Study On Preparation And Properties Of The Fully Vegetable Oil-based Polyurethane Water Dispersion

Polyurethane (PU) is a very unique polymer, which has many advantages, such as wear resistance, corrosion resistance, tear resistance, oil resistance, flexibility, and other characteristics. Desired performance can be obtained according to the different performance requirements by adjusting the ratio of hard segment and the soft segment of the polymer. With the increasing depletion of oil resources and international oil prices continue to rise, seeking renewable raw materials to prepare polyurethane has become an inevitable trend. Vegetable oil as renewable resource is a mixture of fatty acid triglyceride and it has wide source, low processing cost, environmental friendly and biodegradable. As it contains large amounts of group that could modified, which is favored by many researchers. In this paper, a fully vegetable oil-based polyurethane water dispersion was prepared using vegetable oil and its derivatives as starting materials, mainly in the following aspects of the work and research:1.Study on preparation and properties of the fully castor oil-based polyurethane water dispersionUndecylate diisocyanate and hydrophilic castor oil chain extender was prepared using undecenoic acid, castor oil and 3-mercaptopropionic acid by thiol-ene click chemistry method and Curtius rearrangement. A fully castor oil-based polyurethane water dispersion with renewable carbon content of 87.7% was prepared using undecylate diisocyanate and hydrophilic castor oil chain extender to react with castor oil; influence factors of the monomer synthesis process was discussed and best reaction condition s was obtained. The synthetic monomer was characterized by fourier transform infrared spectrometer (FT-IR) and nuclear magnetic resonance (NMR). The thermodynamic performance of film was test by thermogravimetric analyzer (TGA) and differential scanning calorimetry (DSC). Water resistance, toluene swelling rate, tensile strength and other performance of the film was texted and compared with petroleum based polyurethane film. The research results showed that:The pure castor oil based polyurethane coating with water absorbing rate of only 1.75% when it soak 168h, elongation at break 32.1%, tensile strength 0.6Mpa, gel content reached 95%.2.Study on preparation and properties of the fully canola oil-based polyurethane water dispersionManageable number of functional groups of canola oil-based isocyanate, canola oil-based polyols and canola oil-based hydrophilic chain extenders was prepared using canola oil, mercaptoethanol and 3-mercaptopropionic acid by thiol-ene click chemistry method and Curtius rearrangement, then a fully canola oil-based polyurethane water dispersion with renewable carbon content of 87.6% was prepared. Moreover, canola oil-based monomer was used to react with petroleum-based monomer to verify the compatibility. Influence factors of the monomer synthesis process was discussed and got the best reaction conditions. The synthesis monomer was characterized by FT-IR and NMR. The thermodynamic performance of the film was test by TGA and DSC. The research results showed that:The pure canola oil-based polyurethane coating was tacky, which has the potential application value in the field of adhesives; due to the introduction of petroleum based monomer, increased glass transition temperature and decreased viscosity of the semi plant oil based polyurethane was obtained.