Silicone-modified polyurethane dispersions for wood, plastic and automotive applications are reported as produced in an N-metriyl-2-pyrrolidone-free synthesis. The method uses the silicone building block, dihydroxy alkyl polymethyl siloxane as the dihydroxyl macrodiol. The choice of the macrodiol with silicone backbone is important since too low molecular weight has no property impact, while a too high molecular weight gives serious incompatibility problems. The process has 3 steps: 1) a polyaddition of the diols carried out with isocyanate and dimethylol propionic acid to yield a polymer with isocyanate terminal groups, 2) the obtained backbone having acid groups is neutralised with a tertiary amine to yield a neutralised backbone, 3) the polymer backbone is emulsified witli water to yield a high molecular backbone and a stable polyurethane dispersion.
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