On the crystal structure of the orthorhombic form of syndiotactic polystyrene

Effect of Compressed CO2 on Phase Transitions and Polymorphism in Syndiotactic Polystyrene

“…9,15 A small peak at 2θ ) 28.2°is present in the sample treated at 210°C but absent in that treated at 240°C and, based on the results shown in Figure 8, can be attributed to the presence of a small amount of the γ form. In going from 210 to 240°C, the fine structure of the form develops, as indicated by the appearance of a peak at 2θ ) 21.3°, 15 and its crystallinity also increases, as indicated by the increase in diffraction intensity. However, the form obtained still corresponds to the low-order phase ′; the more ordered phase ′′ is characterized by additional peaks at 2θ ) 13.6 and 15.8°.…”

“…9,13,14 The form can be obtained by slow cooling from the melt or by casting from a solution in o-dichlorobenzene at elevated temperatures. 15 Depending on the solvent type, crystal form δ or γ is obtained when amorphous sPS is immersed in liquid solvent and then dried under vacuum or directly exposed to solvent vapor. [16][17][18] Generally, the δ form contains solvent molecules entrapped in the crystal structure whereas the γ form is free of solvent.…”

Absorption Kinetics of Phenol into Different Size Nanopores Present in Syndiotactic Polystyrene and Poly (p-methylstyrene)

“…Then the number of phenol molecules incorporated in the pores of sPS and sPPMS was calculated by eq. (9). The crystallinity of cast-crystallized sPS was 0.52 after soaking in phenol solution.…”

“…It has been reported that there are five crystalline modifications. The [4][5][6][7][8] and [9,10] forms consist of a planar zigzag chain with period of 5.1 Å, whereas the [11][12][13], [14][15][16][17], and [18][19][20] forms adopt a helical structure with a trans-trans-gauche-gauche (ttgg) conformation, having a period of 7.7 Å. The crystal with an all-trans conformation is a thermally stabilized form induced above about 180 °C and its high melting temperature around 270 °C is expected to be useful as an engineering plastic.…”

Temperature Induced Structural Changes in Syndiotactic Polystyrene/cis-Decalin Systems

“…[1][2][3][4][5][6][7][8][9] The polymer chain backbone can adopt two different conformations: an all-trans planar zigzag (T 4 ) and a helical structure (T 2 G 2 ). These two different conformations give rise to four crystal modifications.…”