Hybrid Polyurethane-urea

Synthesis and Characterisation of Aqueous Hybrid Polyurethane-Urea-Acrylic/Styrene Polymer Dispersions... 

Synthesis and Characterisation of Aqueous Hybrid Polyurethane-Urea. 

Hybrid polyurethane-urea-acrylic/styrene polymer dispersions were prepared according to methods la , lb , 2 and 3 described in Section 6.3.2. Dispersions designated as MDPUR-ASD were made by polymerisation of monomers in DPU according to the methods la, lb and 2 while dispersions designated as MDPUR were made by synthesis of DPUR in ASD according to method 3. In all syntheses the ratio of polyurethane-urea to acrylic/styrene polymer in the hybrid was 2 1. 

Figure 6.19 DSC thermogram for typical hybrid polyurethane-urea-acrylic/styrene dispersion synthesised in this study (MDPUR-ASD 97 prepared according to method 2...

Synthesis and Characterisation of Aqueous Hybrid Polyurethane-Urea... 6.S.3.3 Chemical Structure of the Polyurethane-Urea Portion of the Hybrid (a) Effect of Dolvol type... 

Figure 6.23 Particles of hybrid polyurethane-urea-acrylic/styrene dispersion prepared according to method la using less hydrophobic monomer and water-soluble initiator (MDPUR-ASD 22). Photograph was taken using TEM.

Figure 6.31 Examples of different morphologies of particles of hybrid polyurethane-urea-acrylic/styrene dispersions synthesised in this study. Micrographs were taken...

Figure 6.32 Morphology of particles of hybrid polyurethane-urea-acrylic/styrene hybrid dispersion prepared according to method 2 (See Section 6.3.2) using water-soluble initiator (MDPUR-ASD 97). Micrograph was taken using TEM. Both single particle and coalesced particles are shown. Reproduced with permission from Professor A. E. Czalych, Institure of Chemical Physics of the Russian Academy of Sciences, Moscow.

Generally, based on the results shown above, it can be concluded that introducing double bonds into polyurethane-urea is undoubtedly one of the ways to obtain coatings of excellent properties based on hybrid polyurethane-urea-acrylic/styrene dispersions. 

In this study, aqueous hybrid polyurethane-urea-acrylic/styrene polymer dispersions were obtained using four different methods. The dispersions are stable and their viscosity, and pH as well as average particle size and particle size distribution are similar to those observed for DPUR. Most of the hybrid dispersions formed transparent films of good mechanical properties, water resistance and organic solvent resistance. 

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See also in sourсe #XX -- [ , ]

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