Masterbatches, analysis

Results of a Fingerprint Analysis of a Masterbatch and Remill Mixing Process of a Styrene-Butadiene Rubber-Carbon Black (SBR-CB) Compound on a CK320E Intermeshing Mixer with PES3 Rotors (Harburg Freudenberger)... 

Industrial troubleshooting (defect and failure analysis at polymer, additive and masterbatch producers, or at polymer processors)... 

Table 8.47 shows the available options for the analysis of polymer processing aids, namely combustion and instrumental methods. The best method is dependent on PPA type, the level to be measured, and the available equipment (see also Section 8.2.1.2). Fluoropolymer processing aid concentrations can be determined by WDXRF configured to measure either fluorine or a tracer, and by EDXRF to analyse a tracer [29]. Calibration curves are required. At present, EDXRF or benchtop XRF units cannot directly measure fluorine. For resin or masterbatch producers who prefer to make on-line XRF measurements of processing aid concentrations (to letdown levels of 50-100 ppm), processing aids that contain a tracer (usually BaS04) are available. The analysis time is less than two minutes. 

The functionalization of EPDM with MA is carried out in a Berstorff 25 mm corotating twin screw extruder. EPDM (Keltan 740 DSM), Perkadox 14 (bis(tert. butyl peroxy isopropyl) benzene AKZO half life times 5 min at 175 °C 10 sec at 210 °C [4]) and Nourymix(50/50 wt% masterbatch of MA on polyethylene AKZO) were mixed and starved fed to the first section of the extruder. A nitrogen atmosphere was maintained over the reaction mixture throughout the extruder. In the last sections free maleic anhydride and other volatile components were removed by applying vacuum on the last vent. Standard extrusion conditions were throughput rate 1 kg/h residence time 5 minutes rotor speed 150 rpm Mass temperatures in the die 220-260 OC. The MA-content in the rubber was determined with potentiometric titration and infrared analysis. 

Albarino [30] used standards consisting of PE and Irganox 1010. These were made by milling at temperatures of about 127 "C. Samples containing 0.051 and 0.010% Irganox 1010 were made from a masterbatch containing 0.101% Irganox 1010. These standards and an unstabilised control were moulded into sheets 0.064 to 0.076 cm thick for use in the analysis. 

Techniques based on TG analysis have made it possible to readily and accurately measure the carbon-black content in commercial polymer formulations, such as in rubbers, at levels as far apart as 0.1% and 30%. The typical procedure is shown in Fig. 2.15 (sensitivity of the TG scan is 100 wt.% full scale) for a polyethylene masterbatch formulation, which was initially heated in N2 at a rate of 160°C/min. to about 550°C. Pyrolytic decomposition to gaseous products resulted in a 75% weight loss. After changing to O2 atmosphere the carbon-black is then oxidised [151]. The precision of the determination in the PE/CB masterbatch formulation is about 0.05 to 0.1% carbon (absolute). The TG method is fast, le. 6 min at 160°C/min, as compared to 2 h for ASTM D 1063 [266] without TG, thus providing substantial time savings. The compositional analysis (polymer and CB content) of LDPE has been reported [85] Affolter et al [155] have determined the content of carbon-black in polyolefins (2-3% CB) by TG following ISO 9924-1 and have noticed an inhomogeneous distribution in commercial... 

Maddock Screw Pineapple Triple flight Z LDPE Black masterbatch Window in die and camera and image analysis 1) Triple flight Z 2) Maddock 3) Pineapple 4) Screw [27]... 

Confirmation of crosslinks is possible using infra-red analysis. Following confirmation, the addition of antioxidant masterbatch should solve the problem (at increased material cost) providing good distributive mixing occurs. 

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