Molecular Chain Movements and Transitions of SEBS above Room Temperature Studied by Moving-Window Two-Dimensional Correlation Infrared Spectroscopy

Abstract

The temperature-dependent molecular chain movements and transitions of polystyrene-block-poly-(ethylene-co-1-butene)-block-polystyrene block copolymer (SEBS) above room temperature were studied by insite infrared spectroscopy combined with moving-window two-dimensional (MW2D) correlation spectroscopy. Some complex molecular chain movements and transitions of SEBS were revealed with the linear incremental temperature increasing (30-166 °C). The melting point of the extraordinary weak crystal of -(CH 2 -CH 2 )n in the poly(ethylene-co-1-butene) block (EB) is determined at 48 °C. The heat enthalpy relaxation of polystyrene block (S) of SEBS, which is induced by the framework movement of the side benzene ring and the melting of the weak crystal in the polystyrene block, is observed around 72-80 °C from the MW2D correlation spectrum. The glass transition temperature of the polystyrene block is determined around 120 °C. From the MW2D correlation spectrum, we discover that, around 120 °C, the chain segment movement of polystyrene block occurs before that of poly(ethylene-co-1-butene) block in phase interface. At 142 °C, the fundamental chains of the disperse phase (S block) center initiate to entirely move and this type of movement drives a fraction of the disperse phase (S block) to deform from an incomplete shape to a sphere. This corresponds to the entirely viscous flow temperature of the fundamental chains of the disperse phase.

A reversible functional supramolecular material formed by host–guest inclusion

“…Such cooperative motion of the local structures is expected when strong interactions exist among different groups. [23][24][25][26] The cross-peaks in Fig. 1a show that the IR bands of Fc and bCD were correlated, which meant that Fc and bCD groups in the PEI-Fc/Em-bCD complex strongly interacted with each other due to the formation of inclusion complexes.…”

Rheological characterization of nanostructured material based on Polystyrene-b-poly(ethylene-butylene)-b-polystyrene (SEBS) block copolymer: Effect of block copolymer composition and nanoparticle geometry

“…This interphase is a transitional region between adjacent pure PS and EB domains where the chain segments of both blocks coexist. According to Zhou et al [35], small weak crystalline of EB segments exists within both EB domains and phase interphase. At the interphase region, these EB crystallines are surrounded by PS chain segments.…”

Two-dimensional correlation spectroscopy — Biannual survey 2007–2009

“…For example, Zhou et al [70] used moving window analysis for the study of transition temperatures of tri-block copolymer. Melting of very weak crystal of poly(ethylene-co-1-butene) middle block around 48°C and the onset of polystyrene segmental motion, corresponding to the glass transition near 120°C, could be detected.…”

“…Likewise, Jung et al [43] studied transition temperatures of a spin coated polymer film. Zhou et al [70] studied transition temperatures of a copolymer. Morita et al [76] used 2D IR for the study of the temperature effect on a poly(vinyl alcohol) film to track complex changes in IR spectra due to melting and thermal degradation.…”

“…Zhou et al [70] analyzed a tri-block copolymer, comprising poly(ethylene-co-1-butene) middle block and polystyrene blocks. Meng et al [168] carried out 2D ATR-IR study of a hydrogel made of PEO-PPO-PEO block copolymer or phospholylchorine-modified version of the block copolymer.…”