Study On Preparation Of Composite Cross-linked Modified Modified Potato Starch

Using potato starch as raw materials,epoxy propane for etherifying agent,sodium trimetaphosphate and acetic anhydride for esterification agents respectively,preparation of potato composite modified starch. Firstly, the process of composite modified starch was studied, and based on this, synthesized compound crosslinked starch.Then its performance and structure is analyzed.Effects of temperature,time,pH and amounts of modifying agent on modified potato starch have been studied.Based on orthogonal experiments,substituted degree as indexes, the optimum conditionsof acetic acid-esterified potato starch are resulted as follows:pH10,amounts of acetic anhydride 7%,time 2.Oh and temperature 30℃for esterification reaction.Sediment volume as indexes,the optimum conditions of cross-linking potato starch are resulted as follows:pHll,time2.0h,amounts of sodium trimetaphosphate 1.5%and temperature 45℃for cross-linking reaction.The single element and orthogonal experiment showed the optimum hydroxypropyl starch reaction condition as follows:propylene oxide additives for 10%,reaction time was 18h,temperature53℃,anhydrous sodium sulfate amount 8%, hydrogen of sodium usage of 1.1% of starch.In each single degeneration, based on experimental results in accordance with hydroxypropyl-crosslinking-acetylation order preparation potato crosslinking hydroxypropyl composite modified starch.Using X-ray diffraction analyzer, Infra-red spectrometris,modified starch particles structure was analysised. X-ray diffraction revealed that after compound modifieds,starch particles crystal shape was not changed,still belong to type B crystal structure. The infrared spectrum union chemistry analytical table has proven the compound modified reaction process occurrence. The results show that potato starch, potato crosslinking hydroxypropyl starch,potato crosslinking acetylation starch comparison,composite modified starch pasting temperature of reduced,free-thaw stability,viscositeand acid proof,transparency and anti-aging sex increased significantly.