Hard rubber dust

Hard rubber presents a fire hazard when reduced on steam-heated rolls (see subsection Organic Polymers ). Its dust is explosive [Twiss and McGowan, India Rtwber]., 107, 292 (1944)]. 

Descriptions of explns given by various dusts are given in refs 1 (aluminum), 4(hard rubber), 5 (organic materials), 7 (Al-bronze)t... 

The resins in the friction dust area tend to be rigid and the flexibility and plasticity associated with the long alkyl chain of phenolic lipids have been used in natural rubber vulcanisation by for example incorporating crosslinking with phosphorylated cardanol (ref. 252). Unpolymerised CNSL phenols have been used in natural or diene rubber compositions for tyre treads to give an improved dynamic elastic modulus but with the same hardness as formulations without the phenolic addition (ref. 253). 

Properties Wh. coarse powd. 95% thru 325 mesh 6.2 median particie size sp.gr. 2.65 dens. 22.07 ih/gai surf, area 1.3 nf/g oil absorp. 27 ret. index 1.54-1.55 pH 6.5 hardness (Mohs) 6.5 Use Level 30-70% (butfing/polishing), 60 phr (urethane rubber), 60% (adhesives), 65-75% (plastics), 0.5% (antiblock in LDPE film) Toxicology Prolonged inh. of dust may cause silicosis may cause cancer Imwitor 161 [Sasol Germany Sasol N. Am.]... 

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