Rotational molding impact modifiers

In addition to zero-shear viscosity, material elasticity plays an important role in determining coalescence behavior in the rotational molding process.For rotational molding grade material, this effect was first recognized from the experimental results obtained with impact modified polypropylenes and is illustrated in Fig. In this work, the relative elasticity of resins... 

Nylon 11 n (polyundecanamide) A type of nylon produced by polycondensation of the monomer 11-aminoundecanoic acid, a derivative of castor oil. It is available in the form of fine powders for rotational molding and other powder processes and in pellet form for extrusion or molding. Like nylon 12, nylon 11 has properties intermediate between those of nylon 6 and polyethylene good impact strength, hardness, and abrasion resistance, but other mechanical properties are lower than those of most other nylons. However, due to its exceptionally low water absorption, the dimensional stability of nylon 11 is high. A modified nylon 11 trade named Rilsan N is flexible, transparent, and self-extinguishing. 

PP/EPDM Blends To improve impact properties of PP, the resin is usually modified by incorporation of an elastomer. Since the performance depends on morphology, radiation crosslinking was used in its stabilization [van Gisbergen et al., 1989a] (Table 11.9). The blends were made either in a two-roll miU, at 185°C, then compression molded into 1-mm-thick sheets, or in a co-rotating twin-screw extruder, then pelletized. The irradiations (100 kGy) were done using a 3-MeV electron accelerator. Irradiated and non-irradiated pellets were injection-molded. Eor the DSC measurements, the samples were melted at 200°C, quenched to 110°C, and then heated at a rate of 10°C/min. 

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