Question

Natural rubber is not used in making footwear for polar regions because:

• A. natural rubber becomes soft at temperature lower than ${10}^{o}C$
• B. natural rubber becomes brittle at temperature lower than ${10}^{o}C$
• C. natural rubber melts at temperature lower than ${10}^{o}C$
• D. natural rubber becomes stronger at temperature lower than ${10}^{o}C$

Answer 1

The correct option is B natural rubber becomes brittle at temperature lower than ${10}^{o}C$

Natural rubber is a thermoplastic. It becomes soft and sticky when heated at high temperature (lower than ${62}^{o}C$) and brittle at low temperature $\left({10}^{o}C\right)$. So that's why natural rubber is not used in making footwear for the polar region.