Synthesis And Properties Of Nano-modified Waterborne Polyurethane Compositemarials

Waterborne polyurethane(referred WPU),is widely used in textiles,paints soil composite material construction sector,as the dispersion medium with water,has non-polluting,non-toxic,low power consumption,non-flammable,easy to process,good abrasion resistance and mechanical properties,.It has become one of the hot research field of polymer materials.Waterborne polyurethane composite latex were synthesized from isophorone diisocyanate(IPDI),polyester polyol(PBA),dimethylol propionic acid(DMPA),N-methylpyrrolidone ethylenediamine(EDA)by anionic self-emulsified method.Further,other particles a series of nanoparticles WPU composite emulsion obtained by adding nano-zinc oxide(ZnO),potassium titanate whisker(PTW),a silane coupling agent(KH550,KH570),microcrystalline cellulose(MCC),nano-cellulose(NCC)in the synthetic system by adding,and films obtained at room temperature,the natural air-dry conditions.And the structure was tested by infrared spectroscopy,differential scanning calorimetry,film stretching,thermal gravimetric analysis,nuclear magnetic resonance,electron microscopy and so on.After adding nano ZnO,the Si-O-Si stretching vibration absorption peak appears in the place of 1192cm-1 by analysising the infrared spectra of the composite materials,appears in place for them;the uniform core-shell structure observed completely by analysising the TEM analysis scans;which indicates the nano ZnO sticks to the molecular chain of WPU successfully.The tensile strength of WPU composite material was 38 MPa when the addition ratio of nano-ZnO was 0.3%,the elongation at break of 410%,the contact angle of water of the films reaches 83.64°,The decomposition temperature fell 50? than the pure WPU when When half of the weight loss,the molecular chain hard segment content increased to 79.46%,the overall performance of the composite film was the best.After adding PTW,the-Ti-O-Si stretching vibration absorption peak appears in the place of 956cm-1 by analysising the infrared spectra of the composite materials.The glass transition temperature of WPU composite material was reduced to-38.5? and the molecular chain hard segment content was 73.08%,when the addition ratio was 0.1%;The tensile strength of WPU composite material was 34.0 MPa and the elongation at break of 450%,when the addition ratio was 0.2%,the mechanical properties of the film was the best;the contact angle of water of the films reaches 84.91° when the addition ratio was 0.3%,the overall performance of the composite film was the best.After adding KH570,the-Si-O-stretching vibration absorption peak appears in the place of 952cm-1 by analysising the infrared spectra of the composite materials With the addition ratio of KH570 increased,the tensile strength and elongation at break of the WPU composites decreased;the water contact angle of the films reaches 89.16° at maximum,theglass transition temperatures of the films as low as-38.1?,when the addition ratio of KH570 was 1.2%;hard segment content of the WPU composite molecular chains are all slightly decreased,the KH550 caused more degradation than KH570,when adding the same proportion.The tensile strength of the WPU composite reaches 33.0 MPa at maximum and the elongation at break of the film reaches a minimum 530%,when the addition ratio of MCC was 0.2%.The tensile strength of the WPU composite reaches 32.5 MPa at maximum and the elongation at break of the film reaches a minimum 320%,when the addition ratio of NCC was 0.5%.The water contact angle WPU/MCC films has a minimum at 67.98° and The water contact angle WPU/MCC films has a minimum at 62.98°,When the addition ratio were 0.4%.