Composites impact strength

A typical unsaturated unreinforced polyester resin has an extremely low notched Izod impact strength. The addition of fibrous glass can change this extremely brittle material into a high impact strength composite. The same phenomenon occurs with some brittle thermoplastics, such as polystyrene and styrene—acrylonitrile. 

Super-tough poly(sulfone)s can be produced by blending PES with acrylate rubber and a polycarbonate as an impact modifier. From this high impact strength composition, films and molded articles are useful in automotive applications, durable goods and appliances, medical and plumbing applications where resistance to hot, humid environments may be particularly important, and safety equipment and protective gear. 

Polystyrol BASF AG improved impact strength. Composition-dependent modulus, toughness, ductility, transparency, and gloss... 

Themould with dimensions 120 x 60 x 4 mm was used for preparing samples to determine the impact strength. Composites were prepared in a similar manner described above, using untreated and alkali treated fibres. 

Production of high impact strength composites requires long fiber reinforcement with nonperfect adhesion with the polymer matrix. 

The routine compositional and functional testing done on the adhesives includes gas chromatographic testing for purity, potentiometric titrations for acid stabilizer concentrations, accelerated thermal stabiUty tests for shelf life, fixture time cure speed tests, and assorted ASTM tests for tensile shear strengths, peel and impact strengths, and hot strengths. 

Hardness, Impact Strength. Microhardness profiles on sections from explosion-bonded materials show the effect of strain hardening on the metals in the composite (see Hardness). Figure 8 Ulustrates the effect of cladding a strain-hardening austenitic stainless steel to a carbon steel. The austenitic stainless steel is hardened adjacent to the weld interface by explosion welding, whereas the carbon steel is not hardened to a great extent. 

To introduce some interfacial physico-chemical linkage between EVA and PRP, blends were made by adding different quantities of M AH-PP. Some results are demonstrated in Table 12, The physico-mechanical properties of the PRP-EVA compositions modified with MAH-PP showed that properties are influenced by MAH-PP concentration. Compositions with better impact strength and improved brittleness can be prepared by varying the modifier concentration. Tensile strength and elongation are not significantly influenced by the addition of a modifier. An increase in the modifier con-... 

Table 8 Effect of Composition of TMTD Curing System on the Charpy Notched Impact Strength (ai<) for 85/15 and 80/20 PP/EPDM Blends...

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