Deformation and molecular orientation in films of metallocene polypropylene, ethylene–butylene rubber, and their 80/20 (w/w) blend revealed by the simultaneous kinetic measurement of microscopic infrared dichroism, macroscopic stress, and mesoscale strain

Abstract

Simultaneous kinetic measurement of microscopic infrared dichroism, macroscopic stress, and mesoscale strain was used to study the deformation mechanisms of metallocene polypropylene (MPP), ethylene-butylene rubber (EBR), and their blend (MPP/EBR ¼ 80/20 w/w). As with pure MPP, the molecular orientation in the blend is dominated by the necking of the isotactic polypropylene matrix. During the necking passage through the mesoscale sampling area, the molecular orientation of the polypropylene matrix in the blend is smaller than that in the pure polypropylene film at the same level of mesoscale strain. However, the orientation of the EBR dispersed phase in the blend is larger than that in the pure EBR film. This may result from the partial miscibility of the two ingredients in the amorphous phases and their resultant strong interfacial interaction. The large stress supported by the MPP matrix extends to the island of the EBR domain and leads to its large deformation. V V C 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1520-1531, 2005

Enhanced thermal conductivity of PE/BN composites through controlling crystallization behavior of PE matrix

“…Figure a shows the temperature‐dependent IR spectra of the PE/BN composites with 30 wt% BN (150–80°C) in the region 700–740 cm −1 . The band around 720 cm −1 was assigned to CH rocking vibration of the CH 2  in PE molecular chain , and it included crystalline region and amorphous region. The band around 729 cm −1 was assigned to CH rocking vibration of the CH 2  in the crystalline region.…”

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

“…The IR spectrum of SEBS is the overlapping of S block (atactic polystyrene) and EB block (poly-(ethylene-co-1-butene)) IR spectra (not displayed here). According to the literature, [37][38][39][40][41][42][43][44][45][46][47] the bands assignment of SEBS spectrum are summarized in Table 1.…”

“…Generally, the weak crystalline of -(CH 2 -CH 2 )n of EB block should exist in continuous phase (soft block EB), and therefore it has no relation with disperse phase (hard block S). However, at 48 °C, the correlation intensity peaks at 700 cm -1 [38][39][40] C-H asymmetry stretching, -CH3 2923 37 C-H asymmetry stretching, -CH2-C-H asymmetry stretching of fundamental chain, -CH2-2852 37 C-H symmetry stretching, -CH2-C-H symmetry stretching of fundamental chain, -CH2-1600 37 V9B(B1) framework vibration of the side benzene ring 1594 47 overtone or combination vibration of the side benzene ring 1585 37 V9A(A1) framework vibration of the side benzene ring 1575 47 overtone or combination vibration of the side benzene ring 1568 47 overtone or combination vibration of the side benzene ring 1461 [37][38][39][40] C-H bending, -CH2-1378 [38][39][40] C-H bending, -CH3 1263 [43][44][45][46] vibration of the helical structure in crystals 1195 37 V8A(A1) vibration of the side benzene ring 1157 37 V′15(B1) vibration of the side benzene ring 762 37 dC-H bending vibration of side benzene ring 721 37,41,42 C-H rocking, -CH2-700 37 dC-H bending vibration of side benzene ring and 762 cm -1 assigned to the dC-H bending vibration of the side benzene ring of S block appear simultaneously. It can be speculated that a few of the polystyrene chain segments surround some weak crystalline domain of EB block.…”

Separation of the molecular motion from different components or phases using projection moving-window 2D correlation FTIR spectroscopy for multiphase and multicomponent polymers

“…The bands at 720 cm À1 , which is the CH 2 rocking of the ethylene units of the EB component, is the characteristic bands of the ethylene units. 45,48,52 This bands does not overlap with any bands of the PS component. The peak intensity of 720 cm À1 gradually weakened to disappear when the temperature increases from 30 C to 175 C. Thus, the intensity variation at 720 cm À1 indicates the microcrystalline melting of the ethylene units of the EB component.…”

“…The projection matrix (or vector) must be determined to extract the molecular motion of CH 2 groups of the ethylene units. According to the literature, 45,[48][49][50][51][52] the bands at 1462, 1453, and 720 cm À1 are attributed to CH 2 in 1630 cm À1 to 630 cm À1 region. The bands at 1462 and 1453 cm À1 , which still show serious overlapping, are attributed to the CH 2 bending vibrations.…”