Crystallization from the amorphous form of the nanoporous ɛ form of syndiotactic polystyrene

✍ Scribed by C. Daniel; T. Montefusco; P. Rizzo; P. Musto; G. Guerra

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 736 KB
• Volume: 51
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2010.07.043

✦ Synopsis

The recently discovered channel-shaped nanoporous 3 crystalline form of syndiotactic polystyrene (s-PS) is generally obtained by a chloroform-induced recrystallization of samples exhibiting the helical g crystalline form, followed by chloroform desorption in suitable conditions. This nanoporous 3 crystalline form can be also obtained by crystallization of amorphous samples as induced by the same chloroform sorptionedesorption procedure. This procedure, which does not affect b form samples, when applied to samples exhibiting the trans-planar a form instead leads to a recrystallization into the cavity-shaped nanoporous d form. Both nanoporous crystalline forms (d and 3) are obtained, by this chloroform treatment on uniaxially stretched amorphous films. In particular, polarized FTIR microscopy clearly shows that d and 3 crystalline forms prevail in central and lateral film regions, respectively. In fact, in the film central regions, higher polymer draw ratios are reached that lead to higher degrees of trans-planar crystallinity, whose chloroform-induced crystallization leads to d form formation.