Effects of Multiple Recycling on the Structure and Morphology of SEBS/PP Composites

Abstract

A study of the chemical, mechanical, rheological, and morphological properties of recycled styrene-ethylene-butylene-styrene/polypropylene (SEBS/PP) composites was performed to investigate the viability of the application of these materials as recyclable halogen-free alternatives to plasticized poly(vinyl chloride). The SEBS and PP were initially compounded in a ratio of 3:7 and repeatedly recycled. After over ten rounds of recycling, the SEBS/PP composites exhibited no significant changes either in tensile strength or in tensile elongation. However, a reduction in hardness, decrease in the temperature of the onset of thermal decomposition, and significant increase in their melt flow index (MFI) values were observed. Notably, X-ray scattering measurement and transmission electron microscopy experiments of the SEBS/PP composites indicated that these changes in hardness and MFI originated from morphological changes of the SEBS/PP composites resulting from thermal degradation of the SEBS triblock copolymers that occurred over multiple rounds of recycling.

Bio-based sustainable composites from hazelnut shell and PP/SEBS blends

“…The characteristic peaks of PP were observed as follows 2950 cm À1 (asymmetrical CH 3 stretching), cm À1 (asymmetrical CH 2 stretching), 43 2838 cm À1 , (CH 3 stretching), 43 1453 cm À1 , cm À1 , (symmetrical CH 3 bending), 1167 cm À1 , 997 cm À1 , 972 cm À1 , 840 cm À1 , cm À1 (wagging C-H, rocking, CH 3 rocking C-H, stretching C-C). [44][45][46] SEBS showed characteristic peaks around 2920 cm À1 and 2851 cm À1 (C-H stretching), [47][48][49][50] 1599, 1460 cm À1 (skeleton deformation vibration of aromatic ring moieties, benzene ring), 1378 cm À1 (-CH vibration of CH 3 ), 42,47,48,51 1028 cm À1 (C-H in-plane-deformation bending of aromatic ring), 48,52 759 cm À1 (aromatic, styrenic-CH bending). 45,53 Since PP and SEBS showed similar peaks between 4000-1600 cm À1 , as given in Figure 8(b) and (c) PP/SEBS blend also showed peaks at 2952 cm À1 , 2918 cm À1 and 2850 cm À1 .…”

Embryonic development and effect of water temperature on hatching of Lophius litulon

“…Two replicate tanks were set in temperature incubators for each of the three egg veils (total 6 tanks for each temperature but 4 tanks at 9ºC by absence of 1B). To cover the range of water temperature that egg veils were collected in previous study ((12-14ºC: Oh and Kim (2015); 14.3ºC: Nakaya et al (2017b);15.9ºC: Mito (1963); 18.2ºC: Kim (1976);19-20ºC: Hoshino et al (2006)), incubation temperatures were maintained at 9, 13, 15, 18, 21 and 24ºC. The pieces of egg veils were acclimated from 18-20°C to the adjacent temperature incubator every 1−2 hours so that the experiment could be started within 12 hours.…”

Electron microscopy analysis of soft materials with freeze‐fracture techniques

“…Above all, it is impossible to directly analyze the deep internal structures surrounded by solvents or membrane layers with SEM or TEM. Various studies have been proposed to improve these analytical limitations, such as the cryo‐method 15,19,29–33 and cryo‐ultra‐microtomy, 34 and freeze‐fracture technique 12,29,35–41 …”

“…Above all, it is impossible to directly analyze the deep internal structures surrounded by solvents or membrane layers with SEM or TEM. Various studies have been proposed to improve these analytical limitations, such as the cryo-method 15,19,[29][30][31][32][33] and cryo-ultra-microtomy, 34 and freeze-fracture technique. 12,29,[35][36][37][38][39][40][41] Among these various techniques, the freeze-fracture technique can significantly contribute to the sample preparation for electron microscopy.…”