Polypropylene (PP) is widely recognized for its outstanding combination of properties, including its toughness, which is a measure of a material's ability to absorb energy and deform without fracturing. This thermoplastic polymer exhibits excellent resistance to fatigue, making it ideal for applications where parts are subject to repeated stress. Its toughness is attributed to its semi-crystalline structure, which provides a good balance between strength and flexibility. However, the material's toughness can be affected by factors such as temperature, the presence of any fillers, and molecular weight. At lower temperatures, PP becomes more brittle, reducing its toughness. To enhance its properties, polypropylene can be copolymerized with ethylene. This co-polymerization improves impact resistance, especially at lower temperatures, thus widening its application range. Therefore, while inherently tough, the actual performance of polypropylene can be tailored to meet specific demands through material formulation and processing conditions.

In the Earth's crust. titanium is found as rutile. ilmenite and ores. Major ore mining countries include Australia. Canada. China. Norway. South Africa and Ukraine. However. titanium is not a pure metal; it always exists as a compound. A complex process is required to extract titanium from the ore.

White zirconia is usually shinier than white topaz due to its high refractive index.