Waterborne thermosensitive polyurethane and preparation method thereof

Abstract

The invention relates to waterborne thermosensitive polyurethane and a preparation method thereof. The preparation method comprises the following steps: S1, adding N-isopropylacrylamide and diethanolamine into a reaction vessel in proportion so as to obtain a dihydroxy containing thermosensitive monomer molecule B2 under proper conditions; and S2, dissolving polycarbonate diol and dimethylolpropionic acid in acetone in a reaction vessel equipped with a reflux condenser in proportion, carrying out heating, carrying out uniform mixing under stirring, then adding toluene diisocynate and a catalyst, carrying out a reaction so as to generate polyurethane, then adding the thermosensitive monomer B2 obtained in the S1, carrying out a reaction for 2 h or above, adding triethylamine and carrying out neutralizing, then adding water and carrying out emulsifying, and carrying out rotary evaporation and removing the acetone so as to obtain the waterborne thermosensitive polyurethane. The inventionhas the following beneficial effects: the dihydroxy containing thermosensitive monomer molecule is firstly employed to combine with a polyurethane chain segment; the thermosensitive monomer B2 is distributed at the end part and central part of finally-obtained thermosensitive polyurethane; the molecular weight of the obtained thermosensitive polyurethane is not restricted; thus, the waterborne thermosensitive polyurethane with long chain length can be obtained.

Description

technical field [0001] The invention belongs to the field of polymer materials, and in particular relates to a water-based temperature-sensitive polyurethane and a preparation method thereof. Background technique [0002] Water-based temperature-sensitive polyurethane is a new type of intelligent material, which combines the excellent mechanical properties of polyurethane (PU) and the temperature sensitivity of temperature-sensitive substances. It has good water solubility, low environmental pollution, non-flammability, and good It has the advantages of viscosity, high strength and good wear resistance. In addition, it also has the characteristics of intelligent temperature stimulus responsiveness and shape memory effect. In recent years, waterborne thermosensitive polyurethane has become a research hotspot and has been widely used in coatings and biomaterials. [0003] At present, environmental stimulus-responsive polymer materials are attracting more and more attention. W...

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Problems solved by technology

[0004] The method for synthesizing water-based temperature-sensitive polyurethane in the prior art is usually to combine polyurethane segments with polymer segments with temperature-sensitive properties. The disadvantage of this method is that the above two polymer segments need to be synthesized separately, and then Carry out grafting reaction, the synthesis method is relatively complicated, and the production cost is high

Chinese invention patent CN106700026A discloses a linear temperature-sensitive polyurethane and its preparation method, trying to block the polyurethane chain segment with a monomer molecule having a temperature-sensitive effect, and the obtained polyurethane has a good temperature-sensitive effect, and the synthesis method is simple , The synthesis cost is relatively low, which solves to a certain extent the deficiency in the preparation of temperature-sensitive polyurethane by grafting two polymer segments in the prior art, but this method still has shortcomings: because the temperature-sensitive monomer molecule is only connected to the polyurethane segment In order to have a better temperature-sensitive effect, the length of the polyurethane chain segment is greatly limited, so this method is only suitable for the production of temperature-sensitive polyurethane with shorter molecular chains, and the polyurethane with shorter molecular chains is mechanically The strength, viscosity and wear resistance are all reduced by different procedures, which may not meet the requirements of practical applications.

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