Order and segmental mobility during polymer crystallization: Poly(butylene isophthalate)

Abstract

The influence of the development of crystalline structure on the segmental dynamics of the amorphous phase in poly(butylene isophthalate) (PBI) has been studied by a combination of relaxation and scattering techniques. By means of dielectric spectroscopy (DS) the dynamics of both amorphous and semicrystalline PBI samples has been observed in a wide frequency and temperature range. The evolution of the crystalline phase with time has been studied in a range of temperatures, starting from initially glassy PBI by simultaneous small and wide angle X-ray scattering (SWAXS). By using a state-of-the-art setup designed specifically for the in situ study of both DS and SWAXS simultaneously (SWD), the crystallization of initially amorphous PBI has been followed in real time from both the structural and dynamics points of view. The obtained results support a model based on two different regimes on crystallization and a heterogeneous distribution of lamellar stacks. During the first regime the primary stacks cause the apparition of a rigid amorphous phase (RAP), i.e. a phase of amorphous chains lacking segmental motion. During the second regime, however, no more RAP is observed, indicating that the new lamellae that appear during this stage are nearly individual and not forming lamella stacks. q

Interfacial interactions in PTT–PTMO/polyhedral oligomeric silsesquioxane (POSS) nanocomposites and their impact on mechanical, thermal, and dielectric properties

“…Several studies have already presented the dielectric properties of POSS/ polymer nanocomposites using dielectric spectroscopy (DS) [52][53][54]. Dielectric spectroscopy (DS) can be very sensitive method for analyzing the effect of polymer crystallization [55]. Therefore, for the neat PTT-PTMO and PTT-PTMO/1.0POSS nanocomposites, the DS measurement has been performed.…”

Studies on the structural heterogeneities of poly(dimethylsiloxane) networks modified with poly(phenylsilsesquioxane)s using small-angle X-ray scattering and dynamical mechanical analysis

“…Another possibility for explaining this correlation peak could be the presence of crystallites inside the matrix [47][48][49][50][51], but the XRD plot for this membrane did not show any evidence for crystallinity at room temperature [43]. This fact suggested that the membrane M2 was composed by richer-PPSQ/SiO 2 and PDMS/SiO 2 phases.…”

Miscibility Behavior of Poly Ethylene Glycol or Poly Ethylene Succinate/Chlorinated Poly Vinyl Chloride Blends Studied by Dielectric Relaxation Spectroscopy

“…This crosslinking comes from the hydrogen bonds that formed between the oxygen of PEG and the α-hydrogen of the chlorine groups of CPVC structure. Therefore, α'-process for CPVC-PEG blend can be attributed to the rigid amorphous phases that located between adjacent lamella inside the lamellar stacks of CPVC [25,26].…”