Study On Synthesis Of Rosin-based Complexes And Application In Immobilizing Enzyme

Rosin is a kind of natural regenerated resin which is chiefly composed of about 90% rosin acids (levopimaric acid, neoabietic acid and pulustic acid). Rosin derivatives could be modified by the double bonds and carboxyl groups of rosin acids. Rosin and its various derivatives are widely used in paints, printing inks, pharmacy, papermaking, cosmetics and so on. This thesis presents the preparation of rosin-based complexes and their applications for immobilizing enzyme. The main contents are listed as the following:1. Malaya rosin grafted ethylene glycol ester polymer (MEEP) was synthesized by malaya rosin and ethylene glycol as materials with FeCl₃as catalyst. Through the study of the influence of reaction factors on acid value and softening point of the product, the suitable synthetic conditions were as follow: the molar ratio of malaya rosin to ethylene glycol was 1: 1.2, catalyst amount was 8.3% based on total materials (mass), suitable reaction time was 30 h under 180℃. The structure of MEEP was testified by UV and IR. The four complexes including MEEPCa²⁺, MEEPCu²⁺, MEEPNi²⁺ and MEEPMg²⁺ were prepared respectively. The contents of elements Ca, Cu, Ni and Mg in complexes were determined by atomic absorption spectrometry, and the complexes were characterized by thermo- gravimetric analysis.2. The enzymes such as amylase and rhus laccase were immobilized on the complexes of MEEP respectively. Their properties were compared with the immobilized enzyme and the free one. The results showed the immobilized amylase on MEEPCa²⁺ and the immobilized rhus laccase on MEEPCu²⁺had better properties, the optimum temperature was higher 10℃ than that of free one; The suitable pH value of immobilized enzyme was related to the ion in complexes.3. A series complexes of polymerized rosin (PR) were synthesized and used for immobilizing amylase and rhus laccase. Their properties were evaluated; the experimental results showed that the immobilized amylase on the calcium complexes with PRCa²⁺ and the immobilized rhus laccase on PRCu²⁺ had better performance.4. The oxidation of tannic acid catalyzed by rhus laccase was studied through spectrophotometer. The effects of conditions such as pH value, temperature, and...