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Waterborne polyurethane ionomers: structure–property relationships of elastomeric polyurethane ureas and polyurethane ionomers

thesis
posted on 16.11.2018 by Eman Alsaffar
Two groups of water-borne polyurethane ionomers were synthesised using well known methods of synthesis in order to determine the type of elastomers that may be obtained from each method. To begin with, the conventional methods of synthesis for water-borne polyurethane dispersions (WPUDs) in which the process of chain extension occurs in the presence of water was evaluated. This method is restricted to the use of diamines as chain extenders. It was demonstrated that the use of diamines, whether they are primary such as ethylene diamine, or tertiary such as NN’-dimethyl ethylene diamine lead to the formation of polyurethane-urea ionomers that are known for their higher modulus, strength, and lower elongation at break (EAB). The copoly(urethane–urea) ionomers indicated a decreased rate of stress relaxation (RSR). The alternative method of synthesis evaluated was the bulk method of synthesis in which the chain extension process takes place in the bulk. This method allowed the use of diols as chain extenders and resulted in softer elastomers. The polyurethane ionomers obtained by the bulk method of synthesis indicated a high rate of stress relaxation, and, a rapid reduction of load immediately after the application due to their weaker inter-segmental hydrogen bonding interaction. [Continues.]

Funding

SSL International plc.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Materials

Publisher

© Eman Alsaffar

Publisher statement

This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/

Publication date

2006

Notes

A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of the degree of Doctor of Philosophy at Loughborough University.

Language

en

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