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Case Study: Enhancing the performance of aromatic PU sealant prepolymers using oxazolidines
Whilst there have been a number of technical advances in the resins used in construction sealants, polyurethane chemistry continues to offer the best balance of cost and performance. The chemistry is highly versatile, with aromatic and aliphatic prepolymers offering the formulator a range of properties to meet differing performance requirements.
Some advantages PU offers over other technologies:
better mechanical strength
no toxic by products from the cure mechanism
better substrate adhesion
ease of paintability
Benefits of introducing oxazolidine latent hardeners into aromatic PU sealants:
eliminate gassing
excellent through cure in thick film applications
retain good workability of the sealant
early Shore hardness development through crosslinking
no significant impact on mechanical strength or shrinkage
no detrimental impact on UV resistance
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