A spectroscopic study of phase-transition kinetics in syndiotactic polystyrene

Novel monotitanocene and methylaluminoxane catalyst for syndiospecific polymerization of styrene

“…[27][28][29] In-frared spectroscopy was applied to determine characterization of the sPS crystalline structures. 30 Several infrared bands have been assigned for characterization of the different chain conformations.…”

Thermal‐Induced Crystal/Conformation Transformations in Syndiotactic Polystyrene Films Treated with Different Solvents

“…Similar results have also been described in several previous papers. [3,4] Like sPS/1,1,2,2-tetrachloroethane or other sPS crystal/solvent complexes, [4,[13][14][15][16][17][18] the g ! a 0 transition always occurs at about 200 8C resulting in an obvious exothermic peak that is associated with recrystallization of the melted g-type crystal during the course of DSC scanning upon further heating.…”

“…Recently, subjects of polymorphism of sPS have been widely investigated by using differential scanning calorimetry (DSC), [1,2] X-ray diffraction, [3][4][5] transmission electron microscopy, electron diffraction, [6][7][8] Raman scattering and Fourier-transform infrared spectroscopy (FTIR), [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] etc. There are four known crystals (a-, b-, d-, and g-crystals) in sPS.…”

“…b-type) which can occur upon annealing the solution-cast sPS samples. [3,4,[11][12][13] Infrared absorbance peaks are quite sensitive to intermolecular interactions between polymers and solvents or polymerpolymer and to the ordered states of polymer chains. Thus, the crystal phases and chain conformations in the polymersolvent complexes or polymer crystals can be effectively analyzed using FTIR spectroscopy.…”

“…Thus, the crystal phases and chain conformations in the polymersolvent complexes or polymer crystals can be effectively analyzed using FTIR spectroscopy. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Fourier-transform infrared spectroscopy (FTIR) technique has been commonly and widely used to investigate crystal polymorphism and chain conformations in semicrystalline polymers, [18][19][20][21][22][23] and numerous applications have been demonstrated on investigating the vibrational spectra changes with polymorphism alteration in sPS during various solvent/thermal treatments. By using X-ray diffraction characterization, the preliminary evidences show the different phase transition mechanisms for various polymer-solvent complexes depending on the type of the solvent included in the crystal of the d-type.…”