Investigation into ramie whisker reinforced arylated soy protein composites

Abstract

Whiskers were prepared from ramie fibers and were characterized using atomic force microscopy to evaluate their dimensions. SPI/whiskers composites (SW) were prepared by incorporating different weight contents (wt.%) of the whiskers into soy protein isolate (SPI). Thiodiglycol was used as a plasticizer for the preparation of SW composites. The SW composites were arylated with 2,2-diphenyl-2-hydroxyethanoic acid through the process of “dip-coating” and coded as SW-B. In this paper, the characterization of SW and SW-B composites, such as their morphologies, mechani- cal properties, thermal stability, optical transmittance, and water uptake, are discussed. The results indicated substantial improvement in the water resistance, thermal stability, and the modulus of the SW-B composites after arylation due to the formation of hydrophobic diphenylhydroxymethane (DPHM) microparticles on the surface. This work provides a novel method to increase the water resistance of protein based composites.

Keywords

soy protein / ramie whiskers / water uptake / arylation / composites