This polymer is produced by the addition polymerization of propylene, CH =CHCH (propene). Its 2 3
molecular structure is similar to that of polyethylene, but has a methyl group (–CH ) on alternate carbon 3
atoms of the chain. Its molar masses falls in the range 50,000 to 200,000 grams. Polypropylene (PP) is
slightly more brittle than polyethylene, but softens at a temperature about 40EC higher. Polypropylene is
used extensively in the automotive industry for interior trim, such as instrument panels, and in food packaging, such
as yogurt containers. It is formed into fibers of very low absorbance and high stain resistance, used in clothing and
home furnishings, especially carpeting.