Abstract:
Waterborne polyurethanes modified by maleopimaric acid (MWPU) were prepared from maleopimaric acid polyester polyols (MAPP) and toluene diisocyanate by acetone method. The effects of NCO/OH value (R value), DMPA amount and MAPP amount on the properties of MWPU emulsions and MWPU films were studied respectively. The properties of the products, such as tensile strength, pendulum hardness, elongation at break, water resistance and heat resistance, were characterized. The comprehensive properties of MWPU were tensile strength 23.2 MPa, pendulum hardness 0.7, elongation at break 569%, water absorption 14.2% and 5% weight loss at 258℃ on condition of DMPA mass fraction 5%, R value 1.3, and the amount of MAPP 30%.