Studies on the use of nano zinc oxide and modified silica in NR, CR ...

Chapter 4
reinforcement and this supports the good accelerating effect of ZnO(p) and
ZnO(s) compared to conventional zinc oxide.
Other technological properties
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Other technological properties like hardness, compression set values
and abrasion loss for gum vulcanizates are given in Table 4.5.
Table 4.5 Technological properties of gum vulcanizates
Property N-1 N-2 N-3 N-4
Hardness(Shore A) 45 45 46 40
Compression set (%) 42.57 41.05 37.03 49.25
Abrasion loss (cc/hr) 5.26 4.75 4.48 5.80
Hardness, compression set and abrasion resistance for N-1, N-2, and
N-3 vulcanizates are superior compared to N-4 vulcanizate. It is clear from
the table that the hardness and compression set values of N-2 and N-3
vulcanizates are comparable with N-1 vulcanizate. The abrasion loss values
for N-2 and N-3 vulcanizates are lesser than N-1 vulcanizate. This indicates
that low dosage of ZnO(p) and ZnO(s) are enough to get the same strength as
that with higher dosage of conventional ZnO.
4.3.3 Properties of filled composites
Tensile properties
Compound
Table 4.6 Tensile properties of filled vulcanizates
Tensile strength
(MPa)
Elongation at
break (%)
Tensile modulus at
300% elongation (MPa)
Tear
strength (N/mm)
N-5 31.04 893 6.32 105
N-6 32.26 826 7.76 107
N-7 31.48 849 6.41 104
N-8 26.03 946 4.75 80