Sum frequency generation vibrational spectroscopic studies on a silane adhesion-promoting mixture at a polymer interface

Cheryl L Loch; Dongchan Ahn; Zhan Chen

doi:10.1021/jp055377b

Sum frequency generation vibrational spectroscopic studies on a silane adhesion-promoting mixture at a polymer interface

J Phys Chem B. 2006 Jan 19;110(2):914-8. doi: 10.1021/jp055377b.

Authors

Cheryl L Loch¹, Dongchan Ahn, Zhan Chen

Affiliation

¹ Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA.

PMID: 16471623
DOI: 10.1021/jp055377b

Abstract

Sum frequency generation (SFG) vibrational spectroscopy was used to probe the interface between poly(ethylene terephthalate) with deuterated ethylene glycol subunits (d4-PET) and a silane adhesion-promoting mixture (SAPM) comprised of (3-glycidoxypropyl)trimethoxysilane (gamma-GPS) and a methylvinylsiloxanol (MVS). Such a mixture has been found to improve the adhesion of an addition-curing silicone elastomer to a range of plastic and metal substrates. Our results demonstrated that at the interface between d4-PET and a SAPM with a gamma-GPS/MVS ratio of 1:1 (w/w), the silane molecules not only segregated to the interface but also the methoxy headgroups likely adopted a greater net orientational order along the surface normal than at the d4-PET/gamma-GPS interface. The effects of varying the silane/siloxane ratio and using different siloxane oligomers on interfacial structures were also examined. This study provides unique molecular-level insights into the prerequisite conditions for adhesion of curable silicone adhesives.