Polypropylene

Chemical Description 

• The main uses of homopolymer PP include extrusion blow grade, flat yarn grade, injection grade, fiber grade, and blown film grade.
• Can be used for packaging straps, blowing bottles, brushes, ropes, woven bags, toys, folders, electrical appliances, household items, microwave lunch boxes, storage boxes, packaging paper films.
• Polypropylene is a low-density resin that offers a good balance of thermal, chemical, and electrical properties, along with moderate strength.
• Strength can be significantly increased by using reinforcing agents such as glass fiber.
• Polypropylene has limited heat resistance, but it can be used in applications that must withstand boiling water or steam sterilization.
• Polypropylenes can resist chemical attack and are unaffected by aqueous solutions of inorganic salts or mineral acids and bases, even at high temperatures.
• They are not attacked by most organic chemicals, and there is no solvent for these resins at room temperature.
• The resins are attacked, however, by halogens, fuming nitric acid, other active oxidizing agents, and by aromatic and chlorinated hydrocarbons at high temperatures .
• Polypropylene is translucent and autoclavable. Properties can be improved by compounding with fillers, by blending with synthetic elastomers, and by copolymerization with small amounts of other monomers.
• Polypropylene (PP) is a thermoplastic material used in a wide variety of applications including packaging, labeling, textiles, etc.
• Due to high processability and low cost, PP is one of the most extensively produced polymers, especially for the auto industry.
• Pristine PP is resistant to photo-oxidation and thermal oxidation at moderate temperatures.
• However, PP is sensitive to various external aging environments (such as heat, light, and radiation), and, hence, has a relatively low service temperature.
• When PP is exposed to high temperatures or to an irradiation environment, the tertiary hydrogen atoms present in PP chains are susceptible to be attacked by oxygen.
• It is well known that PP oxidation depends on both light and temperature in outdoor aging conditions.
• PP can also be photo-degraded because several molecular chains are affected in the wavelength range from 310 to 350 nm.