Study On Synthesis Of Poly Malic Acid

Poly (malic-acid) is a sort of polyester and absolute biodegradable material. After degradation, it stays trace scarcely, and the degradation products are avirulent and harmless. It was potential wrapper. Poly (malic-acid) has extensive application. It can be used as the medicine carrier and tiny capsule materials, medical bio-materials, absorbent water materials, cosmetic product and the inhibitor of some microorganisms'DNA. Poly (malic-acid) has mostly three kind of structures, namely the α, β, γ. Poly (β-malic-acid) was discovered in natural and some living bacterium, another two kind were synthesized in lab, And only poly (β-malic-acid) has bio-compatibility. Of the three kind of structures, poly (β-malic-acid) particularly was the most widely used, Now, study on poly (β-malic-acid) has a little bit hot. The raw materials of synthesis of poly (β-malic-acid) were more, but the methods of synthesis were all the ring-opening polymerization, β-alkaneoxycarbonyl-β-propiolactone as the monomer adding initiator. So the most important thing was to find out a simple and economic route to synthesize the β-alkaneoxycarbonyl-β-propiolactone before we wanted to synthesize the poly (β-malic-acid). In the thesis, we studied on the synthesis of the β-benzyloxycarbonyl-β-propiolactone on the base of my laboratory research, choosing malic acid as raw material, with economy and simple operation for intention. Two routes of alterant Mitsunobu reaction and chloro-substituting of malic acid to synthesize theβ-benzyloxycarbonyl-β-propiolactone were studied. We discussed the craft and method. Identified the products by MP,IR,and H NMR et al. In the alterant Mitsunobu reaction route, trifluoroacetic anhydride(TFAA) was replaced by cheap acetic chloride. We synthesized the β-benzyloxycarbonyl-β-propiolactone by dehydrateion of malic acid, esterification and Mitsunobu reaction. Yield was 32.2% The route was short and cost price was reduced. The other route from chlorosuccinic acid toβ-propiolactone was longer but cost price was lower, This route was firstly reported about synthesis of chlorosuccinic acid from malic acid, then esterification of the carboxyl of the succinic acid, lactonization of the benzyl-chlorosuccinate in the alkali condition pH 7.3. Yield was 3.5% In the thesis, poly (β-benzyl-malate) was synthesized from the corresponding monomers, β-benzyloxycarbonyl-β-propiolactone, by anionic ring-opening poly merization, 0.1 wt% benzoate tetraethylammonium as initiator, for the temperature about 60℃and for the time more than 6 days. And poly (β-malic-acid) was synthesized by hydrogenolysis of poly (β-benzyl-malate), palladium (Pd)-carbon(C) as catalyst, in hydrogen at room temperature. Poly (γ-malic-acid) was synthesized, in the condition of malic acid as the raw material, 0.29wt% SnCl2 as initiator , for the temperature more than 110℃, in vacuum environment. Yield was 90%.