Preparation And Property Evaluation Of A Novel Antibacterial Polyurethane

Potentially harmful bacteria abound all around us. Bacteria, that attach to surfaces aggregate in a hydrated polymeric matrix of their own synthesis to form biofilms. 45% Biomaterial Centered Infections (BCI) is caused by bacteria. With modern technology, many humans will host a biomaterial, and will therefore be at risk of a biofilm infection, This biofilm may present the need for additional operations, amputation, or it may even lead to death.As the ever-growing demand for healthy living, there is a keen interest in materials capable of killing harmful microorganisms. The convention way of making materials bactericidal is to impregnate them with antibacterial agents, such as antibiotics, silver ions and iodine, which are gradually released over the time. This approach, while certainly useful, is quite limited because the leaching of antibacterial agent is eventually exhausted rendering the material ineffective and poses a potential environmental risk. Recently, intensive studies have been focused on the non-release strategy for creating bactericidal surfaces that involves covalent coating.In the light of the facts above mentioned, we envisaged that a novelpolyurethane which contains a "PEG" chain spacing , and giving bactericidal quaternary ammonium groups via C-N band to prepare polyurethane quaternary ammonium salt bactericides.In this paper, a series of polyether-based polyurethanes were synthesized with 4,4' -diphenylmethane diisocyanate(MDI), 1, 4-butanediol(BD0) as hard segment,poly(tetrahydrofuran)(PTMG) as soft segment and a novel compound—poly(ethylene glycol) with a-tertiary ammonium and "-hydroxyl groups (NPEG) as blocking agent by the method of bulk two-step process , then N-alkylated with different alkyl bromides(from methyl to hexadecyl). Fourier Transform Infraned Spectroscopy (FTIR), 'H-Nuclear Magnetic Resonance Spectra('HNMR), Gel Permeation Chromatography(GPC) and Differential Scanning Calorimetry (DSC) are used to characterize their structure. Mechanical properties, water contact angles and water adsorption tests reveal that this kind of polyurethanes not only possesses good mechanical properties but has good hydrophilicity.The antimicrobial susceptibility determination shows that the introduce of "PEG" chain spacing is helpful for polyurethane' aoility to inhibit bacteria adsorbing on the surface, and depending on the alkyl group, the resultant surfaces were able to kill up to S0% of Staphylococcus aureus cells sprayed on them.