Issue 6, 2010
From the journal:

Soft Matter

Silicone foams stabilized by surfactants generated in situ from allyl-functionalized PEG†

Amanda S. Fawcett,a   Helen Y. Sob  and  Michael A. Brook*ab  

* Corresponding authors

a Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, ON, Canada

b School of Biomedical Engineering, McMaster University, 1280 Main Street West, Hamilton, ON, Canada
E-mail: mabrook@mcmaster.ca
Fax: +1 905 522 2509
Tel: +1 905 525 9140

Abstract

Silicone foams normally require the use of agents or chemical reactions that blow gases, and a surfactant for bubble stabilization. We have discovered that the presence of monoallyl-functionalized poly(ethylene glycol) (PEG) leads to large increases in the viscosity of silicone pre-elastomers such that stable foams form with bubbles mostly being generated by coalescence of dissolved gases during the normal degassing process. Although silicone elastomer cure may take up to 24 h for completion, the foams remain stable during this time when appropriate concentrations of allyl-PEG and curing catalyst are used. No traditional surfactant is required, but PEG-modified silicone surfactants are formed in situ by covalent grafting of the PEG to the silicone matrix, leading to the increase in viscosity. The presence of allyl-PEG decreases elastomer cure efficiency, but this is readily overcome, if necessary, to generate more rigid foams by the use of additional platinum catalyst, in which case foaming occurs both due to loss of dissolved gases and to hydrogen evolution. Foam stabilization with appropriate allyl-PEG compounds is a consequence of an initial viscosity increase.

Graphical abstract: Silicone foams stabilized by surfactants generated in situ from allyl-functionalized PEG

About
Cited by
Related
Download options Please wait...

Supplementary files

Article information

DOI
https://doi.org/10.1039/B916413H
Article type
Paper
Submitted
10 Aug 2009
Accepted
23 Dec 2009
First published
18 Jan 2010

Soft Matter, 2010,6, 1229-1237

Permissions

Request permissions

Silicone foams stabilized by surfactants generated in situ from allyl-functionalized PEG

A. S. Fawcett, H. Y. So and M. A. Brook, Soft Matter, 2010, 6, 1229 DOI: 10.1039/B916413H

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements