On the Cooccurrence of Demixing and Thermoreversible Gelation of Polymer Solutions. 1. Experimental Observations

L. M. Jelich; S. P. Nunes; E. Paul; B. A. Wolf

doi:10.1021/ma00174a042

On the Cooccurrence of Demixing and Thermoreversible Gelation of Polymer Solutions. 1. Experimental Observations

L. M. Jelich, S. P. Nunes, E. Paul, B. A. Wolf^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

26 Scopus citations

Abstract

The phase diagram of the system 2-propanol/poly(n-butyl methacrylate) (2-POH/PBMA) was determined for two narrowly distributed polymer samples of M_wca. 500000. Demixing curves were measured viscometrically and visually and gelation curves by means of the velocity of a falling body. A third curve (situated within the two-phase region and also resulting from viscosity measurements), which can be related to the aggregation of droplets of the segregated phase upon cooling, is also presented. the evaluation of the gelation conditions for homogeneous solutions according to Eldridge and Ferry yields 37 kj/mol of cross-links for the heat of gelation. Measurements with lower molecular weight PBMA (Af_w8900) confirm the cooccurrence of phase separation and gelation, although the stability of the gels against shear is rather low in this case. the exchange of the 0-solvent 2-POH against ethanol, 1-propanol, 1-butanol, or n-decane does not reveal principal differences.

Original language	English (US)
Pages (from-to)	1943-1947
Number of pages	5
Journal	Macromolecules
Volume	20
Issue number	8
DOIs	https://doi.org/10.1021/ma00174a042
State	Published - Aug 1 1987
Externally published	Yes

ASJC Scopus subject areas

Organic Chemistry
Polymers and Plastics
Inorganic Chemistry
Materials Chemistry

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10.1021/ma00174a042

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title = "On the Cooccurrence of Demixing and Thermoreversible Gelation of Polymer Solutions. 1. Experimental Observations",

abstract = "The phase diagram of the system 2-propanol/poly(n-butyl methacrylate) (2-POH/PBMA) was determined for two narrowly distributed polymer samples of Mwca. 500000. Demixing curves were measured viscometrically and visually and gelation curves by means of the velocity of a falling body. A third curve (situated within the two-phase region and also resulting from viscosity measurements), which can be related to the aggregation of droplets of the segregated phase upon cooling, is also presented. the evaluation of the gelation conditions for homogeneous solutions according to Eldridge and Ferry yields 37 kj/mol of cross-links for the heat of gelation. Measurements with lower molecular weight PBMA (Afw8900) confirm the cooccurrence of phase separation and gelation, although the stability of the gels against shear is rather low in this case. the exchange of the 0-solvent 2-POH against ethanol, 1-propanol, 1-butanol, or n-decane does not reveal principal differences.",

author = "Jelich, {L. M.} and Nunes, {S. P.} and E. Paul and Wolf, {B. A.}",

year = "1987",

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T1 - On the Cooccurrence of Demixing and Thermoreversible Gelation of Polymer Solutions. 1. Experimental Observations

AU - Jelich, L. M.

AU - Nunes, S. P.

AU - Paul, E.

AU - Wolf, B. A.

PY - 1987/8/1

Y1 - 1987/8/1

N2 - The phase diagram of the system 2-propanol/poly(n-butyl methacrylate) (2-POH/PBMA) was determined for two narrowly distributed polymer samples of Mwca. 500000. Demixing curves were measured viscometrically and visually and gelation curves by means of the velocity of a falling body. A third curve (situated within the two-phase region and also resulting from viscosity measurements), which can be related to the aggregation of droplets of the segregated phase upon cooling, is also presented. the evaluation of the gelation conditions for homogeneous solutions according to Eldridge and Ferry yields 37 kj/mol of cross-links for the heat of gelation. Measurements with lower molecular weight PBMA (Afw8900) confirm the cooccurrence of phase separation and gelation, although the stability of the gels against shear is rather low in this case. the exchange of the 0-solvent 2-POH against ethanol, 1-propanol, 1-butanol, or n-decane does not reveal principal differences.

AB - The phase diagram of the system 2-propanol/poly(n-butyl methacrylate) (2-POH/PBMA) was determined for two narrowly distributed polymer samples of Mwca. 500000. Demixing curves were measured viscometrically and visually and gelation curves by means of the velocity of a falling body. A third curve (situated within the two-phase region and also resulting from viscosity measurements), which can be related to the aggregation of droplets of the segregated phase upon cooling, is also presented. the evaluation of the gelation conditions for homogeneous solutions according to Eldridge and Ferry yields 37 kj/mol of cross-links for the heat of gelation. Measurements with lower molecular weight PBMA (Afw8900) confirm the cooccurrence of phase separation and gelation, although the stability of the gels against shear is rather low in this case. the exchange of the 0-solvent 2-POH against ethanol, 1-propanol, 1-butanol, or n-decane does not reveal principal differences.

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DO - 10.1021/ma00174a042

M3 - Article

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JO - Macromolecules

JF - Macromolecules

IS - 8

ER -

On the Cooccurrence of Demixing and Thermoreversible Gelation of Polymer Solutions. 1. Experimental Observations

Abstract

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