Polyurethane-Keratin Membranes: Structural Changes by Isocyanate and pH, and the Repercussion on Cr(VI) Removal

Table 1

Nomenclature and components of polyurethane-keratin membranes.

Isocyanate type	Dialyzed keratin solution	Water	pH of keratin solution	Membrane nomenclature
TDI 3 g	—	2.3 cm^3	—	TPH
TDI 3 g	2.3 cm^3	—	6.0	TPKN
TDI 3 g	2.3 cm^3	—	2.5	TPKAc
TDI 3 g	2.3 cm^3	—	9.5	TPKAl
MDI 5.7 g	—	0.2 cm^3	—	MPH
MDI 5.7 g	2.3 cm^3	—	6.0	MPKN
MDI 5.7 g	2.3 cm^3	—	2.5	MPKAc
MDI 5.7 g	2.3 cm^3	—	9.5	MPKAl