The Preparation And Properties Of Oxidized Starch And Its Adhesive

The research first synthesizes oxidized starch which preparation procedure uses potato starch as raw material, ferrous sulfate as catalyst, and chooses hydrogen peroxide as oxidizer. And then, adds base for gelatinization, crosslinking agent for crosslinking modification. After the mixture cooling down, diluting agent, plasticizer, defoaming agents, etc. have been added consecutively. Finally, an environment-friendly, low cost, and premium properties'starch-base adhesive for corrugated fiberboard was produced. In this paper, the study is mainly about the preparation and characterization of oxidized starch; the formula and preparation technology of adhesive, as well as its performance; besides, quick-drying modification of starch adhesive is also part of the study.Firstly, the research focuses on the preparative of potato starch by hydrogen peroxide, Oxidized starch was characterized by IR,XRD and SEM.The temperature of reaction; the dosage of hydrogen peroxide; the dosage of catalyst; the reaction time are the factors of effect on oxidized starch's hydroxyl content and carbonyl group index, and these were studied via single-factor experiment. The results show that the xoidation-reduction system of H2O2-FeSO4 is hard to break up the cyrstalline phase of starch,and the oxidation reaction occur major in amorphous region. starch charge 30g, oxidizer (30% H2O2)charge 1.6mL, catalyst (FeSO4)charge 0.1 g, reaction time 60min, reaction temperature 35℃, the degree of oxidation of starch and the content of cabroxyl group as well as cabronyl group were maxlmum.Using potato starch as raw material, prepare starch- base nonformaldehyde adhesive by thermal method. This research also discovers the optimal raw material configuration and process conditions under thermal method, and it contains two parts.(1) By orthogonal experiment, the optimal raw material configuration and process conditions of adhesive, as well as the factors of effect on performance of adhesive product were defined.(2) Via single-factor experiment, the influencing factors of starch adhesive's initial viscosity, adhesive strength, stability and other characteristic were analyzed and studied. In addition, by doing so, the raw material configuration and process conditions of starch adhesive were improved, and its optimal condition were determined.Based on the experiment, using 30g starch, the optimal proportioning of starch adhesive which determined by orthogonal experiment, were as follows: oxidizer (30% H2O2) charges 1.6mL, catalyst (FeSO4) charges 0.1g, water charges 150g, gelatinization agent (NaOH) charges 2.7g, oxidized time costs 60min, crosslinking agent (borax) charges 0.3g and gelatinized time costs 30min. Through the single-factor experiment, the effect factors on adhesive strength, viscosity, initial tack and stability of adhesive, were further more ascertained. Subsequently, based on above, the optimal proportioning is determined under the orthogonal experiment, and the obtained adhesive product parameters are: adhesive strength 8.65N/cm2, viscosity 39.25s, and fluffed area 100%. The adhesive far more than the demands of standard provisions of adhesive peel strength ,which is not less than 6.0N/cm2 [95].Ultimately, I added different quantity of Sodium Bentonite and polyvinyl alcohal as additives to improve properties.The result of experiment shows that the starch adhesive modified with polyvinyl alcohal are stable,and that the Adhesive strength of the starch adhesive modified adhesive is improved.It could bedried quickly. Final we choose polyvinyl alcohal as drier for quick-drying modified in the original ratio of raw materials. Based on the experiment, different dosages of addictive have different effects. And being comprehensively consideration, its effects on drying speed, as well as its cost, the optimal dosage of addictive is 5% of the starch adhesive's total mass.Oxidized starch is broad applied in many fields such as papermaking and textile. What's more, potato starch is a kind of green and renewable resource, thus, the study on potato starch adhesive has significant importance.