A polymer represented by either Structure I or Structure II:
X
(NHCH
2
CH
2
)
m
-L
r
-B]
S
Structure I
wherein m is independently 2 to 500; X is an initiating group; B is independently a polymer or copolymer segment, wherein B is not poly(2-ethyloxazoline) (PEO) if its molecular weight is greater than 2,500 and B is connected to the PEI segment (NHCH2CH2)m either directly (r=0) at the end of the chain or via a linking group (r=1) at the end of the chain; L is independently a linking group; r is 0 or 1; and
s is 1 to 8;
wherein m′ is independently 2 to 500; X′ is independently an initiating group L′ is independently a linking group linking the end of the chain of the PEI segment (NHCH2CH2)m′ to G*; G is independently a polymerizable monomer; G* is a monomer unit that is copolymerizable with the G monomer; y+z is from 10 to 100,000; and 0