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Thermal and mechanical properties and water absorption of guanidine hydrochloride‐modified soy protein (11s)
Author(s) -
Zhong Z. K.,
Sun X. S.
Publication year - 2000
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/1097-4628(20001031)78:5<1063::aid-app150>3.0.co;2-9
Subject(s) - differential scanning calorimetry , absorption of water , guanidine , materials science , glass transition , dynamic mechanical analysis , plasticizer , absorption (acoustics) , chemical engineering , polymer chemistry , chemistry , composite material , polymer , organic chemistry , physics , engineering , thermodynamics
Abstract Thermal and mechanical properties and water absorption of guanidine hydrochloride (GuHCl)‐modified 11S soy protein and molded plastics made from it were studied using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), mechanical tests, and scanning electron microscopy (SEM). The DSC results showed that the denaturation temperature of GuHCl‐modified 11S solutions was higher than that of the control sample and the high concentration GuHCl completely denatured 11S. Nonfreezing water of the modified 11S solution exhibited a minimum value at 0.9 M GuHCl. Both DSC and DMA results showed that GuHCl was a plasticizer of 11S and the glass transition temperature of modified 11S plastics decreased with increasing GuHCl concentration. Both the stress and strain of modified 11S plastics reached their highest values at a 0.9 GuHCl concentration. The SEM observations supported these results. A water‐absorption test showed an improvement in the water resistance of 11S plastics with GuHCl modification. The water absorption had a minimum value at 0.9 M GuHCl. The interaction between GuHCl molecules and 11S protein was found to have important effects on the thermal and mechanical properties and the water absorption of 11S plastics. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1063–1070, 2000