Studies on the use of nano zinc oxide and modified silica in NR, CR ...
Studies on the use of nano zinc oxide and modified silica in NR, CR ...
Studies on the use of nano zinc oxide and modified silica in NR, CR ...
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Use <strong>of</strong> <strong>nano</strong> <strong>z<strong>in</strong>c</strong> <strong>oxide</strong> <strong>in</strong> chloroprene rubber<br />
c<strong>on</strong>venti<strong>on</strong>al ZnO vulcanizate. As <strong>the</strong> re<strong>in</strong>forc<strong>in</strong>g capacity <strong>in</strong>creases,<br />
generally <strong>the</strong> el<strong>on</strong>gati<strong>on</strong> at break (%) decreases. Vulcanizates with 2phr<br />
ZnO(p) <strong>and</strong> ZnO(s) show reduced el<strong>on</strong>gati<strong>on</strong> at break values compared to<br />
that <strong>of</strong> vulcanizate with 5phr c<strong>on</strong>venti<strong>on</strong>al ZnO. This aga<strong>in</strong> shows that 2phr<br />
ZnO(p) <strong>and</strong> ZnO(s) are better curatives than c<strong>on</strong>venti<strong>on</strong>al ZnO.<br />
O<strong>the</strong>r technological properties<br />
Table 5.7 Technological properties <strong>of</strong> filled vulcanizates<br />
Property C -5 C –6 C-7 C - 8<br />
Hardness (Shore A) 67 69 69 62<br />
Compressi<strong>on</strong> set (%) 19.12 16.91 17.36 20.84<br />
Abrasi<strong>on</strong> loss (cc/hr) 2.68 2.40 2.41 2.8<br />
Heat build-up(∆T) o C 13.2 12.2 13.3 13.9<br />
Flex resistance ( k cycles) 35.62 39.44 62.86 30.35<br />
The technological properties like hardness, compressi<strong>on</strong> set, abrasi<strong>on</strong><br />
loss, heat build-up <strong>and</strong> flex resistance were compared for <strong>CR</strong> vulcanizates<br />
with ZnO(p), ZnO(s) <strong>and</strong> c<strong>on</strong>venti<strong>on</strong>al ZnO <strong>and</strong> is given <strong>in</strong> <strong>the</strong> Table 5.7.<br />
Hardness, compressi<strong>on</strong> set, abrasi<strong>on</strong> loss, heat build-up <strong>and</strong> flex resistance for<br />
C-5, C-6 <strong>and</strong> C-7 vulcanizates are superior compared to C-8 vulcanizate.<br />
Abrasi<strong>on</strong> resistance, compressi<strong>on</strong> set <strong>and</strong> flex resistance are found to be<br />
superior for C-6 <strong>and</strong> C-7 vulcanizates. Hardness <strong>and</strong> heat build-up values <strong>of</strong><br />
C-6 <strong>and</strong> C-7 vulcanizates are comparable with that <strong>of</strong> C-5 vulcanizate with<br />
5phr c<strong>on</strong>venti<strong>on</strong>al ZnO. This <strong>in</strong>dicates low dosage <strong>of</strong> ZnO(p) <strong>and</strong> ZnO(s) are<br />
better curatives than high dosage <strong>of</strong> c<strong>on</strong>venti<strong>on</strong>al ZnO.<br />
Re<strong>in</strong>forc<strong>in</strong>g <strong>in</strong>dex<br />
Re<strong>in</strong>forc<strong>in</strong>g <strong>in</strong>dex values <strong>of</strong> composites with respect to tensile strength<br />
are given <strong>in</strong> <strong>the</strong> Table 5.8.<br />
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