Change search
ReferencesLink to record
Permanent link

Direct link
Controlled destruction of residual crosslinker in a silicone elastomer for drug delivery
KTH, Superseded Departments, Polymer Technology.
2002 (English)In: Journal of Applied Polymer Science, ISSN 0021-8995, E-ISSN 1097-4628, Vol. 84, no 12, 2254-2264 p.Article in journal (Refereed) Published
Abstract [en]

In drug delivery systems that use silicone elastomers as a diffusion matrix for the active drug, it is common to crosslink the material by the hydrosilylation reaction. In this platinum-catalyzed reaction, vinyl groups on a polymer add to the methyl siloxane hydride (MHS) groups on a low molecular mass crosslinker. With an excess of crosslinker, a fast curing is achieved and a fully crosslinked material is formed. Unreacted MHS groups were shown to remain in the elastomer after curing because of the excess crosslinker. In this work, a simple procedure was developed to eliminate the unreacted MHS groups from the final product. We found that storage of the product at +40degrees and 75% relative humidity for a few weeks will effectively destroy the residual MHS groups in the elastomer. The effects of varying levels of humidity, oxygen, and temperature on this postcuring procedure were studied. The amount of MHS groups was measured with NMR and IR spectroscopy. We also found that the hardness of the material increased by approximately 25% as a consequence of this postcuring treatment. This increase is probably due to a secondary crosslinking reaction between MHS and silanol groups. Heat treatment at higher temperatures led to an even further increase in the hardness and compression modulus. Because no MHS groups remained in the elastomer when this heat treatment was started, it is apparent that another secondary crosslinking reaction is occurring, probably silanol condensation.

Place, publisher, year, edition, pages
2002. Vol. 84, no 12, 2254-2264 p.
Keyword [en]
poly(dimethyl siloxane), crosslinker, methyl hydrogen siloxane, silicone hydride, postcuring, aging, humidity, cure
URN: urn:nbn:se:kth:diva-21424DOI: 10.1002/app.10481ISI: 000174667100015OAI: diva2:340122
QC 20100525Available from: 2010-08-10 Created: 2010-08-10Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Albertsson, Ann-Christine
By organisation
Polymer Technology
In the same journal
Journal of Applied Polymer Science

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 23 hits
ReferencesLink to record
Permanent link

Direct link