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Preparation and Properties of Waterborne Polyurethane/Nano-ZnO Composites

Author: MaXueYong
Tutor: ZhangWeiDe
School: South China University of Technology
Course: Applied Chemistry
Keywords: Composites Enhanced modified Situ polymerization Waterborne Polyurethane ZnO nanomaterials
CLC: TB383.1
Type: Master's thesis
Year: 2010
Downloads: 361
Quote: 1
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Abstract

With traditional organic solvent-based polyurethane, compared waterborne polyurethane (WPU) with non-polluting, non-toxic, non-flammable and so on. The zinc oxide (ZnO) as a multifunctional inorganic nanomaterials, in many areas has broad application prospects, especially in closely related to human health photocatalytic degradation of organic pollutants and antibiotic has a unique advantage. Therefore, the zinc oxide added to the aqueous polyurethane can be prepared in anticipation to get superior performance of composite materials. This thesis is regulated by a simple hydrothermal reaction conditions were prepared ZnO nanorods, nano-needles, nanosheets, nanoparticles, hexagonal plates and flower clusters like ZnO morphology of six different zinc oxide nanomaterials. On the preparation of the materials were obtained X-ray diffraction, scanning electron microscopy and transmission electron microscopy characterization. Samples for UV photocatalytic degradation of methyl orange results show that ZnO nanorods and nanosheets have better photocatalytic performance, while flower clusters like ZnO photocatalytic worst performance. Based on the experimental results of a preliminary exploration of the morphology of ZnO nanomaterials its photocatalytic performance. Zinc oxide material in order to better disperse in the aqueous polyurethane matrix, the use of γ-aminopropyl triethoxysilane zinc oxide nano materials for surface modification, the introduction of reactive amino groups; followed by the action of the catalyst amino group with the surface of zinc oxide isophorone isocyanate-reactive isocyanate groups grafted onto the surface of zinc oxide nano-materials, preparation of composite materials for the next play a key role. Successfully prepared by in situ polymerization to obtain an aqueous polyurethane / zinc oxide nanorods (WPU / ZnO-rods) composite materials. When the content of zinc oxide nanorods low (≤ 1.0 wt%), zinc oxide nanorods can be uniformly dispersed in the WPU matrix. WPU film with respect to the blank, when the additive amount of ZnO nanorods 1.0 wt%, the tensile strength of the composite increase the maximum. As the content of ZnO nanorods increase, WPU / ZnO-rods composites and improve water resistance; however, the addition of zinc oxide nanorods WPU matrix filling the lower the thermal stability. WPU / ZnO-rods composite Another prominent feature is the excellent antibacterial properties, when the content of ZnO nanorods 2.0 wt%, the composite material against Escherichia coli and Staphylococcus aureus antibacterial rate increased to 99% or more . Three-dimensional microstructure of flower clusters like ZnO whisker (f-ZnO) having a high mechanical strength, wear, vibration, and other unique antibacterial properties, so it can be added to the polymer in the preparation of functional composite materials. Prepared by in situ polymerization of an aqueous polyurethane / flower cluster like zinc oxide whiskers (WPU / f-ZnO) composites mechanical strength, thermal stability, water resistance and antimicrobial activity and other properties are subject to f-ZnO added amount of . With the f-ZnO content increased, WPU / f-ZnO composite water resistance and antimicrobial activity will be improved, the thermal stability decreases; tensile strength at first increased and then decreased along with the trend, when the f- The content of ZnO is 1.0 wt%, WPU / f-ZnO composite tensile strength of max. In order to study the morphology of ZnO on the WPU / ZnO nanocomposite performance, we also adopted the in situ polymerization of waterborne polyurethane / zinc oxide nanosheets (WPU / ZnO-sheets), waterborne polyurethane / oxidation Zinc nanoneedle (WPU / ZnO-needles) and waterborne polyurethane / zinc oxide nanoparticles (WPU / ZnO-particles), three composite materials. Test results showed five different morphology of zinc oxide on the WPU / ZnO nano-composite mechanical properties, thermal stability, water resistance as well as E. coli and Staphylococcus aureus antibacterial properties are affected. When different morphology of zinc oxide content of 1.0 wt% were when, WPU / ZnO nanocomposites tensile strength relative to the WPU matrix have improved to varying degrees; wherein the three-dimensional structure of the f-ZnO substrate stretch for WPU the strongest intensity, while nanoparticles enhance the weakest. Adding zinc oxide material reduces the thermal stability of the substrate WPU; wherein, WPU / ZnO-sheets worst thermal stability of the composite material, the WPU / ZnO-needles composites best thermal stability. In addition, the nano particles on the substrate WPU enhancement of the best water resistance, and the reinforcing effect of f-ZnO worst. Add 5 different morphology of zinc oxide-reinforced composite material can Escherichia coli and Staphylococcus aureus antibacterial effect, and the antibacterial activity of the composite zinc oxide added with the increasing of the amount; wherein WPU / ZnO-sheets Composites strongest antibacterial effect, WPU / f-ZnO composite antibacterial effect is the weakest. The preparation of a series of papers with strong mechanical properties, water resistance and antimicrobial properties of WPU / ZnO nanocomposites and studied ZnO in WPU matrix and the dispersed state of content on the properties of composite materials. This thesis work on the future new multifunctional nanocomposites study provides a good reference value.

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