Thermoset polymeric fibres

Compounds are short (/w 0.3 mm) or long (> 0.6 mm) fibre reinforced thermoplastic or thermoset polymeric materials, which are processed automatically (injection or compression moulding), have good (mechanical) properties (for automotive, electric and electronic applications) and are relatively cheap. Composites contain continuous fibres (rovings, fabrics or mats), usually combined with thermosets, have excellent mechanical (structural) properties, but are very expensive because lack of an industrial process (mainly used in aerospace and aircraft industry). 

In composites, particulate inorganic fillers or reinforcing materials such as fibres are commonly added to thermoplastic and thermoset polymeric materials to achieve economy while modifying certain properties such as stiffness, heat distortion and mouldability. However, there are certain properties such as toughness and ultimate elongation that usually deteriorate. 

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 proportion of bio-based materials in each of the sectors of elastomers and fibres accounted for almost 40% due to the use of 290 000 t of natural rubber and 300 000 t of cellulosic fibres. The market size for thermoplastics and thermosets amounted to circa 15.8 million t, of which circa 12.5 million t accounted for rigid materials, mainly in packaging, building and construction, automotive and electronics industries as well as for furniture and consumer goods. A volume of 3.3 million t is attributed to adhesives, paints and lacquers, binders and other polymeric additives. In these areas it is estimated that bio-based materials... 

The term binder is used to mean the matrix in which the fibres are embedded or treated. The binders, sometimes called adhesives or matrixes, in this chapter refer to polymeric materials having reasonable mechanical properties. The binder may be thermosetting or thermoplastic polymers. 

The APC materials typically nsed for on-site rehabilitation of timber and concrete are composed of glass, carbon or aramid fibres and a polyester, epoxy or polynrethane polymeric matrix. Glass fibres are the most frequently used due to their moderate cost and good mechanical properties when compared to carbon fibres. They are used normally in the form of pultruded profiles or strips, fabrics (tissues) or mats. Carbon fibres are mainly used in the form of pultruded profiles of solid, open or hollow cross-sectional shapes. While in timber applications both thermoplastic and thermosetting matrix types are used, in concrete applications only the latter type is used. 

Polymeric materials are used in simple household items like plastic bags as well as in advanced optical or electronic components or in medical applications. The main fields of application for Western Europe are shown in Figure 1.5. which does not include data about elastomers and cellulosic fibres. For 2003, the total amount of consumed thermoplastics and thermosets in Western Europe was 48788 kilotoimes. 

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