Solvent‐induced polymorphism in syndiotactic polystyrene

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

“…[3][4][5] Insolutionorafterabsorptionof solvent, the T 2 G 2 helix conformation can be formed. [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.…”

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

“…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.…”

The role of molecular mechanics in the prediction of the chain conformation of polymers in the crystalline state: Syndiotactic polymers

“…Helical symmetries s(M/N)2 have been found in some crystalline forms of sPP [9][10][11] , sPS [12][13][14][15][16] , sPB 17) , syndiotactic poly(p-methylstyrene) 18) , syndiotactic poly(4-methyl-1-pentene) 19) and syndiotactic 1,2-poly(4-methyl-1,3-pentadiene) 20) . The particular case of M/N = 2/1 is the most common one and in many cases the s(2/1)2 is the only symmetry found.…”