Thermal Properties of Reinforced Plastics

This chapter reviews information available on the measnrement of thermal properties of polymers, both nnreinforced and reinforced. The consequences of incorporating reinforcing agents in the thermal properties of polymers are reviewed. 

Information on standard methods for the determination of the properties of polymers is reviewed in Table 4.1. General reviews of the determination of thermal properties have been reported by several workers [1-6]. These include application of methods such as dynamic mechanical analysis [5], thermomechanical analysis [5], differential scanning calorimetry [4], thermogravimetric analysis [6], and Fourier transform infrared spectroscopy [4], in addition to those discussed below. 

Thermal properties of a range of polymers are reviewed below, and some of these properties are compared in Table 4.2. 

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The industrial value of furfuryl alcohol is a consequence of its low viscosity, high reactivity, and the outstanding chemical, mechanical, and thermal properties of its polymers, corrosion resistance, nonburning, low smoke emission, and exceUent char formation. The reactivity profile of furfuryl alcohol and resins is such that final curing can take place at ambient temperature with strong acids or at elevated temperature with latent acids. Major markets for furfuryl alcohol resins include the production of cores and molds for casting metals, corrosion-resistant fiber-reinforced plastics (FRPs), binders for refractories and corrosion-resistant cements and mortars. 

Examples of major plastic families Thermoplastic thermal properties are compared to aluminum and steel General properties of thermoplastic General properties of thermoset plastic General properties of reinforced thermoplastic General properties of reinforced thermoset plastic Examples of drying different plastics (courtesy of Spirex Corp.)... 

Mechanical and thermal properties of the ACEC XLIII cured with an acid anhydride (cast profiles) and with PAFOs (a reinforced plastic) are compared with the properties of an epoxynovolak resin cured with the same curing agents (Tables 18 and 19). In addition to the high values of flexural strength at 200 °C, good thermal stability (weight loss of only 1.8% after 500 h at 200 °C) was found. 

The plastics industry is wollastonite s largest single customer, accounting for well over a third of all wollastonite consumption. It is valued as a way of reinforcing plastics, improving the mechanical properties and the thermal and dimensional stability of finished products. 

Chapters 1-4 of the book deal with the mechanical, electrical and thermal properties of a wide range of unreinforced and reinforced engineering plastics. Chapter 5 discusses various miscellaneous properties such as wear, abrasion resistance, frictional hardness properties, surface properties and weathering, and chemical resistance. In addition, this chapter covers a particular property of food packaging plastics, namely their gas barrier properties. 

A new area of development is to incorporate the filler permanently into the polymer matrix, by use of coupling reactions. This can increase impact strength and thermal properties of polyamides and modify the anisotropy of partially crystalline plastics, such as polyamides and polyesters. In polypropylene, bonding with kaolin can also improve scratch resistance, which is a useful benefit for automobile interior applications. Surface modification of fillers such as silica, mica, and wollastonite allows these to penetrate markets that were formerly the province of reinforcements such as carbon black and glass fibre. 

As discussed in Chapter 4, in addition to the mechanical properties, incorporation of reinforcing agents or fillers can affect the thermal properties of plastics, such as heat resistance. 

Thermal properties of thermoplastic starch composites reinforced with pehuen husk showed the potential of this bioliber as an excellent reinforcement for composite materials. TPS composites showed a good interaction between the fibers and the plasticized starch matrix due to the natural affinity between husk and starch in the pehuen seed. TPS/PLA/PV A blend showed partial miscibility or co-continuous phase and TPS/PLA/PV A composites presented also discontinuities at the biofiber-polymeric matrix interface. The incorporation of biofiber improved the thermal stability of the composites, increasing the initial decomposition temperature. The biofiber hinders the out-dififusion of the volatile molecules (e.g., glycerol), retarding the decomposition process of starch composites. On the other hand, the degree of crystallinity of composites decreases when pehuen husk content increases (Castano et al. 2012). 

Y. Seki, M. Sarikanat and M. A. Ezan, Effect of siloxane treatment of jute fabric on the mechanical and thermal properties of jute/HDPE. Journal of Reinforced Plastics and Composites. 31 (15), 1009-1016 (2012). 

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