7370 1983 Glass fibre reinforced thermosetting plastics (GRP) pipes and fittings -Nominal diameters, specified diameters and standard lengths. 

Owolabi, O., Czvikovszky, T., and Kovacs, I. (1985) Coconut fibre reinforced thermosetting plastics, 30, 1827-1836. 

And since most of the plastic composites used in construction are of fibre reinforced thermosets, these will be emphasised in discussions. 

Because of low Mohs hardness. ZnS pigments cause virtually no wear on moulds and do not impair the mechanical strength of fibre-reinforced plastics (in contrast to abrasive pigments such as Ti02). Their main applications are in thermosetting compounds, glass fibre-reinforced thermosets and thermoplastics, and polyolefins. 

The generic thermosets are the epoxies and the polyesters (both widely used as matrix materials for fibre-reinforced polymers) and the formaldehyde-based plastics (widely used for moulding and hard surfacing). Other formaldehyde plastics, which now replace bakelite, are ureaformaldehyde (used for electrical fittings) and melamine-formaldehyde (used for tableware). 

GRP Glass-fibre reinforced plastic based on a thermosetting resin ... 

The mechanical properties of plastics materials may often be considerably enhanced by embedding fibrous materials in the polymer matrix. Whilst such techniques have been applied to thermoplastics the greatest developents have taken place with the thermosetting plastics. The most common reinforcing materials are glass and cotton fibres but many other materials ranging from paper to carbon fibre are used. The fibres normally have moduli of elasticity substantially greater than shown by the resin so that under tensile stress much of the load is borne by the fibre. The modulus of the composite is intermediate to that of the fibre and that of the resin. 

Recycling of glass fibre-reinforced plastics is reviewed, with special emphasis on remelting of thermoplastic composites, mechanical recycling of thermoset composites, depolymerisation and dissolution of thermosets and thermoplastics, closed loop recycling of glass, and the use of glass as a mechanical compatibiliser. 32 refs. 

The polyester resins, reinforced with glass fibre, are the most common thermosetting plastics used for chemical plant. Complex shapes can be easily formed using the techniques developed for working with reinforced plastics. Glass-reinforced plastics are relatively... 

ISO 75-3 2004 Plastics - Determination of temperature of deflection under load - Part 3 High-strength thermosetting laminates and long-fibre-reinforced plastics... 

ISO 10122 1995 Reinforcement materials -Tubular braided sleeves - Basis for a specification ISO 10371 1993 Reinforcement materials - Braided tapes - Basis for a specification ISO 12215-1 2000 Small craft - Hull construction and scantlings - Part 1 Materials Thermosetting resins, glass-fibre reinforcement, reference laminate ISO 15100 2000 Plastics - Reinforcement fibres - Chopped strands - Determination of bulk density... 

Research on the pyrolysis of thermoset plastics is less common than thermoplastic pyrolysis research. Thermosets are most often used in composite materials which contain many different components, mainly fibre reinforcement, fillers and the thermoset or polymer, which is the matrix or continuous phase. There has been interest in the application of the technology of pyrolysis to recycle composite plastics [25, 26]. Product yields of gas, oil/wax and char are complicated and misleading because of the wide variety of formulations used in the production of the composite. For example, a high amount of filler and fibre reinforcement results in a high solid residue and inevitably a reduced gas and oiFwax yield. Similarly, in many cases, the polymeric resin is a mixture of different thermosets and thermoplastics and for real-world samples, the formulation is proprietary information. Table 11.4 shows the product yield for the pyrolysis of polyurethane, polyester, polyamide and polycarbonate in a fluidized-bed pyrolysis reactor [9]. 

The mechanical strength and operating temperature of plastics are low compared with that of metals. The mechanical strength, and other properties, can be modified by the addition of fillers and plasticisers. When reinforced with glass or carbon fibres thermosetting plastics can have a strength equivalent to mild steel, and are used for pressure vessels and pressure piping. Unlike metals, plastics are flammable. Plastics can... 

In this respect, (thermoset) plastics composites with discontinuous fibre products are already mostly used in the car body applications, where polyester/E-glass is predominating (mostly because of polyesters, economy, ease of processability and reasonable mechanical properties provided), followed by use of phenolics (when fire retardance is required, in friction linings and engine compartments), and epoxies. Replacement by carbon or aramid fibre reinforcements can reduce body mass by 40% (compared to steel) and with more added strength, but the cost is unfavourable at the moment, as mentioned previously [12, 13]. 

The fundamentals of reinforced plastics have already been outlined in Chapters 1 and 2. They are basically a combination of two materials. There is a fibre reinforcement (normally glass) which is embedded in a resin. The applications discussed here have historically employed thermosetting resins. The fibre bears most of the mechanical load placed on the structure, while the resin is there essentially to protect the fibre from chemical attack. 

Polymer composites are plastics within which fibres are embedded. The plastic is known as the matrix (resin) and the fibres dispersed witbin it are known as the reinforcement Thermosetting matrix materials include polyester, vinyl ester and epoxy resins. For higher temperature and extreme environments, bismaleimlde, polyimide and phenolic resins are used. Composites can be used to replace metal parts but care must be taken during design. Most engineering materials have similar properties in any direction (called isotropic) where composites have not This can however be offset by arranging the reinforcement layers in varying directions. 

Fibre reinforced plastics. The most wide-spread reinforcement is glass fibre as roving, chopped strand mat, fabric, etc. The most usual matrix materials are unsaturated polyesters and epoxy resins as thermosets. In glass fibre reinforced thermoplastics (e. g. ABS, PA, PPO), the length of the glass fibres is 1 to 3 mm. Other reinforcing fibres are aramide, asbestos, boron, carbon, etc. 

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. 

Natural fibres possess sufficient strength and stiffiiess but are difficult to use in load bearing applications by themselves because of their fibrous structure. Most plastics themselves are not suitable for load bearing applications due to their lack of sufficient strength, stiffness and dimensional stability [51]. In natural fibre reinforced composites, the fibres serve as reinforcement by giving strength and stiffness to the structure while the plastic matrix serve as the adhesive to hold the fibres in place so that suitable structural components can be made. The matrix for the natural fibres includes thermosets, thermoplastics and mbber. Different plant fibres and wood fibres are fotmd to be interesting reinforcements for rubber, thermoplastics and thermosets [52-58]. 

Thus, substrates such as aluminium and its alloys, alloys of titanium, low- and high-carbon steels, nickel, copper, fibre-reinforced plastics (containing both thermoplastic and thermosetting matrices - in the latter case, the matrix might well also be a formnlated epoxy-based system), glass, concrete and wood are all encountered. This means that they can be, and indeed are, widely used in construction, aerospace, automotive (both original equipment and aftermarket), electrical and electronics, furnimre, foundry, consumer and abrasives applications. 

Plastics—Determination of Temperature of Deflection under Load—Part 3 High-Strength Thermosetting Laminates and Long-Fibre Reinforced Plastics... 

The two decades have witnessed an extensive research and development in the field of thermoset nanocomposites. The physics and chemistry of intercalation of clay (layered silicate) in thermoset resin have been understood to a great extent though synthesis of fully exfoliated thermoset-based nanocomposites still remains as a challenge. More research is necessary to study the feasibility of integrating the nanoreinforced thermoset resins into the fibre-reinforced plastics to develop composite structure not... 

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