Study On Chemical Modification And Plastification Of Soy Protein Isolate

In this paper, the influence of chemical modification on soy protein islate(SPI) was studied, also researched the plasticizer and forming process on modified material.Dimethyldichlorosilane, sodium hydroxide, urea, thiourea and acetic acid, propionic acid, sodium sulfite deoxidization, zinc sulfate, silica, dodecylbenzenesulfonic acid, sodium dodecyl sulfate, sodium dodecyl sulfonic acid sodium were used for chemical modification. The plasticization of glycerol and caprolactam, ethyl amide, polyethylene glycol (PEG) series, sorbitol, epoxy soybean oil on modified protein materials were also studied.The various forming method and process conditions were explored.The means of infrared spectrum of modified soybean protein isolated was also investigated. Thermal properties, mechanical properties, theological properties, water resistant properties and surface morphology, etc., were texted. The results showed that alkali ccould effectively cut off protein molecules of long chain structure, raised protein molecules processing liquidity; urea and thiourea could make protein fully degeneration, thus made the curl of protein long-chain extend to hydrophobic exposure to water resistance groups of improvement; dimethyldichlorosilane ccould react off hydrophilic groups also helpful to improve the water resistance; surfactant series of products had strong degeneration effect on protein, the protein long-chain stretch after rule arrangement could significantly enhance the mechanical properties of materials. The results also showed that glycerin, polyethylene glycol200, polyethylene glycol300, polyethylene glycol400, sorbitol small molecules such as multiple alcohols and caprolactam, ethyl amide etc amide of chemical modification of the protein had good plasticization, which could significantly improve the performance of various materials, polyethylene glycol (PEG) series of silane modificated materials increase comprehensive effect was better than other plastic plasticizer, caprolactam and glycerin had good plasticization on the modified protein and improved other performances. The processing technology research on soybean protein material showed, the best mixing time was5minutes for Dimethyldichlorosilane modified protein and3min for surfactant modified protein. The suitable temperature was120℃for Dimethyldichlorosilane modified protein, and140℃for surfactant modified protein. Hot pressing molding temperature was120℃for Dimethyldichlorosilane modified protein and140℃for surfactant series, the best hot-pressing time was15minutes.