Table 4. Effectiveness Index of Various Fillers at Three Reinforcing Parameters Based on 100% Modulus

Filler type	Volume fraction (ϕf)	Effectiveness index (ϕSRF/ϕf)	Primary particle size (nm)	Primary Particle shape
SRF	0.186	1.0	70-96	Globular
HS45	0.154	1.2	50-70	Globular
C-CaCO3	0.376	0.5	1,700-2,300	Globular
200MP	0.107	1.7	5-40	Globular
MWCNT	0.036	5.2	10-15	Fibril

Outer diameter of single MWCNT strand.