Modulus of plastics

M = Modulus of elasticity (Young s Modulus) in psi, or modulus of plasticity. 

The plasticizer efficiency of chlorinated paraffins is low as compared with conventional primary plasticizers. This is shown in Figure 3, where the 100% modulus of plasticized PVC increases as dioctyl phthalate is replaced by a commercial chlorinated paraffin (C20 average, 46.0% Cl). 

If flexural strength is directly related to a break load of a board (in this context) placed on supports, flexural modulus is directly related to a deflection of a board, placed on supports, under a certain load. Unlike the flexural strength of composite boards, typically significantly exceeding building code requirements at commonly accepted spans (such as 16 in. on center), flexural modulus of plastic-based composite boards often puts certain restrictions for their installation. 

Effect of talc on flexural strength and modulus of plastics is often higher compared with that of calcium carbonate. For example, polypropylene filled with 58% CaC03 had flex strength and modulus of 4430 270 and 365,000 44,000 psi, respectively, but the same polypropylene filled with 20% CaCOs and 30% talc had flex strength and modulus of 6125 + 100 and 486000 18000 psi, respectively. 

The ASTM gives several examples of compressive strength and modulus of plastics. For polystyrene, for example, compressive strength, determined in six different laboratories, is equal to 15,370+200 psi (within-laboratory measurements) and 15,400 500 psi (between-laboratory measurements), and compressive modulus of elasticity is equal to 563 10 psi (within-laboratory measurements) and 560 100 psi (between-laboratory measurements). 

As for tensile modulus of plastics (Table 8.14), the compressive modulus of composite deck boards (Table 8.15) follows the same trends as the elastic modulus with respect to a sample s degree of crystallinity [6]. 

ASTM D747. Apparent bending modulus of plastics by means of a cantilever beam, 1993. 

Fig. 2 Temperature-dependence of the modulus of elasticity (Young s modulus) of plastics (diagram). As an alternative to this modulus, tension a can also be plotted against constant elongation e or viscosity i), or other properties [2]. MSRe x,d- main softening range of elastomers, thermoplastics, duroplastics, Tgt associated glass transition temperature, Tfi flow point of the amorphous thermoplastic, //////// application range, application range...

Figure 11.74. Effect of the amount of di-(2-ethylhexyl) phthalate on modulus of plasticized silicone mbber. [Data from Hayashida A, Mori S, Tabei E, US Patent 5,804,257.1...

The non-uniformity of the molar mass distribution influences polymer properties and their processing (see Table 4.1.5). The distinguishing feature of commercial polymers is that they have molar masses far in excess of the entanglement molar mass of about 10,000 g/mol. From typical industrial synthesis, a fairly broad distribution of molar mass results. The features of this distributicm have dramatic effects on the processability (viscosity) and properties (miscibility, strength and modulus) of plastics. 

T = thermal stress Ep = elastic modulus of plastic ai = CLTE of material 1 02 = CLTE of material 2 AT= temperature change... 

Modulus is the characterization of a rigid material. The elasticity modulus of plastic products made from pure resin is low, even for polyesters and polyamides with relatively higher elastic moduli, which is only 2.5%-10% of the metal elasticity modulus. The modulus of elasticity of filled plastics always increases with the addition of filler because the filler modulus is much larger than the modulus of polymers. For example, when 40 phr of magnesium sulfate whiskers are added to PVC, the breaking strength of the composite material increases by 62.43% and the modulus of elasticity increases by 52.38%.2o... 

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