Selective Enzymatic Grafting by Steric Control

✍ Scribed by Christopher J. Duxbury; David Cummins; Andreas Heise

• Book ID: 102493472
• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 187 KB
• Volume: 28
• Category: Article
• ISSN: 1022-1336
• DOI: 10.1002/marc.200600575

✦ Synopsis

Abstract

Enzymatic grafting of caprolactone was carried out from poly[styrene‐co‐(4‐vinylbenzyl alcohol)] containing 10% hydroxyl functional monomer and compared with the grafting of vinyl acetate. A molecular weight increase due to the grafting of polycaprolactone was observed by size exclusion chromatography. Closer investigation of the grafting density by ^1^H NMR revealed an upper limit to the amount of grafting of about 50–60% of the pendant hydroxyl groups leaving unreacted hydroxyl groups on the polymer backbone available for subsequent reactions. The higher grafting density (95%) obtained with vinyl acetate suggests that this is not due to limited accessibility of the backbone but sterical constrains. Moreover, the grafting action of polycaprolactone seems to be a combination of grafting from by monomer initiation and grafting onto by transesterification of polycaprolactone.

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