Editing Polypropylene (section)

{{short description|Thermoplastic polymer}}
{{Chembox
|verifiedrevid  = 47717187
|Name = Polypropylene (PP)
|ImageFile1 = Polypropylen.svg
|ImageSize1 = 100px
|ImageClass1 = skin-invert-image
|ImageFile2 = Polypropylene isotactic mini trp.png
|ImageName2 = Polypropylene isotactic
|ImageClass2 = bg-transparent
|ImageFile3 = Polypropylene syndiotactic mini trp.png
|ImageName3 = Polypropylene syndiotactic
|ImageClass3 = bg-transparent
|IUPACName = Poly(1-methylethylene)
|OtherNames = Polypropylene; Polypropene;<br />Polipropene 25 [USAN]; Propene polymers;<br />Propylene polymers; 1-Propene; [-Ch2-Ch(Ch3)-]n
|Section1 = {{Chembox Identifiers
|CASNo_Ref = {{cascite|correct|CAS}}
|UNII_Ref = {{fdacite|correct|FDA}}
|UNII = 1ASA949VIC
|CASNo = 9003-07-0
|ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
|ChemSpiderID = None
}}
|Section2 = {{Chembox Properties
|Formula = (C<sub>3</sub>H<sub>6</sub>)<sub>n</sub>
|Density = 0.855 g/cm<sup>3</sup>, amorphous <br />0.946 g/cm<sup>3</sup>, crystalline
|MeltingPtC = 130 to 171
}}
}}
'''Polypropylene''' ('''PP'''), also known as '''polypropene''', is a [[thermoplastic]] [[polymer]] used in a wide variety of applications. It is produced via [[chain-growth polymerization]] from the [[monomer]] [[Propene|propylene]].

Polypropylene belongs to the group of [[polyolefin]]s and is [[Crystallization of polymers#Degree of crystallinity|partially crystalline]] and [[Chemical polarity#Nonpolar molecules|non-polar]]. Its properties are similar to [[polyethylene]], but it is slightly harder and more heat-resistant. It is a white, mechanically rugged material and has a high chemical resistance.<ref name="Ullmanns">{{Ullmann |doi=10.1002/14356007.o21_o04.pub2|title=Polypropylene |year=2014 |last1=Gahleitner |first1=Markus |last2=Paulik |first2=Christian |pages=1–44 |isbn=9783527306732}}</ref>

Polypropylene is the second-most widely produced [[Commodity plastics|commodity plastic]] (after [[polyethylene]]).