Carbon black weight change

Strips of JPN proplnt, containing 51.4 weight percent NC, 42.9 NG, 3.23 diethyl phthalate, 1.25 K sulfate, 1.00 ethyl centralite, 0.2 carbon black, and 0.02 candelilla wax, were exposed to total doses of 1 to 5 x 106 R at a dose rate of 1.93 x 10s R/hr at Co60 sources at Brookhaven National Laboratory. Significant changes were observed in the viscosity of NC, the available centralite stabilizer, and the stability of the proplnt. Viscosity measurements indicated the degradation of the NC polymer chains. The highest dose sample was approx comparable in stability to a similar proplnt produced by an... 

In studying the effect of heat on calcium carbonate, Black measured the loss of weight involved. He also measured the quantity of calcium carbonate that would neutralize a given quantity of acid. This was a giant step toward the application of quantitative measurement to chemical changes, a method of analysis that was soon to come to full maturity with Lavoisier. 

Effects of changes in the concentrations of accelerator and sulfur on vulcanizate properties have been studied by using the following recipe (parts by weight) natural rubber, 100 N330 carbon black, 50 N-isopropyl-N -phenyl-p-phenylenediamine (IPPD antidegradant) 2 zinc oxide, 5 stearic acid, 3 plasticizer, 3 sulfur, variable N-cylohexylbenzothiazolesulfenamide (CBS), variable (Coran, 1978). 

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... 

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