Effects of freeze-drying on the glass temperature of cyclic polystyrenes

S. L. Simon; P. Bernazzani; G. B. McKenna

doi:10.1016/j.polymer.2003.10.010

Effects of freeze-drying on the glass temperature of cyclic polystyrenes

S. L. Simon, P. Bernazzani, G. B. McKenna

Chemical Engineering

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29 Scopus citations

Abstract

The calorimetric glass temperature was measured for three cyclic polystyrenes with apparent molecular weights ranging from 4.0×10 ³ to 195.5×10³g/mol for both bulk material and for samples freeze-dried from dilute solution. Freeze-drying from dilute solution was found to reduce the glass temperature by 7-14 K depending on the sample. These T_g depressions are 5-12 K greater than those found previously for freeze-dried linear polystyrene. Annealing at 403.2 and 443.2 K (130 and 170°C) resulted in recovery of the T_g back to the bulk value with the time scales depending on both temperature and the magnitude of the T_g reduction; the low apparent activation energy dependence of the recovery of T_g precludes its being due to viscous flow.

Original language	English
Pages (from-to)	8025-8032
Number of pages	8
Journal	Polymer
Volume	44
Issue number	26
DOIs	https://doi.org/10.1016/j.polymer.2003.10.010
State	Published - Dec 2003

Keywords

Freeze-drying
Glass transition temperature
Polystyrene

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10.1016/j.polymer.2003.10.010

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title = "Effects of freeze-drying on the glass temperature of cyclic polystyrenes",

abstract = "The calorimetric glass temperature was measured for three cyclic polystyrenes with apparent molecular weights ranging from 4.0×10 3 to 195.5×103g/mol for both bulk material and for samples freeze-dried from dilute solution. Freeze-drying from dilute solution was found to reduce the glass temperature by 7-14 K depending on the sample. These Tg depressions are 5-12 K greater than those found previously for freeze-dried linear polystyrene. Annealing at 403.2 and 443.2 K (130 and 170°C) resulted in recovery of the Tg back to the bulk value with the time scales depending on both temperature and the magnitude of the Tg reduction; the low apparent activation energy dependence of the recovery of Tg precludes its being due to viscous flow.",

keywords = "Freeze-drying, Glass transition temperature, Polystyrene",

author = "Simon, {S. L.} and P. Bernazzani and McKenna, {G. B.}",

note = "Funding Information: The authors gratefully acknowledge the National Science Foundation for support of this work through DMR-0304640. We also acknowledge P. Lutz at ICS in Strasbourg for the PS 3050 sample.",

year = "2003",

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doi = "10.1016/j.polymer.2003.10.010",

language = "English",

volume = "44",

pages = "8025--8032",

journal = "Polymer",

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T1 - Effects of freeze-drying on the glass temperature of cyclic polystyrenes

AU - Simon, S. L.

AU - Bernazzani, P.

AU - McKenna, G. B.

N1 - Funding Information: The authors gratefully acknowledge the National Science Foundation for support of this work through DMR-0304640. We also acknowledge P. Lutz at ICS in Strasbourg for the PS 3050 sample.

PY - 2003/12

Y1 - 2003/12

N2 - The calorimetric glass temperature was measured for three cyclic polystyrenes with apparent molecular weights ranging from 4.0×10 3 to 195.5×103g/mol for both bulk material and for samples freeze-dried from dilute solution. Freeze-drying from dilute solution was found to reduce the glass temperature by 7-14 K depending on the sample. These Tg depressions are 5-12 K greater than those found previously for freeze-dried linear polystyrene. Annealing at 403.2 and 443.2 K (130 and 170°C) resulted in recovery of the Tg back to the bulk value with the time scales depending on both temperature and the magnitude of the Tg reduction; the low apparent activation energy dependence of the recovery of Tg precludes its being due to viscous flow.

AB - The calorimetric glass temperature was measured for three cyclic polystyrenes with apparent molecular weights ranging from 4.0×10 3 to 195.5×103g/mol for both bulk material and for samples freeze-dried from dilute solution. Freeze-drying from dilute solution was found to reduce the glass temperature by 7-14 K depending on the sample. These Tg depressions are 5-12 K greater than those found previously for freeze-dried linear polystyrene. Annealing at 403.2 and 443.2 K (130 and 170°C) resulted in recovery of the Tg back to the bulk value with the time scales depending on both temperature and the magnitude of the Tg reduction; the low apparent activation energy dependence of the recovery of Tg precludes its being due to viscous flow.

KW - Freeze-drying

KW - Glass transition temperature

KW - Polystyrene

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U2 - 10.1016/j.polymer.2003.10.010

DO - 10.1016/j.polymer.2003.10.010

M3 - Article

AN - SCOPUS:0842264959

SN - 0032-3861

VL - 44

SP - 8025

EP - 8032

JO - Polymer

JF - Polymer

IS - 26

ER -

Effects of freeze-drying on the glass temperature of cyclic polystyrenes

Abstract

Keywords

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