The Preparation Of Modified Polyurethane Prepolymer For Automobile

Auto glass adhesive is mainly prepared by polyurethane prepolymer,the curing polyurethane prepolymer has the advantages of high strength,tear resistance,abration resistance and weather resistance.With the development of auto industry,some problems exist in using,for example,the curing polyurethane will generate bubbles and it's hard to storage and easy to produce mildew.With the development of auto industry,the car factories put forward higher demands to auto glass adhesive.At present,the auto glass adhesive which is mainly made of polyurethane prepolymer is easy to generate bubbles and mould,it will affect the quality of cars.Therefore,it's important to the development of polyurethane prepolymer.In this paper,the author use silane coupling agent and thiophene derivatives to modify the polyurethane prepolymer,and characterized the modified polyurethane prepolymer by means of FT-IR,TGA,SEM and DMA,studied the mechanical properties and mildew proof properties of the modified polyurethane prepolymer,then prepared the auto glass adhesive by the modified polyurethane prepolymer and researched its properties.The structures of silane coupling agent show as follows:(?)The results show that compared with the unmodified polyurethane prepolymer,the mechanical properties of the silane modified polyurethane improved obviously.Its hardness improved 60%,the tensile strength improved 65%,the elongation improved 87%.The unmodified polyurethane prepolymer produced bubbles and the modified polyurethane prepolymer didn't exist the phenomenon.Compared with the unmodified polyurethane prepolymer,the antibacterial rate to colibacllus and staphylococcus aureus of the modified polyurethane prepolymer improved obviously.Its antibacterial rate for colibacllus increased from 20% to 68%,and for staphylococcus aureus the antibacterial rate increased from 25% to 74%.The auto glass adhesive prepared by the modified polyurethane prepolymer didn't appear bubbles during the curing process.The mechanical performances of auto glass adhesive was better than the unmodified polyurethane adhesive.Its hardness was 45 MPa,the tensile strength was 3.02 MPa,the elongation was 435% and the shearing strength was 5.15 MPa.What's more,the auto glass adhesive has adhesive properties,medium resistance,salt/fog resistance and aging resistance.It showed that the auto glass adhesive's performances meet the standards of the auto industry.It had important application value.