Solution properties of a hydrophobically modified polymer

Research output: ThesisDoctoral Thesis (compilation)

Standard

Solution properties of a hydrophobically modified polymer. / Thuresson, Krister.

Physical Chemistry 1, Lund University, 1996. 35 p.

Research output: ThesisDoctoral Thesis (compilation)

Harvard

Thuresson, K 1996, 'Solution properties of a hydrophobically modified polymer', Doctor, Physical Chemistry.

APA

Thuresson, K. (1996). Solution properties of a hydrophobically modified polymer. Physical Chemistry 1, Lund University.

CBE

Thuresson K. 1996. Solution properties of a hydrophobically modified polymer. Physical Chemistry 1, Lund University. 35 p.

MLA

Thuresson, Krister Solution properties of a hydrophobically modified polymer Physical Chemistry 1, Lund University. 1996.

Vancouver

Thuresson K. Solution properties of a hydrophobically modified polymer. Physical Chemistry 1, Lund University, 1996. 35 p.

Author

Thuresson, Krister. / Solution properties of a hydrophobically modified polymer. Physical Chemistry 1, Lund University, 1996. 35 p.

RIS

TY - THES

T1 - Solution properties of a hydrophobically modified polymer

AU - Thuresson, Krister

N1 - Defence details Date: 1996-05-25 Time: 10:15 Place: lecture hall C, Chemical Center, Lund External reviewer(s) Name: Leibler, Ludwik Title: [unknown] Affiliation: Elf-Atochem, UMR CAL, 95 rue Danton, B. P. 108, 92303 Levallois-Perret cedex, France ---

PY - 1996

Y1 - 1996

N2 - The influence of hydrophobic modification on solution properties of water-soluble polymers in the semi-dilute regime have been studied. The nonionic ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue (HM-EHEC) are used as model substances. Interactions between the polymer molecules in solution and a third component are investigated, and in particular the influence of the surfactant sodium dodecylsulfate (SDS). The polymer/SDS complex formation is investigated by using several techniques (phase behaviour, rheology, calorimetry, DS- sensitive electrode, NMR, and light scattering and fluorescence techniques). This combination of methods gives thermodynamic information on the complex formation, as well as information about the dynamics of the polymer/surfactant complex. In a binary, semi-dilute, HM-EHEC solution the hydrophobic tails associate in clusters with an average of ten tails. These 'pre-formed' micelles act as nucleation sites for other molecules that contain hydrophobic moieties. The number of mixed micelles, and the strengths of the inter polymeric bonds which they give rise to, control both microscopic properties (as chain motions) and macroscopic behaviour (as rheology and phase behaviour). Experimental phase studies with hexanol as a third component were compared with model calculations in a modified Flory-Huggins approach. By assuming that hydrophobic modification causes enhanced association with the polymer semi-quantitative agreement was found. The associative phase separation that is usually observed in mixtures of two oppositely charged polyelectrolytes is effectively prevented by hydrophobic modification of both polyelectrolytes; a highly viscous phase is formed.

AB - The influence of hydrophobic modification on solution properties of water-soluble polymers in the semi-dilute regime have been studied. The nonionic ethyl(hydroxyethyl)cellulose (EHEC) and its hydrophobically modified analogue (HM-EHEC) are used as model substances. Interactions between the polymer molecules in solution and a third component are investigated, and in particular the influence of the surfactant sodium dodecylsulfate (SDS). The polymer/SDS complex formation is investigated by using several techniques (phase behaviour, rheology, calorimetry, DS- sensitive electrode, NMR, and light scattering and fluorescence techniques). This combination of methods gives thermodynamic information on the complex formation, as well as information about the dynamics of the polymer/surfactant complex. In a binary, semi-dilute, HM-EHEC solution the hydrophobic tails associate in clusters with an average of ten tails. These 'pre-formed' micelles act as nucleation sites for other molecules that contain hydrophobic moieties. The number of mixed micelles, and the strengths of the inter polymeric bonds which they give rise to, control both microscopic properties (as chain motions) and macroscopic behaviour (as rheology and phase behaviour). Experimental phase studies with hexanol as a third component were compared with model calculations in a modified Flory-Huggins approach. By assuming that hydrophobic modification causes enhanced association with the polymer semi-quantitative agreement was found. The associative phase separation that is usually observed in mixtures of two oppositely charged polyelectrolytes is effectively prevented by hydrophobic modification of both polyelectrolytes; a highly viscous phase is formed.

KW - sodium dodecylsulfate

KW - surfactants

KW - fluorescence

KW - light scattering

KW - NMR

KW - rheology

KW - cloud point

KW - phase behaviour

KW - polyelectrolytes

KW - ethyl(hydroxyethyl)cellulose

KW - hydrophobically modified

KW - water soluble polymers

KW - aggregation number

KW - association

KW - Physical chemistry

KW - Fysikalisk kemi

M3 - Doctoral Thesis (compilation)

SN - ISBN91-628-2088-5

PB - Physical Chemistry 1, Lund University

ER -