Innovative Application of Biopolymer Keratin as a Filler of Synthetic Acrylonitrile-Butadiene Rubber NBR

Table 4

The influence of keratin on the mechanical properties of NBR vulcanizates.

Parameters	Symbol
	Standard	Sample I	Sample II
Tensile stress [MPa] at an elongation:
100%	1,48 ± 0,03	1,08 ± 0,03	2,03 ± 0,01
200%	1,90 ± 0,04	1,50 ± 0,04	2,44 ± 0,01
300%	2,15 ± 0,00	1,91 ± 0,03	3,17 ± 0,02
TS—tensile strength [MPa]	2,23 ± 0,01	2,33 ± 0,01	2,90 ± 0,04
Eb—elongation at a break [%]	352 ± 2	382 ± 2	311 ± 3
𝑆—the ageing coefficient [—]	0,65 ± 0,00	0,80 ± 0,04	0,90 ± 0,04
Shore’s hardness 𝐴  [IHRD]	46,8 ± 0,3	48,2 ± 0,2	48,1 ± 0,3
Shob’s elasticity [%] (scale 𝐻=1)	28	24	26
Shock absorption—the number of pendulum leanout	8	5	6
𝜍𝑉—volume resistance [m∗Ω]	9,787 * 10^8	12,246 * 10^12	6,507 * 10^8
𝜍𝑆—surface resistance [m∗Ω]	8,572 * 10^10	5,790 * 10^10	5,511 * 10^10