Research Of Amylose Plasticized By Molecular Dynamics Simulation

Starch is renewable green resources owing to its abundance, wide varieties, low costand complete biodegradability. However, the application and development of starchdegradable plastic has been affected by its defects in heat processing. As a result, more andmore scientists began to pay close attention to the starch thermal plasticizing. Althoughthere are several methods to plasticize starch, adding plasticizer is more economical andeffective to improve the processability of starch. In this paper, by means of the moleculardynamics simulation, IR analysis and torque analysis technology, the amylose starchplasticized by alcohols and several plasticizers with different ratio was studied in detail. Theresults showed that:(1) The molecular simulation software (Materials Studio) can perfectly simulate thestructure of amylase, and the simulation results showed that there are hydrogen bondinginteraction between amylose.(2) The research on the amylose plasticized by different small molecule of alcohols bymolecular dynamics simulation and experiments showed that: alcohol with the same numberof hydroxyl groups and fewer number of carbon atoms has stronger plasticizing capacity inamylose; alcohol with the same number of carbon atoms and more hydroxyl groups hasstronger plasticizing capacity in amylose. Comprehensive results showed that theamylase-plasticizing capacity of alcohols as follows: glycol> glycerol> ethanol>propylene glycol> xylitol.(3) The research on the amylose plasticized by different types of plasticizer bymolecular dynamics simulation and experiments showed that: the easier to the formation ofhydrogen bonding between plasticizer and amylose, the stronger plasticizing capacity inamylose, the plasticizer has the stronger diffusion ability, the plasticizer is more easily getinto the amylose, the greater probability of interaction between amylose molecules andplasticizer, the stronger plasticizing capacity in amylose. Comprehensive results showed thatthe plasticizing capacity of several plasticizer as follows:Melamine<PVA<DMSO<Ethylene Glycol<Urea.(4) The research on the amylose plasticized by urea at different proportions bymolecular dynamics simulation and experiments showed that the plasticizing capacity wasfirst enhanced and then weakened with the increasing of ratio of the plasticizer. The plasticizing capacity of the three concentrations of urea is:30%>20%>40%.(5) The results from molecular dynamics simulation and experiments are basicallyidentical. Therefore, the application of molecular dynamics simulation to study the amyloseplasticized by plasticizer is feasible.