Solvent-induced crystallization of syndiotactic polystyrene in different liquids—sorption and diffusion phenomena

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

“…The γ form can also be obtained directly by treating the glassy sPS with acetone and then removing the solvent by thermal/vacuum techniques. 12 With CO 2 , glassy sPS is directly transformed into the γ form. Furthermore, on depressurization, CO 2 escapes from the polymer matrix and, thus, no desorption step is required.…”

“…6,7 There are four types of crystalline form, R, , γ, and δ, and two types of mesomorphic form. Forms R and have T 4 conformation (zigzag chains) with an identity period of 5.1 Å, 1,8,9 γ and δ have T 2 G 2 conformation (s(2/1)2 helical chains) with an identity period of 7.7 Å, [10][11][12] while the mesomorphic form can have T 4 or T 2 G 2 conformation depending on the morphology of the starting material used.…”

Effects of polydispersity index and molecular weight on crystallization kinetics of syndiotactic polystyrene (sPS)

“…Corradini et al [2] and De Rosa et al [3] found that different functionality for ␣ and ␤ forms of sPS could be generated with the change of cooling rate. Vittoria et al [4] explored that some kinds of solvents such as dichloromethane, chloroform, and cyclohexane induced new crystalline forms in fibers, modifying * Corresponding author. Tel.…”

Competition between gelation and crystallization in solutions of syndiotactic polystyrene in cis-decalin

“…[1,6,7] Again, this conformation can also lead to two different modifications: the d-modification, formed in all solvents of good quality for polystyrene, and the g-modification, a solvent-free modification formed after heating the d to temperatures around120 8C. [3,6,[8][9][10] Thisconformationcan alsobe formed after structure formation in solutions of Y-solvents. [11] The helix conformation is responsible for the thermoreversible gelation of dilute solutions in good solvents.…”