Editing Polypropylene (section)

===== Syndiotactic polypropylene (sPP) =====
Syndiotactic polypropylene was discovered much later than isotactic PP and could only be prepared by using [[metallocene catalysts]]. Syndiotactic PP has a lower melting point, with 161 to 186&nbsp;°C, depending on the degree of tacticity.<ref name="DerosaAuriemma2006">{{cite journal |last1=De Rosa |first1=C |last2=Auriemma |first2=F |year=2006 |title=Structure and physical properties of syndiotactic polypropylene: A highly crystalline thermoplastic elastomer |journal=Progress in Polymer Science |volume=31 |issue=2 |pages=145–237 |doi=10.1016/j.progpolymsci.2005.11.002}}</ref><ref>{{cite book |doi=10.1021/bk-1992-0496.ch008 |chapter=Structure and Morphology of Highly Stereoregular Syndiotactic Polypropylene Produced by Homogeneous Catalysts |title=Catalysis in Polymer Synthesis |volume=496 |pages=104–20 |series=ACS Symposium Series |year=1992 |last1=Galambos |first1=Adam |last2=Wolkowicz |first2=Michael |last3=Zeigler |first3=Robert |isbn=978-0-8412-2456-8 }}</ref><ref>{{cite journal |doi=10.1016/0032-3861(94)90978-4 |title=Crystallization, melting and morphology of syndiotactic polypropylene fractions: 1. Thermodynamic properties, overall crystallization and melting |journal=Polymer |volume=35 |issue=9 |pages=1884–95 |year=1994 |last1=Rodriguez-Arnold |first1=Jonahira |last2=Zhang |first2=Anqiu |last3=Cheng |first3=Stephen Z.D |last4=Lovinger |first4=Andrew J |last5=Hsieh |first5=Eric T |last6=Chu |first6=Peter |last7=Johnson |first7=Tim W |last8=Honnell |first8=Kevin G |last9=Geerts |first9=Rolf G |last10=Palackal |first10=Syriac J |last11=Hawley |first11=Gil R |last12=Welch |first12=M.Bruce }}</ref>