Critical roles of molecular dynamics in the superior mechanical properties of isotactic-poly (1-butene) elucidated by solid-state NMR
Isotactic-poly(1-butene) (iPB1) shows superior mechanical properties after crystal–crystal transitions. Recently, Miyoshi et al. found that crystalline stems in metastable tetragonal crystal perform uniaxial rotational diffusions accompanying side-chain conformational transitions in the fast motional limit (correlation time, 〈τc〉 10 s). In addition, lamellar thickness, 〈l〉 of iPB1 and a low isotacticity iPB1 (low_iPB1) with 〈mmmm〉=78%, respectively, were investigated by small-angle X-ray scattering. The low_iPB1 sample shows very week supercooling dependence of 〈l〉 (∼5 nm), whereas iPB1 shows strong supercooling dependence of 〈l〉 (10–28 nm). On the basis of molecular dynamics and 〈l〉 results, molecular dynamics effects on structures and unique mechanical property of iPB1 are discussed.
Miyoshi, Toshikazu and Mamun, Al, "Critical roles of molecular dynamics in the superior mechanical properties of isotactic-poly (1-butene) elucidated by solid-state NMR" (2011). Polymer Science Faculty Research. 324.