Studies On The Preparation And Application Of Chitosan Based Films

In the literature review part of this paper, we mainly discussed the study progressof chitosan, palygorskite and polyvinyl alcohol. Firstly, we introduced the physicaland chemical properties of chitosan, list research progress of chitosan film, such ascrosslinked film, quaternary ammonium compound film, blend film, hybridmembrane, ultrafiltration membrane and self assembled membrane. Secondly, wediscussed the characteristic of palygorskite, cited its research progress in adsorption,cocatalyst, polymerization and other areas in recent years. Finally, the physical andchemical properties of polyvinyl alcohol were also introduced, as well as its solution,film forming and application.Based on the literature review and theoretical exploration, the experimental partof the paper include the following:Bases on the above review, the dissertation included following research contents:1. Palygorskite was treated with different concentrations of acetic acid andhydrochloric acid. A new blending composite film was prepared with chitosan,acidified palygorskite and polyvinyl alcohol as raw material, and 6 methylenediisocyanate as crosslinking agent. The structure of the film was characterized by themethods of FT IR, XRD, TG DTA and SEM, meanwhile the mechannical property ofit was also tested. Compared with chitosan film, the crystallinity and transparency ofchitosan composite film has declined, and thermal stability is significantly enhanced,as well as mechanical property. We also discuss how the feed ratio, acid solution,crosslinking agent and other factors affect on composite film preperation. Theoptimum preparation condition is following: the quanlity feed ratio ofchitosan,polyvinyl alcohol, palygorskite is 1:1:1, with 10% lactic acid dissolvechitosan , crosslinking agent is HDI, temperature is 20℃.2. The behavior of chitosanβcyclodextrin membranes adsorbing o , m , and p nitrophenol in water solution were studied. The rearch emphasised on how thedifferent acidity, temperature and time conditions influenced chitosanβcyclodextrinmembranes adsorbing p nitrophenol. The result showed that the adsorption capacityto p nitrophenol of these membranes was better in neutral condition. The sorptionisotherm was fitted with the Langmuir equation and Freundlich equation. As a result,the adsorption of adsorbent to p nitrophenol was more in line with Langmuirequation.