The Preparation Of Polysucrose Composites

In this essay, at first, two series of hydrogels were prepared from gelatin and polysucrose which has many excellent advantages, such as good biocompatibility, biodegradability, excellent hydrophilicity and low toxicity. (1)The hydrogels were prepared by mixed with the polysucrose and gelatin solutions which crosslinked by EDC. And they were characterized by FTIR, XPS, DSC, TGA, and compression tests. It was found that the polysucrose and crosslinked gelatin were stabilized by the intermolecular hydrogen interaction in the system. And the thermal and mechanical properties of the hydrogels had been significantly improved in comparison with the hydrogels prepared by neat gelatin. The compressive modulus of the hydrogel was increased from 127.7KPa to 179.5KPa. (2) The hydrogels were prepared by reaction of gelatin with oxidized polysurcose which was prepared from periodate oxidation of polysucrose. The results indicated that the crosslinking reaction was occurred between the aldehyde groups of oxidized polysucrose and theε-amino groups of gelatin. Comparing the hydrogel prepared from gelatin crosslinked by EDC, the mechanical properties of the hydrogels improved significantly.Then, a series of gelatinous polysucrose microspheres with appropriate particle size, high equilibrium water content (EWC) (57.6%-86.3%) and hydroxyl content (15-19mmol/g) were synthesized, using sucrose as raw material and epichlorohydrin as crosslinker. Their chemical structure was determined by FTIR and XPS. It is found that the EWC and the hydroxyl content of the microspheres declined when the crosslinker amount increased. Meanwhile, the affection of the reaction conditions to the productivity was also studied, and the excellent conditions were chosen.Last, the denatured sucrose with allylic groups was prepared from sucrose and allyl bromide. Their chemical structure was determined by FTIR and 13CNMR. It is found that there were allylic groups in the sucrose molecular chain. Meanwhile, the affection of the reaction conditions to the productivity was also studied, and the high productivity would be obtained when chose the below conditions: reaction time, 5h; reaction temperature, 65℃; sodium hydroxide amount, 4.5g; the ratio between allyl bromide and sucrose, 2.5:1.