Synthesis and photocuring of cinnamoyl trehalose esters

Abstract

A trehalose cinnamoyl ester (TC) was synthesized from trehalose and cinnamoyl chloride in dimethylformamide (DMF) in the presence of triethylamine and 4-(N,N-dimethylamino)pyridine. The product was characterized by 1H NMR spectroscopy to reveal that the reaction proceeded. Two different types of TCs were synthesized by changing the feed ratio of cinnamoyl chloride to trehalose. When the feed ratio of cinnamoyl chloride to trehalose was 8 (TC8), the degree of substitution (DS) was 8.0, while it was 4.2 when the feed ratio was 4 (TC4). Photocuring was confirmed by observing changes in UV absorption spectrum and FT Infrared (IR) spectrum. After 5 min of UV irradiation, solubility in chloroform significantly decreased. A transparent thin coating film of TC was easily prepared by casting from a chloroform solution on a Petri dish and UV irradiation was carried out over a simple photomask. After TC within the non-irradiated region was removed by flash soaking with chloroform, the shape of the photomask appeared. A scanning electron microscope (SEM) measurement revealed that the surface of the photocured coating film was smooth and that the edge of the photocured TC had a characteristic feature. Biodegradation of the photocured TC and non-irradiated TC was examined by the biochemical ougen demand (BOD) method using activated sludge. Copyright © 2007 John Wiley & Sons, Ltd.