What are the chemical properties of polypropylene?

Polypropylene (PP), a polymer prepared catalytically from propylene which differs from HDPE by having an isostatic replacement of a hydrogen atom by a methyl group on alternate carbon atoms in the main chain. Polypropylene resins are used by customers to manufacture a diverse array of goods including consumer products, fresh food packaging, high-strength construction materials, automotive and electrical components, durable textiles, medical applications, pipe systems and many others.Polypropylene properties can be tailored including process conditions, copolymer components and contents, molecular weight and molecular weight distribution.
It is well suited for a variety of end uses, ranging from flexible and rigid packaging to fibres and large moulded parts for automotive and consumer products.Polypropylene is recyclable, an important consideration in many packaging and automotive applications, and it can be incinerated without toxic emissions.It can be processed using most methods including cast, blown and BOPP film extrusion, extrusion coating, blow moulding and injection stretch blow moulding, injection moulding and thermoforming. Its physical properties can be easily enhanced through additives.Most polypropylene used is highly crystalline and geometrically regular (i.e. isotactic) opposite to amorphous thermoplastics, such as polystyrene, PVC, polyamide, etc., which radicals are placed radomly (i.e. atactic).
PP has an intermediate level of crystallinity between low density polyethylene (LDPE) and high density polyethylene (HDPE); On the other hand PP has higher working temperatures and tensile strength than polyethylene.
In order to improve some properties PP formulas may include additives such as pigments, carbon black, rubbers, antioxidants, and UV stabilizer. PP is available as molding powder, extruded sheet, cast film, textile staple, and continuous filament yarn.The use of PP does not have any remarkable effect from an occupational health and safety point of view, in terms of chemical toxicity. The manufacture of the polymer at high temperature can released irritating vapors to respiratory system and eyes. There is no known effect from chronic exposure to this product.