The Modification Of Waterborne Polyurethane And Its Application On Fabric Coating

In this dissertation, waterborne polyurethane was prepared from polyols(E220/E210) and toluene-2,4-diisocyanate(TDI) and dimethylol propionic acid (DMPA) as anionic hydrophilic center. In the synthesis process, methyl acrylate or hydroxyethyl acrylate or the mixture of the two was added. The PU film was tested by the analysis of FTIR , DSC ,X -ray and its mechanical properties such as strength and elongation were tested. In addition, the particle size ,the viscosity and the stability of PU emulsion were tested .All the results showed the formation of chemical bonds among monomers and molecule chains of PA and PU .The film had good strength and its water absorption decreased when methyl acrylate was introduced . The film had good elongation and its water absorption and the molecular weight increased when hydroxyethyl acrylate was introduced. Excellent properties of PU was obtained by optimizing the amount of the two materials. The effects of different chemical composing on performances, the effects of the particle size and the viscosity on the stability of emulsion were also studied. The stability and mediums resistance of the modified-PU emulsion decreased. Amine as chain extender for acrylic acid monomer introduced into the molecule chain of PU was studied, and the result tell us that the material choice and the synthesis condition are the key factors.PU and modified-PU were applied on cotton coating. Whiteness , breathability and moisture permeability of the cotton decreased while water pressure resistance ,strength and elongation of the cotton increased after coating . The effects of the technological factors on coating application werestudied such as temperature, time and coating amounts ,and so on. With hydroxyethyl acrylate increasing, moisture permeability increased. With methyl acrylate increasing, water pressure resistance and waterproof increased.