Brabender plastograph

The mastication equipment most commonly employed is standard rubber instrumentation such as roll mills, internal mixers, extruders or laboratory devices modeled on them (e.g., a single-rotor internal masticator described by Wilson and Watson (43), die model improved by Kargin and coworkers (11) and the Brabender plastograph). 

An interesting study was performed by Guyot and coworkers (86-88) on poly(vinyl chloride) systems using the Brabender Plastograph. They divided the added monomers in two classes those which possess sufficient intermolecular ... 

Akutin (52) performed an exhaustive study on the influence of processing conditions and the nitrile rubber/poly(vinyl chloride) ratio on the mechanical characteristic of the product. The experiments were carried out in a Brabender Plastograph at 160-180° C and rotor speed of 10-50 rpm. The polyfvinyl chloride) molecular weight was 83500. A resin with an epoxy group content of 20.75% was added to the blend as plasticizer and stabilizer. Figure 29 shows that the... 

It is of some interest that the mechanical treatment of poly(vinyI chloride) under conditions of high shear stress in the melt, in a Brabender Plastograph, was found to increase the degree of LCB, as estimated from deviations from the Mark-Houwink equation 204). This is presumably due to chain scission under the influence of the shear stress followed by attack of the radicals produced on other polymer chains, and subsequent recombination reactions. 

To evaluate extensively the processability of PVC/EPR and to compare it with that of PVC having roughly the same molecular weight, we carried out a set of measurements by a capillary extrusion rheometer and Brabender plastograph. Other runs were carried out by an industrial size extruder. 

Figure 7. Variation of consistency as a function of time measured by a Brabender plastograph for a crude PVC/EPR and a PVC homopolymer...

Composites of 5 m/m% clay content were prepared in EVA copolymer matrix in a Brabender plastograph. In model studies, laser pyrolysis (LP) has been applied, using a C02 laser, for modeling the effect of fire, as described recently [37,38], The method was established by the basic work carried out by Price et al. [39], The effect of MMT of Fe-enriched surface layer (MMT-Fe) on the amount and composition of the evolved gas, compared to pristine EVA, can be seen in Figure 13.6. 

Checks on raw material sometimes are made by using a small single-screw extruder as a rheometer, or a test machine designed for the purpose—such as a Brabender Plastograph (a device for measuring torque, which may be attached for the purpose to a small extruder). 

Torque Rheometer. The Brabender plastograph was also used to study the relative processing stabilities of the polymers. The conditions were those recommended by P. G. O Leary (24). The melt viscosity-time curves are shown in Figure 10. Resins D, I, and E are the least stable, and A, H, G, and B are the most stable. 

Van Henten, at the Shell Plastic Laboratories (II), showed that styrene-butadiene block polymers can be blended with commercial HIPS to upgrade its impact strength to 5.8 ft-lbs/inch. Childers, at Phillips Petroleum (12), blended commercial polystyrene with block polymers in a Brabender plastograph. To control rubber particle size he added a peroxide during the blending operation, thereby creating crosslinks. With this technique he achieved an impact strength of 5.9 ft-lbs/inch. 

For economic reasons we achieved the same quality blends by mechanically mixing commercial polystyrene with the block polymers. Good quality products were obtained from two-roll mills, the Brabender plastograph, the Banbury mixer, and continuous high intensity mixers. 

In addition to the torsion plastograph mentioned above, a number of other methods are used for appraising the properties of plastic bodies in practice. Plastic strength (rigidity) is determined by means of the Rebinder penetrometer which measures the depth of penetration of a cone forced into the body under constant load. The respective quantity is related to yield point. The commercial Brabender plastograph measures the resistance of mixture to kneading. The extrusion viscometer, from which the material is extruded under pressure, is analogous to flow-out viscometers. 

Rheometrv. The following rheometers were used in this study An Instron capillary rheometer, a Rheometries mechanical spectrometer, used in both cone and plate mode as well as in the biconical mode, and a Brabender Plastograph (4). 

Compounding LDPE with Ti02 agd carbon black (CB) was performed in a Brabender Plastograph for 10 min at 90 rpm under nitrogen. The mixing chamber volume was 60 ml and the oil bath temperature 160 C. The antioxidants (AO) were incorporated by dry blending of 25 kg LDPE with AO and then extrusion and granulation... 

The lowest power expense and maximum homogeneity of the mix can be attained by optimum agitation of the rubber binder, fillers, and reinforcing fibers with the Brabender plastograph mixer. Such mixers allow estimation of the technological properties of rubber compositions based on viscous resistance, which in turn depends on duration of mechanical effects and temperatures. 

The effect of PP and PE ratios has been studied earlier (45 7) when itaconic acid (lA) was grafted to their blends containing L-101 peroxide as the initiator. Grafting was done in the extruder reactor assembled on the base of Brabender plastograph (Duisburg, Germany) equipped with the dynamic mixer (48,49). 

The results reported in this paper are characteristic not only of grafting of lA onto PP/PE blends carried out in the Brabender plastograph equipped with a dynamic mixer, but also of lA grafting performed in reactors of other types, particularly in a single-screw extruder. 

We proved this presumption on blends of PA6 with LDPE and HOPE and on a blend of PE with ethylene-propylene rubber (EPDM). The polyolefin components were functionalized by grafting 1 wt% of itaconic acid (lA) (51,53). Functionalization and preparation of the blends were performed in a static mixer assembled onto the Brabender plastograph (51,73). Grafting with simultaneous cross-linking of PO resulted in a sharp reduction of MFl values and r] of their melt. It can be seen in Table 18.1 that g-POs possess much higher melt viscosities than PA6. The viscosity of LDPE exceeds r] of PA6 by two decimal orders. of PA6 is twice as low as that of... 

Commercial instruments are available the Brabender Plastograph, and Plasticorder, this latter allowing use of an extruder head the RAPRA variable torque rheometer [5]. The advantages of these instruments are based on the similarity of their action to full-scale extrusion equipment and on the fact that they can be operated at shear rates appropriate for factory equipment. But because of the difficulty of matching exactly the range of shear rates which exist in full-scale plant, successful scaling-up is difficult. Elongation flow measurements have been reported by several workers, in which a sample is stretched in uniaxial tension at a constant strain rate [6]. 

Torque Brabender Plastograph High Average Measurement can be carried out with the material used in production... 

Further evidence of the tightness of the network developed was provided by thermomechanical studies using a Brabender plastograph. The higher the functionality, the greater the resistance to shearing and the shorter the time to reach maximum torque. 

The Brabender plastograph is nsed to measure the work of mixing of a typical formulation. A rapid change in torqne during gel formation results from gelation. This is a typical method used to select the conditions of manufacture for the plasticized compositions. 

Figure 3.15 Brabender Plastograph recording during preparation of a thermoplastic-elastomer...

Figure 3.21 Brabender Plastograph results for TPV preparation by dynamic vulcanization.

In his turn, Baramboim followed the degradation of some copolymers of butadiene with styrene and acrylonitrile, in the conditions of mastication on a Brabender plastographer [708]. 

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