Chain extenders, also known as curatives, are either hydroxyl (-OH) or amine (-NH2) terminated.
A wide variety of different cross-linkers with different reactivities can be found.
Some commonly used ones include:
M.W: 267.16
CAS: 101-14-4
Melting point: 100oC (212oF)
SG (liquid): 1.26 @ 107oC (225oF)
M.W: 214
CAS: 106264-79-3
Melting point: liquid at RT
SG (liquid): 1.21 @ 20oC (68oF)
M.W: 90.1
CAS: 110-63-4
Melting point: 20oC (68oF)
SG (liquid): 1.017
M.W: 198.22
CAS: 104-38-1
Melting point: >98oC (209oF)
SG (liquid): 1.15 @ 110oC (230oF)
M.W: 134.17
CAS: 77-99-6
Melting point: 58oC (136oF)
SG (liquid): 1.085 @ 80oC (176oF)
M.W: 1000
CAS: 25190-06-1
Melting point: 24oC (75oF)
SG (liquid): 0.981 @ 40oC (104oF)
M.W: 314
CAS: 57609-64-0
Melting point: 125oC (257oF)
SG (liquid): 1.14 @ 140oC (284oF)
M.W: 310
CAS: 5285-60-9
Melting point: Liquid at RT
SG (liquid): 0.99 @ 26.7oC (80oF)