| The antibacterial polyethylene (PE) film was taking more and more effectin keeping quality and safety of food, extending shelf-life and improvingquality of people’s life. The main methods were the application ofantibacterial agents for preparation of antibacterial PE film. Functional PEfilm with antibacterial properties could restrain bacteria growth andpropagation on its’ surface. Most antibacterial agents played a role inrestraining or killing microorganism, such as fungi, molds, bacteria and so on.Precious metal elements antibacterial agent, which were gained more attentionsuch as nano-Ag，nano-ZnO and nano-TiO2, had some difficults in preparationof antibacterial PE film because of its’ high production cost. This researchwould study the antibacterial PE film with a cheap inorganic antibacterialagent. Basic magnesium hypochlorite particles (BMHs) has many advantagessuch as low solution, thermo-stability，nonirritant and excellent antimicrobialproperties. In compare with other antibacterial, BMHs were a good choicebecause of simple preparation and low cost. The main studies were as follows:1. The micro-emulsion method was used to study the preparation ofnano-particles. BMHs was synthesized by the reaction between1ml0.4MMgCl2and1.1mL NaClO (10%) for5h under the constant20oC in W/Omicro-emulsion solution containing3mL OP,15mL hexane,3mL n-amylalcohol. The products were characterized by means of scanning electronmicroscope (SEM) and Malvern Instruments. The results indicated that BMHswas spherical particle and had uniform particle size and the average size wasabout80nm. The antibacterial properties of the BMHs were tested and theresults indicated that the MBC of the BMHs on escherichia coli (E. coli) andstaphylococcus aureus (S. aureus) were1250μg/mL, the antibacterial rate ofthe BMHs against E. coli reached99.2%for6h and reached99%for3hagainst S. aureus. The excellent antimicrobial activity of BMHs nano-particlesmight be caused by synergistic effect of reactive oxygen species (ROS) andphysical absorption.2. The BMHs were modified with sodium stearate acted as surfactant.The influence of the main technical parameters such as the addition amount of sodium stearate, reaction temperature and reaction time were investigated. Thecharacteristics of the modified BMHs were analyzed by means of watercontact angle measurements, lipophilic degree, Fourier transform infraredspectroscopy (FT-IR) and thermogravimetry (TG). The antimicrobial activitiesof modified BMHs were investigated by the antibacterial circle test. Theresults showed that BMHs had been successfully modified by sodium stearateand the lipophilic degree of modified BMHs was8.4%when the additionamount of sodium stearate was0.15g, the reaction temperature was10oC andthe reaction time was5h. The dispersibility and hydrophobicity of themodified BMHs were improved and the contact angle was up to103o, themodified BMH still had excellent antimicrobial activity after modification.3. Antibacterial PE film was prepared by solvent casting method withtrichloroethylene as solvent and BMHs as filling. The influences of amountaddition of BMHs, range from0.5%,1%,1.5%,2%and2.5%, on themechanical properties of PE film were investigated. After surfacemodification by sodium stearate, BMHs was well comparable with PE plasticand uniformly distributed in the PE film. The results indicated that theantibacterial PE film had better mechanical properties without influence oncrystallization temperature of PE resin as the addition of BMHs was1%. Theantibacterial test showed that the antibacterial PE film with1%BMHs hadexcellent and long-acting antibacterial activity，and the antibacterial rate offilm samples were all above60%against E. coli and S. aureus. Compared withnormal PE film, the tensile strength and tear strength of antibacterial PE filmwere little affected. |
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