Polymorphism and phase transitions upon annealing in solvent-cast vs quenched syndiotactic polystyrene and its blends with atactic polystyren

Ya Sen Sun, E. M. Woo, Ming Chien Wu, Rong Ming Ho

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

The crystal polymorphism and phase transition mechanisms upon specific annealing schemes imposed on either neat syndiotactic polystyrene (sPS) or its miscible blends with atactic polystyrene (aPS) were examined using Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WAXD). The neat sPS or blends were made in such ways that they started as either initially an amorphous/quenched material or solvent-treated to contain initially some trace crystalline γ-form. Cold crystallization imposed on the initially quenched/amorphous sPS led to the random-coil chains being crystallized into initially a mesomorphic form and subsequently into a more perfect crystalline α-form. IR spectroscopy characterization confirmed a series of structural changes with respect to the annealing temperature imposed on initially quenched/amorphous sPS and revealed a transition from a mesomorphic form to a crystalline α′-form via a nucleation and growth process. Conversely, cold crystallization imposed on the initially quenched miscible blends (sPS/aPS) did not involve a mesomorphic form but developed directly into a crystalline α- and/or β-form upon further annealing to higher temperatures. However, the transition behavior was similar between the solvent-cast neat sPS and solvent-cast sPS/aPS blend upon annealing to higher temperatures. The solvent (1,1,2,2-tetrachloroethane)-induced γ-form in the sPS/aPS blend or neat sPS samples, upon heating to temperatures above 200°C, both exhibited crystal reorganization of the melted crystalline γ-form originally present, which led to formation of the crystalline α′-form. The mechanisms and causes for the different routes of phase transitions in neat sPS or its miscible blends were discussed and analyzed.

Original languageEnglish
Pages (from-to)8415-8425
Number of pages11
JournalMacromolecules
Volume36
Issue number22
DOIs
Publication statusPublished - 2003 Nov 4

Fingerprint

Polystyrenes
Polymorphism
Phase transitions
Annealing
Crystalline materials
Crystallization
Temperature
Crystals
Infrared spectroscopy
Fourier transforms
Nucleation

All Science Journal Classification (ASJC) codes

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

Cite this

@article{f87d7b6375e54abeb69caa8678d89f29,
title = "Polymorphism and phase transitions upon annealing in solvent-cast vs quenched syndiotactic polystyrene and its blends with atactic polystyren",
abstract = "The crystal polymorphism and phase transition mechanisms upon specific annealing schemes imposed on either neat syndiotactic polystyrene (sPS) or its miscible blends with atactic polystyrene (aPS) were examined using Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WAXD). The neat sPS or blends were made in such ways that they started as either initially an amorphous/quenched material or solvent-treated to contain initially some trace crystalline γ-form. Cold crystallization imposed on the initially quenched/amorphous sPS led to the random-coil chains being crystallized into initially a mesomorphic form and subsequently into a more perfect crystalline α-form. IR spectroscopy characterization confirmed a series of structural changes with respect to the annealing temperature imposed on initially quenched/amorphous sPS and revealed a transition from a mesomorphic form to a crystalline α′-form via a nucleation and growth process. Conversely, cold crystallization imposed on the initially quenched miscible blends (sPS/aPS) did not involve a mesomorphic form but developed directly into a crystalline α- and/or β-form upon further annealing to higher temperatures. However, the transition behavior was similar between the solvent-cast neat sPS and solvent-cast sPS/aPS blend upon annealing to higher temperatures. The solvent (1,1,2,2-tetrachloroethane)-induced γ-form in the sPS/aPS blend or neat sPS samples, upon heating to temperatures above 200°C, both exhibited crystal reorganization of the melted crystalline γ-form originally present, which led to formation of the crystalline α′-form. The mechanisms and causes for the different routes of phase transitions in neat sPS or its miscible blends were discussed and analyzed.",
author = "Sun, {Ya Sen} and Woo, {E. M.} and Wu, {Ming Chien} and Ho, {Rong Ming}",
year = "2003",
month = "11",
day = "4",
doi = "10.1021/ma034290q",
language = "English",
volume = "36",
pages = "8415--8425",
journal = "Macromolecules",
issn = "0024-9297",
publisher = "American Chemical Society",
number = "22",

}

Polymorphism and phase transitions upon annealing in solvent-cast vs quenched syndiotactic polystyrene and its blends with atactic polystyren. / Sun, Ya Sen; Woo, E. M.; Wu, Ming Chien; Ho, Rong Ming.

