Flax Fiber Reinforced Arylated Soy Protein Isolate

摘要

Soy protein plastics prepared by solution casting method can achieve the modulus of 20-50 MPa while that of soy protein plastics prepared by compression molding ranges from 50-100 MPa at high relative humidity (50 to 75% RH). On the other hand, modulus of natural fiber bundle varies between 650 and 1050 MPa. So the modulus of soy protein based plastics is relatively very less compared to that of natural fibers. It has been recently reported that arylation of soy protein in presence of 2,2-diphenyl-2-hydroxyethanoic acid (DPHEAc) leads to protein material with very high modulus in the range of 800 to 1100 MPa even at high relative humidity (50 to 75% RH). Water-mediated arylation by dip coating method is responsible for the high modulus of soy protein materials. Here, we are reporting damage-sensitive composites prepared from arylated soy protein (as brittle-matrix) and flax fabric. Bio-composites were successfully prepared by reinforcing soy protein isolate with different weight fractions (0.2 to 0.4) of woven flax fabric. Flax fabric reinforced soy protein isolate based composites were then arylated with 2, 2-diphenyl-2-hydroxyethanoic acid (DPHEAc) for 4 h to get arylated bio-composites. Characterizations of the arylated and non-arylated bio-composites were performed by thermo gravimetric analysis. Results indicated that arylated soy protein based composites displayed mechanical behaviour like brittle-matrix composites that differentiated them from non-arylated soy protein based composites which displayed mechanical behaviour like polymermatrix composites. Scanning electron microscopy was also carried out to understand the nature of cracks and fractures suffered by the arylated soy protein composites when subjected to tensile tests.