The Development Of Environmentally Friendly Polyurethane Waterproof Coating

The history of polyurethane waterproof coating was used is longer, but there is some disadvantage in the normal polyurethane coating, for example harming to environment and the health of worker, lower mechanical property etc. Aim at these question, studied the preplolymer and prepared the normal room temperature cure oily two-component polyurethane waterproof coating, and be used for adhere waterproof curly material and direct waterproof layer, room temperature film forming one-component anion waterborne polyurethane waterproof coating. The four types polyurethane waterproof coating are satisfied of environment protection request.According to analyzing the infrared absorption spectroscopy and chemical component and testing mechanical property, solid content, particle size of emulsion, water absorption of latex coating and acid or alkaline processing, the main results of thesis are as follows:The synthetic reaction time is 3 hour at 75 ± 5℃, when synthesized the prepolymer. The calcium carbonate as the solid filler and the content is 15% are better and the HVGO as the liquid filler and the content is 30%. It can solve the disadvantage of blister that bring to petroleum resin as the liquid filler, when the HVGO as the liquid filler. When the petroleum resin as the liquid filler, can be the surface curing time reduced, and it is reducing with the content of it increasing.The —NCO content is 10% in the prepolymer, the calcium carbonate and petroleum resin content is 15% and 30%, use MOCA/N-330 (function group) is 0.75/0.25 as the mixed curing agent, prepared the normal room temperature cure oily two component polyurethane waterproof coating. The property is satisfied of GB/T19250—2003.HVGO replaced petroleum resin in above, prepared the polyurethane waterproof coating that is used for adhere waterproof curly material. When the breaking elongation ratio is satisfied, the tensile break strength is improved about 75%.At the condition —NCO, calcium carbonate and HVGO content don't be altered, use MOCA/EP330-N (function group) is 0.90/0.10 as the mixed curing agent, prepared polyurethane waterproof coating that used as the direct waterproof layer. It stay at 0.4MPa 2 hour is impermeability. When the breaking elongation ratio issatisfied, the tensile break strength is improved about 300%.The chain extender reaction time is 4 hour at about 55 °C, when prepared waterbome polyurethane. The —NCO content is about 10% in the prepolymer, the comprehensive property of emulsion is better. BPA/DEG (hydroxy) is 1/2 and use it as the chain extender prepared room temperature film forming one-component anion waterbome polyurethane waterproof coating. The water absorption is about 10% after continuous dip in water 168 hour. The retain quotiety of the tensile break strength and breaking elongation ratio is 71.5% and 105.7% after acid processing, 92% and 94.7% after alkaline processing, especially. The water impermeability improved that compares with using DEG as the chain extender.The normal the normal room temperature cure oily two-component polyurethane waterproof coating, and be used for adhere water-proof curly material and direct waterproof layer have characteristic of solventless, solid content more than 98%, room temperature cure, high mechanical property, good compatibility of two component. The room temperature film forming one-component anion waterbome polyurethane waterproof coating has characteristic of non —NCO, good water resistance and impermeability. They have applied value for engineering.