Activating a Surface
The use of hexamthylene diisocyanate (HDI) in toluene with di-n-butyltin dilaurate (DBTDL) as a catalyst.
This creates NCO free groups.
This was preformed on polyether urethane and used to graft sulfobetaines onto it. (note the use of jeffamine spacer is used to graft sulfobetaines to the PU)
“Platelet adhesion on a polyurethane surface grafted with a zwitterionic monomer of sulfobetaine via a Jeffamine spacer”
J Yuan, J Zhu, CH Zhu, J Shen and SC Lin.
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(Hexamethylene diisocyanate – Wikipedia)
What is a jeffamine spacer?
Jeffamine spacer is a compound like polyethylene glycol (PEG) which is a soft polyether chain. It can greatly reduce interfacial energy between goal structure and surface of substrate. It also has a high mobility inaqueous environments. Poly(ethylene oxide) PEO spacers were used to achieve this, reason why jeffamine spacer is more effective is that the amino group is more active than the hydroxy group of PEO.






