| alkaline degumming |
Na2CO3
|
strong and effective
action |
possibility of fibroin damage |
(69,80) |
| NaHCO3
|
fast procedure |
decreasing fibers strength |
| Na2HPO4
|
more
cost-effective |
β-sheet structure severely damaged |
| Na3PO4
|
lowering molecular weight |
time consuming |
| Na2[B4O5(OH)4]·8H2O |
a simple approach |
sericin degradation |
| acid degumming |
tartaric acid |
improvement in tensile strength |
slight decrease in dye uptake |
(69,81) |
| lactic acid |
| citric acid |
restricted hydrolysis |
| oxalic acid |
the degumming
bath can be reused |
| malonic acid |
| succinic acid |
| trichloroacetic
acid |
| dichloroacetic acid |
| monochloroacetic acid |
| glacial acetic
acid |
| soap degumming |
marseille, sodium laurate, sodium myristate, sodium
stearate |
whitening and brightening silk |
the degumming bath is not reusable |
(63,82) |
| excellent strength, elasticity |
effluent problems |
| avoids fiber coagulation |
metal ions in water can form insoluble metal soaps on silk |
| enzymatic degumming |
papain |
eliminates uneven dyeing |
simple enzyme deactivation |
(67,71) |
| trypsin |
| proteases |
enhances dye affinity (especially with reactive
dyes) |
expensive |
| completely
removes sericin |
risk of overreaction with fibers |
| environmentally friendly |
not suitable
for large-scale commercial production |
| works
at a moderate pH and temperature |
not efficient in removing
hydrophobic impurities |
| amine
degumming |
methylamine |
providing undamaged
and uniform silk |
not easily applicable to industry |
(63,66) |
| ethylarnine |
fibers |
low degumming rate |
| diethylamine |
water does not affect degumming |
|
| triethylamine |
whitening
and brightening silk |
unpleasant odors |
| marseilles soap |
shorter
processing times |
| lower temperature and less
time required than soap degumming |
| carbon dioxide supercritical fluid degumming |
CO2
|
maintains
the purity of sericin as well |
high costs
and processing demand of high-tech
equipment |
(70) |
| contamination-free |
| reduced amount of wastewater |
| low energy
consumption |
| degumming by urea |
|
high reproducibility |
undesirable degradation of SF |
(83) |
| SS produced
by urea degumming has higher antityrosinase activity
than SS produced by Na2CO3 degumming |
| high temperature
and pressure (autoclaving) |
|
highly efficient |
removing only the outer layer of sericin |
(68,71) |
| no contamination |
effects absorbency and whiteness |
| without contamination |
| cost-effective
method |
| ultrasonication |
|
environmentally friendly |
adding soap, alkali, acid, or enzyme is required |
(69,84) |
| improved
energy efficiency |
| reduced chemical usage |
utilization of electrical energy for acoustic
purposes |
| increasing productivity |
