Regensburg 2013 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 19: Poster: Crystallization, Nucleation and Self Assembly
CPP 19.3: Poster
Tuesday, March 12, 2013, 18:15–20:15, Poster C
Unusual crystallization kinetics in poly(1,1-dimethyl silacyclobutane) — •Junyu Li1, Schönberger Astrid2, Kuttich Björn1, Johannes Elbert2, Gallei Markus2, Stühn Bernd1, and Rehahn Matthias2 — 1Experimental Condensed Matter Physics, TU Darmstadt — 2Ernst-Berl-Institute for Technical and Macromolecular Chemistry, TU Darmstadt
The crystallization behavior of poly(1,1-dimethyl silacyclobutane) (PDMSB) with molecular weight ranging between 3.000 and 50.000 kilodalton has been studied through Small Angle X-ray Scattering (SAXS), X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC). Well-defined PDMSB homopolymers with polydispersity index less than 1.2 have been prepared by living ring-opening anionic polymerization. It has been found that in the cooling process only one crystallization peak was observed by DSC, however, in subsequent heating process two obvious melting peaks appeared. SAXS results show that there is only one long range order. DSC measurements also show that when isothermal crystallization temperature Tc is low enough, there will be two melting peaks, but only one melting peak when Tc is high. The value of lower melting peak Tm1 increases with Tc, showing the increase of lamella thickness due to increase of Tc. However, the value of higher melting peak Tm2 stays constant with Tc. In addition,surface-attached PDMSB on polystyrene particle was studied. DSC results show that only one melting peak was observed independent of Tc. Based on these observations, re-crystallization is suggested to explain this interesting phenomenon.