Synthesis of Star Hydrophobically Modified Acrylamide Copolymer and its Dilute Solution Behavior in Water

The primary objective of this work was to prepare star copolymers of acrylamide and N, N-dimethyl-N-vinylnonadecan-1-aminium chloride(C(18)DMAAC) and to investigate the dilute solution behavior of these star hydrophobically modified acrylamide (SHMPAM) copolymers with different C(18)DMAAC content. The SHMPAMs were prepared using photopolymerization. For the different polymer solutions, the relationship between specific viscosity and polymer concentration obeyed the Rabin's relation well, which means that the conformations of these polymer chains were nearly spherical in dilute solution. The data of these dilute solutions were fitted by four different equations. The results showed that Schulz-Blaschke(S-B) and Fedors equations more accuratly described the dilute solution properties of these kinds of copolymers. The intrinsic viscosities calculated by different equations were different from each other, which is different from the results found for linear HMPAM. The equivalent hydrodynamic volume (voluminosity V-E) of these star copolymer solutions can not calculated by the regular method because the relationship between Y (Y = (eta(0.5)(r)-1)/C (1.35 eta(0.5)(r)-0.1), eta(r) is relative viscosity and C is polymer concentration) and polymer concentration was abnormal.