Tupperware is usually polyethylene, and as Ken has already said that is not gluable using any normal household sort of glue. At an industrial/manufacturing level you could try contacting Loctite to see what they have. but even with their specialised adhesives the bond will not be strong.
You could try 'welding' the two bits together - melting the two bits in contact with each other, but the results would be not pretty and doing that is extremely hard.
Sorry, but this is not a project with much hope of success, apart from the duct tape idea.