Preparation And Characterization Of A Novel Anti-Microbial Polyurethane Packaging Film

The polyurethane was synthesized from4,4’-diphenylmethane diisocyanate and cetomacrogol2000in this subject. Chemical characterization was done about the resulting polyurethane. And then the polyurethane with adding dodecyl trimethyl ammonium chloride was casted to films to get a kind of antimicrobial polyurethane films which can be used in packaging.Firstly, the polyurethane was synthesized by using MDI and PEG2000as the raw materials,1,4-butanediol as the chain extender and N, N-dimethyl formamide as the dissolvent. The orthogonal experiment was designed for the whole process of synthesis. The single factor experiments, which include the quality of MDI to the PEG2000, the temperature before adding the BDO, the temperature after adding the BDO and the reaction time, was tested firstly. Then the orthogonal experiment was did about the four factors. And the result shows that the optimum conditions of the synthesis is when the quality of MDI to the PEG2000is10:30(the ratios of their molar mass is2.664:1), the temperature before adding the BDO is75℃, the temperature after adding the BDO is95℃and the reaction time is4h. The dominant influence in the process of synthesis is the quality of MDI to the PEG2000, follwed by the temperature before adding the BDO and the reaction time, and the minimal impact is the temperature after adding the BDO.The IR spectrum and the HNMR spectrum were done for the product. The results of the two tests all show that it is the polyurethane and there are no observable side reaction products.Then the polyurethane with bacteria inhibitor was casted to films. Besides, the process and the ratio of raw materials were optimized. Finally, the antimicrobial polyurethane films are prepared successly. The test of sense that transmittance/haze of films were tested and the result is that the transparency of antimicrobial polyurethane films is lower than the polyurethane films. Besides, the antibacterial properties of the films to bacteria and mildew were studied. This study demonstrates that the antibacterial properties of the films with bacteria inhibitor have been raised distinctly. The antibacterial properties of the films become more distinctly by the increase of the addition of bacteria inhibitor. And the result of Measurement of material mechanical performance shows that as regarded other frequently used films, this kind of film has the good tensile strength while it has high elongation at break. And the obstructing performance of films were tested and the data displays that the oxygen permeability coefficient and the water vapor permeability coefficient of films all can decrease by the increase of the addition of bacteria inhibitor.