The determination of which material is better relies heavily on the specific use. Tungsten prevails in terms of toughness and tolerance to high temperatures due to its record-breaking melting point. making it a popular choice for applications that require extreme heat resistance. Alternatively. titanium's lightweight yet robust nature makes it a frequent option in aerospace. medical equipment. and jewelry manufacturing. Furthermore. titanium boasts greater corrosion resistance compared to tungsten. Ultimately. choosing between tungsten and titanium depends on prioritizing the desired qualities for the given application.

Titanium dioxide is a common ingredient in sunscreen and makeup, serving mainly as a pigment and providing UV protection. It's considered safe for use on the face by various health authorities, including the FDA. However, in nanoparticle form, which enhances UV protection without leaving a white cast on the skin, there has been some debate about its potential for causing harm when inhaled or absorbed. In lotions and creams applied to the skin, it's generally regarded as safe, but inhalation of powdered forms should be avoided. Individuals with sensitive skin should patch test products containing titanium dioxide to ensure no adverse reactions occur.

Polypropylene (PP) is formed through the polymerization of propylene monomers, a process mostly catalyzed by titanium chloride or Ziegler-Natta catalysts under specific conditions. Most commonly, the polymerization can be achieved through either bulk, gas phase, or slurry phase processes, each differing by the medium in which the reaction takes place. For instance, in bulk polymerization, liquid propylene serves as both solvent and monomer, making it a cost-effective method for PP production. The choice of catalyst and polymerization method plays a crucial role in determining the molecular weight, crystallinity, and eventual mechanical properties of the PP produced. Innovations in catalyst technology have also led to the development of metallocene polypropylene, offering enhanced features such as improved clarity and higher impact resistance. Adjusting parameters like temperature and pressure allows for the production of PP with desired characteristics for various applications, from packaging materials to automotive parts.