In: Macromolecules, Vol. 36, No. 22, 04.11.2003, p. 8415-8425.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Polymorphism and phase transitions upon annealing in solvent-cast vs quenched syndiotactic polystyrene and its blends with atactic polystyren

AU - Sun, Ya Sen

AU - Woo, E. M.

AU - Wu, Ming Chien

AU - Ho, Rong Ming

PY - 2003/11/4

Y1 - 2003/11/4

N2 - The crystal polymorphism and phase transition mechanisms upon specific annealing schemes imposed on either neat syndiotactic polystyrene (sPS) or its miscible blends with atactic polystyrene (aPS) were examined using Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WAXD). The neat sPS or blends were made in such ways that they started as either initially an amorphous/quenched material or solvent-treated to contain initially some trace crystalline γ-form. Cold crystallization imposed on the initially quenched/amorphous sPS led to the random-coil chains being crystallized into initially a mesomorphic form and subsequently into a more perfect crystalline α-form. IR spectroscopy characterization confirmed a series of structural changes with respect to the annealing temperature imposed on initially quenched/amorphous sPS and revealed a transition from a mesomorphic form to a crystalline α′-form via a nucleation and growth process. Conversely, cold crystallization imposed on the initially quenched miscible blends (sPS/aPS) did not involve a mesomorphic form but developed directly into a crystalline α- and/or β-form upon further annealing to higher temperatures. However, the transition behavior was similar between the solvent-cast neat sPS and solvent-cast sPS/aPS blend upon annealing to higher temperatures. The solvent (1,1,2,2-tetrachloroethane)-induced γ-form in the sPS/aPS blend or neat sPS samples, upon heating to temperatures above 200°C, both exhibited crystal reorganization of the melted crystalline γ-form originally present, which led to formation of the crystalline α′-form. The mechanisms and causes for the different routes of phase transitions in neat sPS or its miscible blends were discussed and analyzed.

AB - The crystal polymorphism and phase transition mechanisms upon specific annealing schemes imposed on either neat syndiotactic polystyrene (sPS) or its miscible blends with atactic polystyrene (aPS) were examined using Fourier transform infrared (FT-IR) and wide-angle X-ray diffraction (WAXD). The neat sPS or blends were made in such ways that they started as either initially an amorphous/quenched material or solvent-treated to contain initially some trace crystalline γ-form. Cold crystallization imposed on the initially quenched/amorphous sPS led to the random-coil chains being crystallized into initially a mesomorphic form and subsequently into a more perfect crystalline α-form. IR spectroscopy characterization confirmed a series of structural changes with respect to the annealing temperature imposed on initially quenched/amorphous sPS and revealed a transition from a mesomorphic form to a crystalline α′-form via a nucleation and growth process. Conversely, cold crystallization imposed on the initially quenched miscible blends (sPS/aPS) did not involve a mesomorphic form but developed directly into a crystalline α- and/or β-form upon further annealing to higher temperatures. However, the transition behavior was similar between the solvent-cast neat sPS and solvent-cast sPS/aPS blend upon annealing to higher temperatures. The solvent (1,1,2,2-tetrachloroethane)-induced γ-form in the sPS/aPS blend or neat sPS samples, upon heating to temperatures above 200°C, both exhibited crystal reorganization of the melted crystalline γ-form originally present, which led to formation of the crystalline α′-form. The mechanisms and causes for the different routes of phase transitions in neat sPS or its miscible blends were discussed and analyzed.

UR - http://www.scopus.com/inward/record.url?scp=0344549721&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0344549721&partnerID=8YFLogxK

U2 - 10.1021/ma034290q

DO - 10.1021/ma034290q

M3 - Article

AN - SCOPUS:0344549721

VL - 36

SP - 8415

EP - 8425

JO - Macromolecules

JF - Macromolecules

SN - 0024-9297

IS - 22

ER -