Char friction

From eq. (10.3), the thermal diffusivity is proportional to the HRR, where the thermal diffusivity would cause a small change in the HRR when no carbonaceous chars are formed during combustion. This can be confirmed by the results for HRR in PMMA/FR/MWCNTs. Because the addition of MWCNTs does not produce carbonaceous chars, the char friction can be neglected in the equation. Hence, the HRR is controlled by the term of thermal... 

Features Elec, insulator low dielec, const. high temp, stability inert nonwetting high dens., high purity, low surf, area tor improved blend chars., high thermal conductivity, low coeff. of friction, improved chem. stability... 

Definition Thermoplastic with exc. chem./thermal resist., low coeff. of friction, high elec, insulation, high stress crack resist., chem. inertness, toughness, flexibility, nonaging and nonstick chars., negligible moisture absorp. 

POSS exhibits several secondary effects which, when combined with primary or other secondary effects, can lead to commercial adoption. Thus, one may decide to use POSS for a primary benefit such as flow enhancement in a high temperature thermoplastic and see additional benefits such as improved mold-release, lower part friction [16,17], and better surface finish. Another known benefit is flame retardance. POSS does not provide stand-alone flame retardance but it has been reported to be an effective synergist when used in conjunction with primary flame retardants. Under combustion conditions, the POSS vitrifies [18] to form a char that provides some intumescent flame inhibition (Chapter 17). 

Features Offers Inc. wear resist., reduced coeff. of friction, and antiblocking char. Properties Off-wh./beige free-flowing powd. 10 p avg. particle size disp. in water ... 

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