Impact strength of poly

Figure 35-13. Temperature dependence of the notched bar impact strength of poly(styrene), PS, and high-impact poly(styrene), HIPS. (After C. B. Bucknall.)...

Table 2. Effect of Skew Striking on Impact Strength of Poly(methyl methacrylate) Sheet ...

Siding. The resin most used for siding is poly(vinyl chloride) homopolymer, compounded with modifiers, stabilizers, and pigments. Modifiers are most often acryhc esters, followed by chlorinated polyethylene or ethylene—vinyl acetate, used at 6—8 phr (parts per hundred resin). The modifier increases the impact strength of the rigid PVC. 

As with poly(ethylene terephthalate) PBT-based copolymers have been introduced to overcome some of the deficiencies of the homopolymer. For example, the rather low notched impact strength of unreinforced grades has been overcome by partial replacement of the terephthalic acid with a longer chain aliphatic dicarboxylic acid. Improved toughness has also been obtained by grafting about 5% of ethylene and vinyl acetate onto the polyester backbone. 

Thermoplastic polymers, such as poly(styrene) may be filled with soft elastomeric particles in order to improve their impact resistance. The elastomer of choice is usually butadiene-styrene, and the presence of common chemical groups in the matrix and the filler leads to improved adhesion between them. In a typical filled system, the presence of elastomeric particles at a level of 50% by volume improves the impact strength of a brittle glassy polymer by a factor of between 5 and 10. 

Figure 14.9 Effect of various impact modifiers (25wt%) on the notched Izod impact strength of recycled PET (as moulded and annealed at 150°C for 16 h) E-GMA, glycidyl-methacrylate-functionalized ethylene copolymer E-EA-GMA, ethylene-ethyl acrylate-glycidyl methacrylate (72/20/8) terpolymer E-EA, ethylene-ethyl acrylate EPR, ethylene propylene rubber MA-GPR, maleic anhydride grafted ethylene propylene rubber MBS, poly(methyl methacrylate)-g-poly(butadiene/styrene) BuA-C/S, poly(butyl acrylate-g-poly(methyl methacrylate) core/shell rubber. Data taken from Akkapeddi etal. [26]...

Polycarbonate is blended with a number of polymers including PET, PBT, acrylonitrile-butadiene-styrene terpolymer (ABS) rubber, and styrene-maleic anhydride (SMA) copolymer. The blends have lower costs compared to polycarbonate and, in addition, show some property improvement. PET and PBT impart better chemical resistance and processability, ABS imparts improved processability, and SMA imparts better retention of properties on aging at high temperature. Poly(phenylene oxide) blended with high-impact polystyrene (HIPS) (polybutadiene-gra/f-polystyrene) has improved toughness and processability. The impact strength of polyamides is improved by blending with an ethylene copolymer or ABS rubber. 

Chlorinated poly (vinyl chloride) (CPVC) has increased Tg compared to PVC, and this increases its upper use temperature. Applications include hot- and cold-water pipe as well as pipe for the handling of industrial chemical liquids. Chlorinated polyethylene (CPE) finds use as roofing and other vapor barrier membranes, as pond liners, and as an additive to improve the impact strength of PVC. 

Fig, 29. Dependence of the impact strength of the composition poly(vinyl chloride), epoxy resin, nitrile rubber on rubber content. 1 0% of SKN18M 2 5% of SKN18M 3 10% of... 

Actually, ABS can be considered as an impact modifier for PC. PC/ABS blends have been compatibilized with both maleic anhydride (MA)-grafted poly(propylene) (PP) and a solid epoxy resin of the bisphenol A type. Both compatibilizers are effective for formulations of an ABS content up to 30%. The the impact strength of the compatibilized blends was close to that of PC. However, above 40% ABS content, the impact strength decreases significantly (19). 

The use of a plasticizer helps to improve the impact strength of the resultant polymer. The plasticizer may be added at any point in the process so as to ensure that it is mixed well with the polymer. Preferred plasticizers include mineral oil, poly(butene)s, or a combination of both mineral oil and poly(butene)s. The amount of plasticizer used is 2- 4%. 

In HIPS, desirably the PS is the continuous phase including a discontinuous phase of rubber particles. The size and distribution of the rubber particles in the continuous PS phase can affect the properties of the HIPS. In blends of PS with other materials, the distribution of the noncontinuous phase in the continuous poly(styrene) phase is often similarly important (2). The impact strength of HIPS can go up to sevenfold of that of general purpose PS. 

Pleated sheet conformation, 30,31 PLEDs (polymeric light-emitting diodes), 218 Plexiglas, 62 Plunkett, Roy, 65-66 PMMA. See Poly(methyl methacrylate) Polartec (Polar Fleece), 194 Poly(6-aminohexanoic acid), 25 Poly(a methyl styrene), 20 Polyacetylene, 72, 73 Polyacrylamide, 20 Polyamides, 22, 28, 61, 146 biodegradable, 185 Polyaramids, 77, 86 Polybutadiene, 70,109,148,155 Poly butyl acrylate), 20 Poly(butylene isophthalate), 25 Polycaprolactam, 21 Polycarbonate (PC), 17, 48, 86, 140 biodegradable, 185 density of, 247 impact strength of, 143 permeability of, 163 Polychloroprene, 65 Polycondensation, 85, 90-91 interfacial, 91-92... 

Polymer Engineering and Science 41, No.3, March 2001, p.575-83 IZOD IMPACT STRENGTH OF A PRODUCT MOLDED OF POLY(VINYL CHLORIDE)/ IMPACT MODIFIER CONTAINING VOIDS (VOID MOD)... 

In the course of the oxidative coupling, the amine catalyst may frequently become chemically bound to the poly(phenylene ether). These amino groups cause a negative effect on the impact strength of the h-nal polymer. The compositions can be improved in respect to impact strength, by removing or inactivating a substantial proportion of the amino compounds. Polymers treated in this way are sometimes referred to as inactivated PPE. 

Harada, M., Ohya, T., lida, K. et al. (2007) Increased impact strength of biodegradable poly(lactic acid)/poly(butylene succinate) blend composites by using isocyanate as a reactive processing agent. Journal of Applied Polymer Science, 106 (3), 1813-1820. 

Some commodity plastics have low impact strengths. Of course, the impact strength can be strongly increased by blending with other polymers (see also Section 35.3.5.3), which, in the case of the quite brittle poly(styrene), can be achieved by copolymerization, by graft polymerization in the presence of polydienes, or by styrene polymerization in the presence of poly (2,6-dimethyl phenylene oxide.) Poly(vinyl chloride) is also made less brittle by reinforcing with poly(acrylates). 

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