Study On Properties And The Ingredient Of Biodegradable Starch-based Onetime-chopsticks

The natural starch has been applied into all fields of industry, and the demands for starch properties in different fields is not same, but the properties of raw starch are not adapted to many application fields, so modifying the structure and properties of physics and chemistry of starch is necessary according to demands, which is adapted to the developments and application of industry.Since eighties of twenty centuries, large quantity of consumptions of onetime plastics tableware and onetime wood-chopsticks have brought about environmental pollution and waste of forest resources. It is urgent to explore a new material which can be degraded in natural environment instead of onetime plastics tableware and onetime wood-chopsticks. According to the above reasons, this report carries out a research about a ingredient of starch-based biodegradable onetime-chopsticks, which is expected to replace the present wood onetime-chopsticks and decrease waste of forest resources.On the basis of many researches of predecessors and from the research of properties of starch and modified starch, the effect of starch granule size on the cross-linking of starch is researched (this research is not reported in internal and external articles), and then the plasticizing modification of starch is also researched. At last, according to the above of research results, the ingredient ratio of starch-based biodegradable onetime-chopsticks and the degradable effect of the tablets are researched. The content and result of experiments are:By the researches of starch cross-linking, the condition of starch cross-linking is determined, which are: using dry cross-linking method, alcohol as the reaction intermedium, (NaPO₃)₆ 0.1% and Na₅P₃O₁₀ 0.01% as the Cross-linked agent, catalyst 10%, Reaction Temperature 45 癈, Reaction Time Ih.In the researches of the starch crashing and effect of modified-starches cross-linking, it is discovered firstly that the properties of crashed-starch in waterproof and oil absorption are improved after crashing starch comparing to raw starch, and it is also discovered firstly that the decrease of difficulties of starch cross-linking follows the enlargement of starch granule.In the research of plasticized starch, glycerine , di-2-ethylhexyl phthalate and butyl stearic are used in the composite plasticizer, the optimal composition isglycerine :di-2-ethylhexyl phthalate: butyl stearic = 2:1:1.After modification and plasticization, the mixture of modified starcluraw starch. Cross-linked agent, plasticizer, reinforcing, stuffing agent and foaming agent is put into the shaping equipment of onetime tableware and is crashed into be the tablets. The tensile strength and elongation at break of degradable tablets with various composition are measured. These studies provide data on the content of the tablets which composed of starch ( raw starch: modified starch=9:l), cotton fiber 3%, stuffing agent 5%, plasticizer 5%, foaming agent 3%. Such composition makes it strong and flexible, which can satisfy the basic demand of mechanics properties of onetime-chopsticks.IR demonstrates the shielding of the hydroxy group, the new structure formation between modified starch, plasticizer and reinforcing agent and the existence of a typical absorption peak of the reinforcing agent. X-ray diffractiongram shows that the crystallinity of the degradable tablets decreases sharply with the formation of more amorphous structure which indicates an increase in the hydrophobic property of the degradable tablets.Biodegradable experiment shows that the starch-based biodegradable material produced by this report has a good biodegradable property. After 30 days and by buried into soil, the material can be completely degraded. For the 80% ingredient of material is starch, it can be used as an addition of the feed after the utilization.