In this paper, we investigate the influence of selected reaction parameters on the formation of surface-attached polymer monolayers. The process is based on the use of self-assembled monolayers containing a polymerizable group and the performance of a bulk free radical polymerization reaction ("grafting through polymerization"). To this, methacryl moieties were immobilized on silica gel surfaces via a silane linker. During the polymerization reaction in a conventional way, free polymer is formed in solution. However, every now and then during chain growth also surface-attached monomers become integrated in the polymer chains, leading instantaneously to covalent linking of the growing polymer molecules to the surfaces. As more and more polymer chains become attached, this leads to the formation of a surface-attached polymer layer on the silica surface. Various sets of polymerization reactions were performed and the influence of a variation of temperature, reaction time and concentration of monomer, initiator, and immobilized monomer onto the layer formation are investigated. We propose a model of the layer formation process and the grafting-through process is compared to grafting-to and grafting-from techniques.
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Hoveyda-type catalyst for olefin metathesis was synthesized and covalently attached via an amide bond to four different solid supports. One of these supports was a home-made hybrid silica support, where an ultra-thin copolymer of poly(styrene) and poly(acrylamide) was grafted on. The three other supports were commercially available, namely HypoGel 400, PEGA and Trisoperl. It was demonstrated that the catalysts were active in ring closing metathesis (RCM) reactions as well as in cross metathesis (CM) and ring opening metathesis (ROM) reactions, but the activity of the catalyst was highly dependent on the nature of the support. (c) 2006 Elsevier B.V. All rights reserved.
